We present a cosmological zoom-in simulation targeting the high redshift compact progenitor phase of massive galaxies, with the most massive galaxy reaching a stellar mass of $M_{\star}=8.5\times 10^{10} \ M_{\odot}$ at $z=5$. The dynamics of supermassive black holes (SMBHs) is modelled from seeding down to their coalescence at sub-parsec scales due to gravitational wave (GW) emission by utilising a new version of the KETJU code, which combines regularised integration of sufficiently massive SMBHs with a dynamical friction subgrid model for lower-mass SMBHs. All nine massive galaxies included in this study go through a gas-dominated phase of early compaction in the redshift range of $z\sim 7-9$, starting at stellar masses of $M_\star\gtrsim 10^8\ \mathrm{M}_\odot$ and ending at a few times $M_{\star}\sim 10^9\ \mathrm{M}_\odot$. The sizes, masses and broad band fluxes of these compact systems are in general agreement with the population of systems observed with JWST known as `Little Red Dots'. In the compact phase, the stellar and SMBH masses grow rapidly, leading to a sharp decline in the central gas fractions. The outer regions, however, remain relatively gas-rich, leading to subsequent off-centre star formation and size growth. Due to the very high central stellar densities ($ρ_{\star}\gtrsim 10^{13}\,\mathrm{M_\odot/kpc^3}$), the SMBHs merge rapidly, typically just $\sim 4-35\ \mathrm{Myr}$ after the SMBH binaries have become bound. Combining KETJU with the phenomenological PhenomD model resolves the complete evolution of the GW emission from SMBH binaries through the Pulsar Timing Array frequency waveband up to the final few orbits that produce GWs observable with the future LISA mission.

Time-delay cosmography leverages strongly lensed quasars to measure the Universe's current expansion rate, H_0, independently from other methods. While the latest TDCOSMO results relied mainly on quadruply lensed quasars, doubly lensed systems are far more common and offer precise time delays, potentially enlarging the usable sample by a factor of five and enabling percent-level constraints on H_0. We present the first TDCOSMO analysis of a doubly imaged source, HE1104-1805, including the measurement of the four necessary ingredients. First, by combining 17 years of data from the SMARTS, Euler and WFI telescopes, we measure a time delay of 176.3\pm 10.8 days. Second, using MUSE data, we extract stellar velocity dispersion measurements in three radial bins with up to 5% precision. Third, employing F160W HST imaging for lens modelling and marginalising over various modelling choices, we measure the Fermat potential difference between the images. Fourth, using wide-field imaging, we measure the convergence added by objects not included in the lens modelling. Hence, we measure the time delay distance and the angular diameter distance to the deflector, favouring a power-law mass model over a baryonic and dark matter composite model. The measurement was performed blindly and yielded H_0 = 64.2^{+5.8}_{-5.0} x $λ_{int} km s^{-1} Mpc^{-1}, where λ_{int} is the internal mass sheet degeneracy parameter. This is in agreement with the TDCOSMO-2025 milestone and its precision for λ_{int}=1 is comparable to that obtained with the best-observed quadruply lensed quasars (4-6%). This work is a stepping stone towards a precise measurement of H_0 using a large sample of doubly lensed quasars, supplementing the current sample. The next TDCOSMO milestone paper will include this system in its hierarchical analysis, constraining λ_{int} and H_0 jointly with multiple lenses.

Massive stars play a significant role in different branches of astronomy, from shaping the processes of star and planet formation to influencing the evolution and chemical enrichment of the distant universe. Despite their high astrophysical significance, these objects are rare and difficult to detect. With Gaia's advent, we now possess extensive kinematic and photometric data for a significant portion of the Galaxy that can unveil, among others, new populations of massive star candidates. In order to produce bonafide bright (G magnitude <12) massive-star candidate lists (threshold set to spectral type B2 or earlier but with slight changes in this threshold also explored) in the Milky Way subject to be followed up by future massive spectroscopic surveys, we developed a Gaia DR3 plus literature data based methodology. We trained a balanced random forest (BRF) with the spectral types from the Skiff compilation as labels. Our approach yields a completeness of ~80% and a purity ranging from 0.51 ± 0.02 for probabilities between 0.6 and 0.7, up to 0.85 ± 0.05 for the 0.9─1.0 range. To externally validate our methodology, we searched for and analyzed archival spectra of moderate- to high-probability (p > 0.6) candidates that are not contained in our catalog of labels. Our independent spectral validation confirms the expected performance of the BRF, spectroscopically classifying 300 stars as B3 or earlier (due to observational constraints imposed on the B0─3 range), including 107 new stars. Based on the most conservative yields of our methodology, our candidate list could increase the number of bright massive stars by ~50%. As a byproduct, we developed an automatic methodology for spectral typing optimized for LAMOST spectra, based on line detection and characterization that guides a decision path.

Cosmology from weak gravitational lensing has been limited by astrophysical uncertainties in baryonic feedback and intrinsic alignments. By calibrating these effects using external data, we recover non-linear information, achieving a 2% constraint on the clustering amplitude, $S_8$, resulting in a factor of two improvement on the $Λ$CDM constraints relative to the fiducial Dark Energy Survey Year 3 model. The posterior, $S_8=0.832^{+0.013}_{-0.017}$, shifts by $1.5σ$ to higher values, in closer agreement with the cosmic microwave background result for the standard six-parameter $Λ$CDM cosmology. Our approach uses a star-forming 'blue' galaxy sample with intrinsic alignment model parameters calibrated by direct spectroscopic measurements, together with a baryonic feedback model informed by observations of X-ray gas fractions and kinematic Sunyaev-Zel'dovich effect profiles that span a wide range in halo mass and redshift. Our results provide a blueprint for next-generation surveys: leveraging galaxy properties to control intrinsic alignments and external gas probes to calibrate feedback, unlocking a substantial improvement in the precision of weak lensing surveys.

This White Paper outlines a coordinated, decade-spanning programme of hadron and QCD studies anchored at the GSI/FAIR accelerator complex. Profiting from intense deuteron, proton and pion beams coupled with high-rate capable detectors and an international theory effort, the initiative addresses fundamental questions related to the strong interaction featuring confinement and dynamical mass generation. This includes our understanding of hadron-hadron interactions and the composition of hadrons through mapping the baryon and meson spectra, including exotic states, and quantifying hadron structure. This interdisciplinary research connects topics in the fields of nuclear, heavy-ion, and (nuclear) astro (particle) physics, linking, for example, terrestrial data to constraints on neutron star structure. A phased roadmap with SIS100 accelerator start-up and envisaged detector upgrades will yield precision cross sections, transition form factors, in-medium spectral functions, and validated theory inputs. Synergies with external programmes at international accelerator facilities worldwide are anticipated. The programme is expected to deliver decisive advances in our understanding of non-perturbative (strong) QCD and astrophysics, and high-rate detector and data-science technology.

We present constraints on the normal branch of the Dvali-Gabadadze-Porrati (nDGP) braneworld gravity model from the abundance of massive galaxy clusters. On scales below the nDGP crossover scale $r_{\rm c}$, the nDGP model features an effective gravity-like fifth force that alters the growth of structure, leading to an enhancement of the halo mass function (HMF) on cluster scales. The enhanced cluster abundance allows for constraints on the nDGP model using cluster samples. We employ the SPT cluster sample, selected through the thermal Sunyaev-Zel'dovich effect (tSZE) with the South Pole Telescope (SPT) and with mass calibration using weak-lensing data from the Dark Energy Survey (DES) and the Hubble Space Telescope (HST). The cluster sample contains 1,005 clusters with redshifts $0.25 < z < 1.78$, which are confirmed with the Multi-Component Matched Filter (MCMF) algorithm using optical and near-infrared data. Weak-lensing data from DES and HST enable a robust mass measurement of the cluster sample. We use DES Year 3 data for 688 clusters with redshifts $z < 0.95$, and HST data for 39 clusters with redshifts $ 0.6 < z <1.7$. We account for the enhancement in the HMF through a semi-analytic correction factor to the $νΛ$CDM HMF derived from the spherical collapse model in the nDGP model. We then further calibrate this model using $N$-body simulations. In addition, for the first time, we analyze the primary cosmic microwave background (CMB) temperature and polarization anisotropy measurements from Planck PR4 within the nDGP model. We obtain a competitive constraint from the joint analysis of the SPT cluster abundance with the Planck PR4 data, and report an upper bound of $1/\sqrt{H_0r_{\rm c}}< 1.41$ at $95\%$ when assuming a cosmology with massive neutrinos.

Context. Our picture of galaxy evolution currently assumes that galaxies spend their life on the star formation main sequence (SFMS) until they are eventually quenched. However, recent observations show indications that the full picture might be more complicated. Aims. We reveal typical in-situ star formation histories and their relations to large-scale environment as well as gas accretion across cosmic time. We further discuss systematic imprints on stellar masses, ages, and metallicities. Methods. We follow the evolution of central galaxies in the highest-resolution box of the MAGNETICUM PATHFINDER cosmological hydrodynamical simulations and classify their evolution scenarios with respect to the SFMS. Results. We find that a major fraction of the galaxies undergoes long-term cycles of quenching and rejuvenation on gigayear timescales. This expands the framework of galaxy evolution from a secular evolution to a sequence of multiple active and passive phases. Only 14% of field galaxies on the SFMS at z ≍ 0 actually evolved along the scaling relation, while the bulk of star-forming galaxies in the local Universe have undergone cycles of quenching and rejuvenation. In this work we describe the statistics of these galaxy evolution modes and how this impacts their mean stellar masses, ages, and metallicities today. We further explore possible explanations and find that the geometry of gas accretion at the halo outskirts shows a strong correlation with the star formation rate evolution, while the density parameter as a tracer of environment shows no significant correlation. A derivation of star formation rates from gas accretion with simple assumptions only works reasonably well in the high-redshift universe, where accreted gas is quickly converted into stars. Conclusions. We conclude that an evolution scenario consistently on the main sequence is the exception, when regarding galaxies on the main sequence at lower redshifts. Galaxies with rejuvenation cycles can be distinguished well from main-sequence-evolved galaxies, both in their halo accretion modes and in their features at z ≍ 0.

Aims. Hyperluminous infrared galaxies (HyLIRGs; star-formation rates of up to ≍1000 M_⊙ yr⁻¹) ─ while rare ─ provide crucial long-lever-arm constraints on galaxy evolution. H-ATLAS J084933.4+021443, a z = 2.41 binary HyLIRG (galaxies 'W' and 'T') with at least two additional luminous companion galaxies ('C' and 'M'), is thus an optimal test ground for studies of star formation and galaxy evolution during 'cosmic noon'. Methods. We have used ALMA to obtain resolved imaging and kinematics of atomic and molecular emission lines, and rest-frame 340 to 1160 GHz continuum emission, for the galaxies W, T, M, and C. Results. All four galaxies are spatially resolved in CO J:7─6, [C I] 2─1, H₂O, and the millimetre (mm) to sub-millimetre continuum, using circular apertures of <inline-formula> ∼0.″3 <mml:math> <mml:mrow> <mml:mo>∼</mml:mo> <mml:mn>0</mml:mn> <mml:mover> <mml:mo>.</mml:mo> <mml:mo>″</mml:mo> </mml:mover> <mml:mn>3</mml:mn> </mml:mrow> </mml:math> </inline-formula> (2.5 kpc) in radius. Rotation-dominated gas kinematics are confirmed in W and T. The gas and continuum emission of galaxy T are extended along its kinematic minor axis, attributable to spatial lensing magnification. Spatially resolved sub-millimetre spectral energy distributions (SEDs) reveal that galaxy W is well fitted with greybody emission from dust at a single temperature over its full extent, despite hosting a powerful active galactic nucleus, while galaxy T requires an additional component of hotter nuclear dust and additional sources of emission in the millimetre. We confirm that [C I] J:2─1 can be used as a tracer of warm/dense molecular gas in extreme systems, though the [C I] J:2─1/CO J:7─6 luminosity ratio increases sub-linearly. We obtain an exquisite resolved (2.5-kpc-scale) Schmidt-Kennicutt (SK) relationship for galaxies W and T, using both cold and warm/dense molecular gas. Gas exhaustion timescales for all apertures in W (T) are ∼50─100 Myr (∼100─500 Myr). Both W and T follow a resolved SK relationship with a power-law index of n ∼ 1.7, significantly steeper than the n ∼ 1 found previously via cold molecular gas in nearby 'normal' star-forming galaxies.

Ultracompact X-ray binaries (UCXBs) are a subclass of low-mass X-ray binaries characterized by tight orbits and degenerate donors, which pose significant challenges to our understanding of their formation. Recent discoveries of black hole (BH) candidates with main-sequence or red giant companions suggest that BH─white dwarf (BH─WD) binaries are common in the Galactic field. Motivated by these observations and the fact that most massive stars are born in triples, we show that wide BH─WD systems can naturally form UCXBs through the eccentric Kozai─Lidov (EKL) mechanism. Notably, EKL-driven eccentricity excitations combined with gravitational wave (GW) emission and WD dynamical tides can effectively shrink and circularize the orbit, leading to mass-transferring BH─WD binaries. These systems represent promising multimessenger sources in both X-ray and GW observations. Specifically, we predict that the wide triple channel can produce ∼3─27 (∼1─5) detectable UCXBs in the Milky Way (Andromeda galaxy), including ∼1 system observable by the mHz GW detection of LISA. If the final WD mass can reach sufficiently small values, this channel could contribute up to ∼10³ UCXBs in the Galaxy. Furthermore, the identification of tertiary companions in observed UCXBs would provide direct evidence for this formation pathway and yield unique insights into their dynamical origins.

We analyze entanglement generated by the Schwinger effect using a mode-by-mode formalism for scalar and spinor QED in constant backgrounds. Starting from thermal initial states, we derive compact, closed-form results for bipartite entanglement between particle-antiparticle partners in terms of the Bogoliubov coefficients. For bosons, thermal fluctuations enhance production but suppress quantum correlations: the logarithmic negativity is nonzero only below a (mode-dependent) critical temperature $T_c$. At fixed $T$, entanglement appears only above a critical field $E_{\text{crit,entang}}$. For fermions, we observe a qualitatively different pattern: at finite $T$ entanglement exists only within a finite window $E_{\text{min}} < E < E_{\text{max}}$, with a temperature-independent optimal field strength $E_{*}$ that maximizes the logarithmic negativity. Entanglement is vanishing above $T_{\text{max}}=ω/\text{arcsinh}(1)$. We give quantitative estimates for analog experiments, where our entanglement criteria convert directly into concrete temperature and electric field constraints. These findings identify realistic regimes where the quantum character of Schwinger physics may be tested in the laboratory.

The hidden-charm pentaquark states <inline-formula><mml:math><mml:mrow><mml:msub><mml:mrow><mml:mi>P</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi><mml:mover><mml:mrow><mml:mi>c</mml:mi></mml:mrow><mml:mrow><mml:mo>̄</mml:mo></mml:mrow></mml:mover></mml:mrow></mml:msub><mml:msup><mml:mrow><mml:mo>(</mml:mo><mml:mn>4312</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math></inline-formula>, <inline-formula><mml:math><mml:mrow><mml:msub><mml:mrow><mml:mi>P</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi><mml:mover><mml:mrow><mml:mi>c</mml:mi></mml:mrow><mml:mrow><mml:mo>̄</mml:mo></mml:mrow></mml:mover></mml:mrow></mml:msub><mml:msup><mml:mrow><mml:mo>(</mml:mo><mml:mn>4380</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math></inline-formula>, <inline-formula><mml:math><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mi>c</mml:mi><mml:mover><mml:mi>c</mml:mi><mml:mo>̄</mml:mo></mml:mover></mml:mrow></mml:msub><mml:msup><mml:mrow><mml:mo>(</mml:mo><mml:mn>4440</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mo>+</mml:mo></mml:msup></mml:math></inline-formula>, and <inline-formula><mml:math><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mi>c</mml:mi><mml:mover><mml:mi>c</mml:mi><mml:mo>̄</mml:mo></mml:mover></mml:mrow></mml:msub><mml:msup><mml:mrow><mml:mo>(</mml:mo><mml:mn>4457</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mo>+</mml:mo></mml:msup></mml:math></inline-formula>, all with isospin <inline-formula><mml:math><mml:mi>I</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn></mml:math></inline-formula>, were discovered by the LHCb Collaboration in the decay process <inline-formula><mml:math><mml:mrow><mml:msubsup><mml:mrow><mml:mi>Λ</mml:mi></mml:mrow><mml:mrow><mml:mi>b</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msubsup><mml:mo>→</mml:mo><mml:mi>J</mml:mi><mml:mo>/</mml:mo><mml:mi>ψ</mml:mi><mml:mi>p</mml:mi><mml:msup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mo>-</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math></inline-formula>. Although their quantum numbers remain undetermined, these states have generated significant theoretical interest. We analyze their spectrum and decay patterns—including those of their spin partners—within the Born-Oppenheimer (BO) effective field theory (BOEFT), a framework grounded in QCD. At leading order in BOEFT, we identify these pentaquark states as bound states in BO potentials that exhibit at short distance a repulsive octet behavior and a nonperturbative shift due to the adjoint baryons masses, while asymptotically approaching the <inline-formula><mml:math><mml:msub><mml:mi>Σ</mml:mi><mml:mi>c</mml:mi></mml:msub><mml:mover><mml:mi>D</mml:mi><mml:mo>̄</mml:mo></mml:mover></mml:math></inline-formula> threshold. We further incorporate <inline-formula><mml:math><mml:mi>O</mml:mi><mml:mo>(</mml:mo><mml:mn>1</mml:mn><mml:mo>/</mml:mo><mml:msub><mml:mi>m</mml:mi><mml:mi>Q</mml:mi></mml:msub><mml:mo>)</mml:mo></mml:math></inline-formula> spin-dependent corrections to compute pentaquark multiplet spin splittings. Based on the spectrum, semi-inclusive decay widths to <inline-formula><mml:math><mml:mi>J</mml:mi><mml:mo>/</mml:mo><mml:mi>ψ</mml:mi></mml:math></inline-formula> and <inline-formula><mml:math><mml:msub><mml:mi>η</mml:mi><mml:mi>c</mml:mi></mml:msub></mml:math></inline-formula>, and the decay width ratios to <inline-formula><mml:math><mml:msub><mml:mi>Λ</mml:mi><mml:mi>c</mml:mi></mml:msub><mml:mover><mml:mi>D</mml:mi><mml:mo>̄</mml:mo></mml:mover></mml:math></inline-formula> and <inline-formula><mml:math><mml:msub><mml:mi>Λ</mml:mi><mml:mi>c</mml:mi></mml:msub><mml:msup><mml:mover><mml:mi>D</mml:mi><mml:mo>̄</mml:mo></mml:mover><mml:mo>*</mml:mo></mml:msup></mml:math></inline-formula>, we provide the first theoretical predictions for the adjoint baryon masses, which can be confirmed by future lattice QCD studies. Moreover, our analysis supports the quantum number assignments: <inline-formula><mml:math><mml:msup><mml:mi>J</mml:mi><mml:mi>P</mml:mi></mml:msup><mml:mo>=</mml:mo><mml:mo>(</mml:mo><mml:mn>1</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn><mml:msup><mml:mo>)</mml:mo><mml:mo>-</mml:mo></mml:msup></mml:math></inline-formula> for <inline-formula><mml:math><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mi>c</mml:mi><mml:mover><mml:mi>c</mml:mi><mml:mo>̄</mml:mo></mml:mover></mml:mrow></mml:msub><mml:msup><mml:mrow><mml:mo>(</mml:mo><mml:mn>4312</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mo>+</mml:mo></mml:msup></mml:math></inline-formula>, <inline-formula><mml:math><mml:mo>(</mml:mo><mml:mn>3</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn><mml:msup><mml:mo>)</mml:mo><mml:mo>-</mml:mo></mml:msup></mml:math></inline-formula> for <inline-formula><mml:math><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mi>c</mml:mi><mml:mover><mml:mi>c</mml:mi><mml:mo>̄</mml:mo></mml:mover></mml:mrow></mml:msub><mml:msup><mml:mrow><mml:mo>(</mml:mo><mml:mn>4380</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mo>+</mml:mo></mml:msup></mml:math></inline-formula>, <inline-formula><mml:math><mml:mo>(</mml:mo><mml:mn>1</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn><mml:msup><mml:mo>)</mml:mo><mml:mo>-</mml:mo></mml:msup></mml:math></inline-formula> for <inline-formula><mml:math><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mi>c</mml:mi><mml:mover><mml:mi>c</mml:mi><mml:mo>̄</mml:mo></mml:mover></mml:mrow></mml:msub><mml:msup><mml:mrow><mml:mo>(</mml:mo><mml:mn>4457</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mo>+</mml:mo></mml:msup></mml:math></inline-formula>, and <inline-formula><mml:math><mml:mo>(</mml:mo><mml:mn>3</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn><mml:msup><mml:mo>)</mml:mo><mml:mo>-</mml:mo></mml:msup></mml:math></inline-formula> for <inline-formula><mml:math><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mi>c</mml:mi><mml:mover><mml:mi>c</mml:mi><mml:mo>̄</mml:mo></mml:mover></mml:mrow></mml:msub><mml:msup><mml:mrow><mml:mo>(</mml:mo><mml:mn>4440</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mo>+</mml:mo></mml:msup></mml:math></inline-formula>. We also present results for the lowest bottom pentaquarks.

We present cosmological constraints from eight strongly lensed quasars (hereafter, the TDCOSMO-2025 sample). Building on previous work, our analysis incorporated new deflector stellar velocity dispersions measured from spectra obtained with the James Webb Space Telescope (JWST), the Keck Telescopes, and the Very Large Telescope (VLT), utilizing improved methods. We used integrated JWST stellar kinematics for five lenses, VLT-MUSE for 2, and resolved kinematics from Keck and JWST for RX J1131−1231. We also considered two samples of non-time-delay lenses: 11 from the Sloan Lens ACS (SLACS) sample with Keck-KCWI resolved kinematics; and four from the Strong Lenses in the Legacy Survey (SL2S) sample. We improved our analysis of line-of-sight effects, the surface brightness profile of the lens galaxies, and orbital anisotropy, and corrected for projection effects in the dynamics. Our uncertainties are maximally conservative by accounting for the mass-sheet degeneracy in the deflectors' mass density profiles. The analysis was blinded to prevent experimenter bias. Our primary result is based on the TDCOSMO-2025 sample, in combination with Ω_m constraints from the Pantheon+ Type Ia supernovae (SN) dataset. In the flat Λ cold dark matter (CDM), we find <inline-formula> H₀ = 71.6^+3.9_−3.3 km s⁻¹ Mpc⁻¹ <mml:math> <mml:mrow> <mml:msub> <mml:mi>H</mml:mi> <mml:mn>0</mml:mn> </mml:msub> <mml:mo>=</mml:mo> <mml:mrow> <mml:mn>71</mml:mn> <mml:mo>.</mml:mo> <mml:msubsup> <mml:mn>6</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>3.3</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>3.9</mml:mn> </mml:mrow> </mml:msubsup> </mml:mrow> <mml:mrow> <mml:mspace></mml:mspace> <mml:mi>km</mml:mi> <mml:mspace></mml:mspace> <mml:msup> <mml:mrow> <mml:mi>s</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> <mml:mspace></mml:mspace> <mml:msup> <mml:mrow> <mml:mi>Mpc</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:mrow> </mml:math> </inline-formula>. The SLACS and SL2S samples are in excellent agreement with the TDCOSMO-2025 sample, improving the precision on H₀ in flat ΛCDM to 4.6%. Using the Dark Energy Survey SN Year-5 dataset (DES-SN5YR) or DESI-DR2 baryonic acoustic oscillations (BAO) likelihoods instead of Pantheon+ yields very similar results. We also present constraints in the open ΛCDM, wCDM, w₀w_aCDM, and w_ϕCDM cosmologies. The TDCOSMO H₀ inference is robust and consistent across all presented cosmological models, and our cosmological constraints in them agree with those from the BAO and SN.

We study the cosmological gravitational particle production (CGPP) of spin-3/2 particles during and after cosmic inflation, and map the parameter space that can realize the observed dark matter density in stable spin-3/2 particles. Originally formulated by Rarita and Schwinger, the relativistic theory of a massive spin-3/2 field later found a home in supergravity as the superpartner of the graviton, and in nuclear physics as baryonic resonances and nuclear isotopes. We study a minimal model realization, namely a free massive spin-3/2 field minimally coupled to gravity, and adopt the name raritron for this field. We demonstrate that CGPP of raritrons crucially depends on the hierarchy between the raritron mass $m_{3/2}$ and the Hubble parameter at the end of inflation $H_e$, with high-mass and low-mass cases distinguished by the evolution of the sound speed $c_s$ of the longitudinal (helicity-1/2) mode, which is approximately unity at all times for heavy (relative to Hubble) raritrons and can become small or vanish for lighter raritrons, leading to a dramatic enhancement of production of high momentum particles in the latter case. Assuming the raritrons are stable, this leads to a wide parameter space to produce the observed dark matter density. Finally, we consider a time-dependent raritron mass, which can be chosen to remove the vanishing sound speed of the longitudinal mode, but which nonetheless enhances the production relative to the constant high-mass case, and in particular does not necessarily tame the high momentum tail of the spectrum. We perform our calculations using the Bogoliubov formalism and compare, when applicable, to the Boltzmann formalism.

We present the discovery of EP250827b/SN 2025wkm, an X-ray Flash (XRF) discovered by the Einstein Probe (EP), accompanied by a broad-line Type Ic supernova (SN Ic-BL) at $z = 0.1194$. EP250827b possesses a prompt X-ray luminosity of $\sim 10^{45} \, \rm{erg \, s^{-1}}$, lasts over 1000 seconds, and has a peak energy $E_{\rm{p}} < 1.5$ keV at 90% confidence. SN 2025wkm possesses a double-peaked light curve (LC), though its bolometric luminosity plateaus after its initial peak for $\sim 20$ days, giving evidence that a central engine is injecting additional energy into the explosion. Its spectrum transitions from a blue to red continuum with clear blueshifted Fe II and Si II broad absorption features, allowing for a SN Ic-BL classification. We do not detect any transient radio emission and rule out the existence of an on-axis, energetic jet $\gtrsim 10^{50}~$erg. In the model we invoke, the collapse gives rise to a long-lived magnetar, potentially surrounded by an accretion disk. Magnetically-driven winds from the magnetar and the disk mix together, and break out with a velocity $\sim 0.35c$ from an extended circumstellar medium with radius $\sim 10^{13}$ cm, generating X-ray breakout emission through free-free processes. The disk outflows and magnetar winds power blackbody emission as they cool, producing the first peak in the SN LC. The spin-down luminosity of the magnetar in combination with the radioactive decay of $^{56}$Ni produces the late-time SN LC. We end by discussing the landscape of XRF-SNe within the context of EP's recent discoveries.

Neutrinos are the most abundant fundamental matter particles in the Universe and play a crucial part in particle physics and cosmology. Neutrino oscillation, discovered about 25 years ago, shows that the three known species mix with each other. Anomalous results from reactor and radioactive-source experiments¹ suggest a possible fourth neutrino state, the sterile neutrino, which does not interact through the weak force. The Karlsruhe Tritium Neutrino (KATRIN) experiment², primarily designed to measure the neutrino mass using tritium β-decay, also searches for sterile neutrinos suggested by these anomalies. A sterile-neutrino signal would appear as a distortion in the β-decay energy spectrum, characterized by a discontinuity in curvature (kink) related to the sterile-neutrino mass. This signature, which depends only on the shape of the spectrum rather than its absolute normalization, offers a robust, complementary approach to reactor experiments. Here we report the analysis of the energy spectrum of 36 million tritium β-decay electrons recorded in 259 measurement days within the last 40 eV below the endpoint. The results exclude a substantial part of the parameter space suggested by the gallium anomaly and challenge the Neutrino-4 claim. Together with other neutrino-disappearance experiments, KATRIN probes sterile-to-active mass splittings from a fraction of an eV² to several hundred eV², excluding light sterile neutrinos with mixing angles above a few per cent.

GRB 250702B was the longest gamma-ray burst ever detected, with a duration that challenges standard collapsar models and suggests an exotic progenitor. We collected a rich set of optical and infrared follow-up observations of its rapidly fading afterglow using a suite of telescopes including the W. M. Keck Observatory, the Gemini telescopes, the Magellan Baade Telescope, the Victor M. Blanco 4 m telescope, and the Fraunhofer Telescope at Wendelstein Observatory. Our analysis reveals that the afterglow emission is well described by forward shock emission from a highly obscured relativistic jet. Deep photometric observations of the host galaxy reveal a massive (10^10.66 M_⊙), dusty, and extremely asymmetric system that is consistent with two galaxies undergoing a major merger. The galactocentric offset, host galaxy properties, and jet characteristics disfavor a jetted tidal disruption event (TDE) around a supermassive black hole but do not definitively distinguish between competing progenitor scenarios. We find that the afterglow and host are consistent with a range of progenitors, including an atypical collapsar, a merger between a helium star and a stellar-mass black hole, the disruption of a star by a stellar-mass compact object (micro-TDE), and the tidal disruption of a star by an off-nuclear intermediate-mass black hole.

Ground-based high-resolution spectroscopy has identified various chemical species in the atmospheres of ultra-hot Jupiters, including neutral and ionized metals, providing key insights into planet formation through refractory element abundances. We observed the dayside thermal emission spectrum of the UHJ HAT-P-70b using the high-resolution spectrographs CARMENES and PEPSI. Through cross-correlation analysis, we detect emission signals of Al i, AlH, Ca ii, Cr i, Fe i, Fe ii, Mg i, Mn i, and Ti i, marking the first detection of Al i and AlH in an exoplanetary atmosphere. Tentative signals of C i, Ca i, Na i, NaH, and Ni i are also identified. These detections enable atmospheric retrievals to constrain the thermal profile and elemental abundances of the planet's dayside hemisphere. The retrieved temperature-pressure profile reveals a strong thermal inversion. The chemical free retrieval yields a metallicity of [Fe/H] = 0.38(+0.74/-1.11), while the chemical equilibrium retrieval gives [Fe/H] = 0.23(+1.08/-0.98), both consistent with solar metallicity. We also tentatively find an enhanced abundance of Ni, possibly due to the accretion of Ni-rich planetesimals during formation. On the other hand, elements with condensation temperatures above 1400 K (e.g., Ca, Ti, and V) appear slightly depleted, which may be caused by nightside cold trapping. However, Al, with the highest condensation temperature at 1653K, displays a solar like abundance, which might reflect the formation-related enrichment of Al. Our retrieval indicates extremely high volume mixing ratios of metal ions (Fe ii and Ca ii), which are significantly inconsistent with predictions from chemical equilibrium models. This disequilibrium suggests that the atmosphere is likely undergoing significant hydrodynamic escaping, which enhances the atmospheric density at high altitudes where the ionic lines are formed.

The dynamics of phase-separated interfaces shape the behavior of both passive and active condensates. While surface tension in equilibrium systems minimizes interface length, nonequilibrium fluxes can destabilize flat or constantly curved interfaces, giving rise to complex interface morphologies. Starting from a minimal model that couples a conserved, phase-separating species to a self-generated chemical field, we identify the conditions under which interfacial instabilities may emerge. Specifically, we show that nonreciprocal chemotactic interactions induce two distinct types of instabilities: a stationary (nonoscillatory) instability that promotes interface deformations and an oscillatory instability that can give rise to persistent capillary waves propagating along the boundaries of phase-separated domains. To characterize these phenomena, we develop a perturbative framework that predicts the onset, wavelength, and velocity of capillary waves, and quantitatively validate these predictions through numerical simulations. Beyond the linear regime, our simulations reveal that capillary waves undergo a secondary instability, leading to either stationary or dynamically evolving superpositions of different wave modes. Finally, we investigate whether capillary waves can facilitate directed mass transport, either along phase boundaries (conveyor belts) or through self-sustained liquid gears crawling along a solid wall. Taken together, our results establish a general framework for interfacial dynamics in active phase-separating systems and suggest strategies for controlling mass transport in soft matter and biological condensates.

Intracellular protein patterns govern essential cellular functions by dynamically redistributing proteins between membrane-bound and cytosolic states, conserving their total numbers. This review presents a theoretical framework for understanding such patterns based on mass-conserving reaction--diffusion systems. The emergence, selection, and evolution of patterns are analyzed in terms of mass redistribution and interface motion, resulting in mesoscale laws of coarsening and wavelength selection. A geometric phase-space perspective provides a conceptual tool to link local reactive equilibria with global pattern dynamics through conserved mass fluxes. The Min protein system of \emph{Escherichia coli} provides a paradigmatic example, enabling direct comparison between theory and experiment. Successive model refinements capture both the robustness of pattern formation and the diversity of dynamic regimes observed \emph{in vivo} and \emph{in vitro}. The Min system thus illustrates how to extract predictive, multiscale theory from biochemical detail, providing a foundation for understanding pattern formation in more complex and synthetic systems.

We present COSMOS2025, the COSMOS-Web catalog of photometry, morphology, photometric redshifts, and physical parameters for more than 700 000 galaxies in the Cosmic Evolution Survey (COSMOS) field. This catalog is based on our James Webb Space Telescope 255 h COSMOS-Web program, which provides deep near-infrared imaging in four NIRCam (F115W, F150W, F277W, F444W) and one MIRI (F770W) filter over the central ~0.54 deg² (~0.2 deg² for MIRI) in COSMOS. These data are combined with ground- and space-based data to derive photometric measurements of NIRCam-detected sources using both fixed-aperture photometry (on the space-based bands) and a profile-fitting technique on all 37 bands spanning 0.3 μm to 8 μm. We provide morphology for all sources from complementary techniques including profile fitting and machine-learning classification. We derive photometric redshifts, physical parameters, and non-parametric star formation histories from spectral energy distribution (SED) fitting. The catalog has been extensively validated against previous COSMOS catalogs and other surveys. Photometric redshift accuracy measured using spectroscopically confirmed galaxies out to z ~ 9 reaches σ_MAD = 0.012 at m_F444W < 28 and remains at σ_MAD ≲ 0.03 as a function of magnitude, color, and galaxy type. This represents a factor of ~2 improvement at 26 AB mag compared to COSMOS2020. The catalog is approximately 80% complete at log(M_⋆/M_⊙) ~ 9 at z ~ 10 and at log(M_⋆/M_⊙) ~ 7 at z ~ 0.2, representing a gain of 1 dex compared to COSMOS2020. COSMOS2025 represents the definitive COSMOS-Web catalog. It is provided with complete documentation, together with redshift probability distributions, and it is ready for scientific exploitation today.

Understanding the effect of system size on the applicability of the hydrodynamic description in heavy-ion physics remains unclear. Recent measurements of OO collisions at the LHC offer a new opportunity to refine our understanding of collectivity because of their intermediate size relative to heavy-ion and small-system collisions, as well as the relatively good control over their initial state. We use the CoMBolt-ITA hybrid model to describe recent OO measurements at the LHC. The model employs TrENTo for the initial state. A combination of the pre-equilibration and hydrodynamized medium stages is modeled consistently by CoMBolt-ITA, which evolves the Boltzmann distribution of massless collective excitations. The afterburner stage is included by employing UrQMD. Using this approach, we test whether the system lies in the regime where its spatial size approaches the mean free path, corresponding to low opacity, or in the opposite limit, where its size exceeds the mean free path sufficiently to enter the fluid-like evolution regime with high opacity. We find that, in light of the data-model comparison and considering the current status of the model, OO collisions with centralities larger than $60\%$ gradually leave the domain of fluid-like evolution.

We investigate the phases of a strongly coupled QCD-like theory at finite baryon chemical potential using s-confining supersymmetric QCD deformed by anomaly-mediated supersymmetry breaking. Focusing on the case of three colors and four flavors, we identify novel phases including spontaneous breaking of baryon number and/or parity. Both first-order and second-order phase transitions are observed as the baryon chemical potential is varied. These findings may offer insights into possible phases of real QCD at intermediate baryon densities.

Collective neutrino flavor conversions in core-collapse supernovae begin with instabilities, initially triggered when the dominant <inline-formula><mml:math><mml:msub><mml:mi>ν</mml:mi><mml:mi>e</mml:mi></mml:msub></mml:math></inline-formula> outflow concurs with a small antineutrino flux of opposite lepton number, with <inline-formula><mml:math><mml:msub><mml:mover><mml:mi>ν</mml:mi><mml:mo>̄</mml:mo></mml:mover><mml:mi>e</mml:mi></mml:msub></mml:math></inline-formula> dominating over <inline-formula><mml:math><mml:msub><mml:mover><mml:mi>ν</mml:mi><mml:mo>̄</mml:mo></mml:mover><mml:mi>μ</mml:mi></mml:msub></mml:math></inline-formula>. When these "flipped" neutrinos emerge in the energy-integrated angular distribution (angular crossing), they initiate a fast instability. However, before such conditions arise, spectral crossings typically appear within 20 ms of collapse, i.e., local spectral excesses of <inline-formula><mml:math><mml:msub><mml:mover><mml:mi>ν</mml:mi><mml:mo>̄</mml:mo></mml:mover><mml:mi>e</mml:mi></mml:msub></mml:math></inline-formula> over <inline-formula><mml:math><mml:msub><mml:mover><mml:mi>ν</mml:mi><mml:mo>̄</mml:mo></mml:mover><mml:mi>μ</mml:mi></mml:msub></mml:math></inline-formula> along some direction. Therefore, postprocessing supernova simulations cannot consistently capture later fast instabilities because the early slow ones have already altered the conditions.

Context. We present simulations of a massive young star cluster using the codes NBODY6++GPU and MOCCA. The cluster is initially more compact than previously published models. It contains one million stars and has a total mass of 5.86 × 10⁵ M_⊙ and a half-mass radius of 0.1 pc. Aims. We analyzed the formation and growth of a very massive star (VMS) through successive stellar collisions and investigated the subsequent formation of an intermediate-mass black hole (IMBH) in the core of a dense star cluster. Methods. We used direct N-body and Monte Carlo simulations that incorporated updated stellar evolution prescriptions for single and binary stellar evolution (SSE and BSE) tailored to massive stars and VMSs. These include revised treatments of stellar radii, rejuvenation, and mass loss during collisions. While the prescriptions represent reasonable extrapolations into the VMS regime, the internal structure and thermal state of VMSs that formed through stellar collisions remain uncertain, and future work may require further refinement. Results. Runaway stellar collisions in the cluster core produce a VMS that exceeds 5 × 10⁴ M_⊙ within 5 Myr that subsequently collapses into an IMBH. We stress that further work on stellar astrophysics is needed, particularly in the context of VMS formation. The VMS formation currently represents strong uncertainties. Conclusions. Our model suggests that dense stellar environments may enable the formation of VMSs and massive black hole seeds through runaway stellar collisions. These results provide a potential pathway for early black hole growth in star clusters and offer a theoretical context for interpreting recent observations with the James Webb Space Telescope of young compact clusters at high redshift.

Mock galaxy catalogues are often constructed from dark-matter-only simulations based on the galaxy-halo connection. Although modern mocks can reproduce galaxy clustering to some extent, the absence of baryons affects the spatial and kinematic distributions of galaxies in ways that remain insufficiently quantified. We compare the positions and velocities of satellite galaxies in the MTNG hydrodynamic simulation with those in its dark-matter-only counterpart, assessing how baryonic effects influence galaxy clustering and contrasting them with the impact of galaxy selection, i.e. the dependence of clustering on sample definition. Using merger trees from both runs, we track satellite subhaloes until they become centrals, allowing us to match systems even when their z=0 positions differ. We then compute positional and velocity offsets as functions of halo mass and distance from the halo centre, and use these to construct a subhalo catalogue from the dark-matter-only simulation that reproduces the galaxy distribution in the hydrodynamic run. Satellites in the hydrodynamic simulation lie 3-4% closer to halo centres than in the dark-matter-only case, with an offset that is nearly constant with halo mass and increases toward smaller radii. Satellite velocities are also systematically higher in the dark-matter-only run. At scales of 0.1 Mpc/h, these spatial and kinematic differences produce 10-20% variations in clustering amplitude -- corresponding to 1-3$σ$ assuming DESI-like errors -- though the impact decreases at larger scales. These baryonic effects are relevant for cosmological and lensing analyses and should be accounted for when building high-fidelity mocks. However, they remain smaller than the differences introduced by galaxy selection, which thus represents the dominant source of uncertainty when constructing mocks based on observable quantities.

Context. Accurately accounting for the Active Galactic Nucleus (AGN) phase in galaxy evolution requires a large, clean AGN sample. This is now possible with SRG/eROSITA, which completed its first all-sky X-ray survey (eRASS1) on June 12, 2020. The public Data Release 1 (DR1, Jan 31, 2024) includes 930,203 sources from the western Galactic hemisphere. Aims. The data enable the selection of a large AGN sample and the discovery of rare sources. However, scientific return depends on accurate characterisation of the X-ray emitters, requiring high-quality multi-wavelength data. This paper presents the identification and classification of optical and infrared counterparts to eRASS1 sources. Methods. Counterparts to eRASS1 X-ray point sources were identified using Gaia DR3, CatWISE2020, and Legacy Survey DR10 (LS10) with the Bayesian NWAY algorithm and trained priors. Sources were classified as Galactic or extragalactic via a machine-learning model combining optical/IR and X-ray properties, trained on a reference sample. For extragalactic LS10 sources, photometric redshifts were computed using CIRCLEZ. Results. Within the LS10 footprint, all 656,614 eROSITA/DR1 sources have at least one possible optical counterpart; ∼570 000 are extragalactic and likely AGN. Half are new detections compared to AllWISE, Gaia, and Quaia AGN catalogues. Gaia and CatWISE2020 counterparts are less reliable, due to the survey's shallowness and the limited amount of features available to assess the probability of being an X-ray emitter. In the Galactic plane, where the overdensity of stellar sources also increases the chance of associations, using conservative reliability cuts, we identified approximately 18 000 Gaia and 55 000 CatWISE2020 extragalactic sources. Conclusions. We have released three high-quality counterpart catalogues ─ plus the training and validation sets ─ as a benchmark for the field. These datasets have many applications, but in particular, they empower researchers to build AGN samples tailored for completeness and purity, accelerating the hunt for the Universe's most energetic engines.

DESI DR2 data have been widely interpreted as evidence for late-time evolving dark energy (DE) with an apparent phantom crossing. Here we investigate an alternative explanation, based on early-Universe physics. If dark acoustic oscillations (DAO) are close in scale to baryon acoustic oscillations (BAO), they can bias the extraction of the BAO scale from the peak in the galaxy correlation function. This leads to an apparent shift in the inferred distance if the superposition of BAO and DAO features is misinterpreted as being due to BAO only. Taking this shift into account, we find that a DAO with percent-level amplitude can reconcile DESI DR2 with Planck 2018 as well as Pantheon+ supernovae data, with fit improvement at a similar level as compared to evolving DE. Notably, a DAO feature with the required properties has been predicted in a previously proposed scenario that resolves the Hubble tension via a pre-recombination decoupling of dark matter and dark radiation (DRMD). The presence of a DAO feature close to the BAO peak can be scrutinized with future full-shape galaxy clustering data from DESI and Euclid.

We investigate dynamical symmetry breaking in a class of chiral gauge theories containing the Georgi-Glashow model. These theories feature a gauge sector and two fermion species that transform in the two-index antisymmetric and antifundamental representations with different multiplicities. Using the effective action formalism and the functional renormalization group, we derive the flow of four-fermion interactions that encode their resonant structure and information about bound-state formation. Generalizing the theories to multiple generations, we make contact with the loss of asymptotic freedom and dissect the boundary of a conjectured conformal window. Our results show that, while most of the theory space displays a dominant color-breaking condensate, there exists a strongly coupled regime where the lowest-laying mechanisms fail and more intricate dynamics are expected to arise. This analysis provides a first step toward the infrared behavior of chiral gauge theories with functional methods.

Context. Dust dynamics plays a critical role in astrophysical processes and has been modeled in hydrodynamical simulations using various approaches. Among particle-based methods like Smoothed Particle Hydrodynamics (SPH), the One-Fluid model has proven to be highly effective for simulating gas-dust mixtures. Aims. This study presents the implementation of the One-Fluid model in OpenGadget3, introducing improvements to the original formulation. These enhancements include time-dependent artificial viscosity and conductivity, as well as a novel treatment of dust diffusion using a pressure-like term. Methods. The improved model is tested using a suite of dust dynamics benchmark problems: DUSTYBOX, DUSTYWAVE, and DUSTYSHOCK, with the latter extended to multidimensional scenarios, as well as a dusty Sedov-Taylor blast wave. Additional tests include simulations of Cold Keplerian Disks, dusty protoplanetary disks, and Kelvin─Helmholtz instabilities to evaluate the model's robustness in more complex flows. Results. The implementation successfully passes all standard benchmark tests. It demonstrates stability and accuracy in both simple and complex simulations. The new diffusion term improves the handling of flows with large dust-to-gas ratios and low drag coefficients, although limitations of the One-Fluid model in these regimes remain. Conclusions. The enhanced One-Fluid model is a reliable and robust tool for simulating dust dynamics in OpenGadget3. While it retains some limitations inherent to the original formulation, the introduced improvements expand its applicability and address some challenges in gas-dust dynamics.

Blue supergiant distances of nearby galaxies obtained with the flux-weighted gravity─luminosity relationship are used for a measurement of the zero-points of Tully─Fisher relationships at different photometric passbands. The Cousins I band and the infrared WISE bands W1 and W2 are investigated. The results are compared with previous work using Cepheid and tip of the red giant branch distances. No significant differences were encountered. This supports the large values of the Hubble constant greater than 73 km s⁻¹ Mpc⁻¹ found with the Tully─Fisher distance ladder work over the last decade. Applying blue supergiant distances on the I-band Tully─Fisher relation observations yields a Hubble constant H₀ = 76.2 ± 6.2 km s⁻¹ Mpc⁻¹. The large uncertainty is caused by the still relatively small blue supergiant galaxy sample size but will be reduced in future work.

We develop a quadratic-in-Riemann worldline action for a Kerr black hole at infinite spin orders by matching to a proposed tree-level Kerr Compton amplitude, originally obtained from higher-spin QFT considerations. A worldline action is an effective theory, and as such the tree-level matching needs to be corrected by loop effects, including UV counter terms, renormalization, and higher-order matching to general relativity. However, we anticipate that many features of the Wilson coefficients of the proposed tree-level action will remain unchanged even after a loop-level matching. While the worldline action is given in closed form, it contains an infinite number of quadratic-in-Riemann operators $R^2$, even for the same-helicity sector. We argue that in the same-helicity sector the $R^2$ operators have no intrinsic meaning, as they merely remove unwanted terms produced by the linear-in-Riemann operators, which are well-established in the literature. The opposite-helicity sector is somewhat more complicated, it contains both $R^2$ operators that removes unwanted terms, and $R^2$ operators that add new needed terms to the Compton amplitude. We discuss and classify all independent $R^2$ operators that can feature in the worldline action.

We report a laboratory search for ultralight dark photon dark matter using a single-site, two-sensor array of commercial scalar optically pumped magnetometers. In the low-frequency regime where the Earth─ionosphere system acts as an electromagnetic transducer, the expected magnetic signal is a narrow-band triplet of frequencies. This signature consists of a central peak at the dark photon's Compton frequency, accompanied by two sidebands shifted by Earth's sidereal rotation frequency. Because scalar magnetometers measure field magnitude, the observable signal is the projection of the oscillating dark photon magnetic field onto the direction of the large, local geomagnetic field. This preserves the crucial triplet signature in the resulting time series data. Analyzing 10.5 h of continuous data, we construct a six-channel complex data vector by evaluating the discrete-time Fourier transform for both sensors directly at the three physical frequencies of the signal triplet. Assuming complex-Gaussian noise, we develop a likelihood framework to set robust, frequency-resolved upper limits on the kinetic-mixing parameter <inline-formula><mml:math><mml:mrow><mml:mi>ϵ</mml:mi></mml:mrow></mml:math></inline-formula>, which governs the coupling between Standard Model photons and dark photons. Within the mass range <inline-formula><mml:math><mml:mn>4</mml:mn><mml:mo>×</mml:mo><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>-</mml:mo><mml:mn>15</mml:mn></mml:mrow></mml:msup><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>eV</mml:mi><mml:mo>≲</mml:mo><mml:msub><mml:mi>m</mml:mi><mml:msup><mml:mi>A</mml:mi><mml:mo>'</mml:mo></mml:msup></mml:msub><mml:mo>≲</mml:mo><mml:mn>3</mml:mn><mml:mo>×</mml:mo><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>-</mml:mo><mml:mn>14</mml:mn></mml:mrow></mml:msup><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>eV</mml:mi></mml:math></inline-formula>, we obtain the most stringent direct laboratory limits to date on the kinetic-mixing parameter, which are complementary to existing astrophysical bounds, including those inferred from observations of the Leo T dwarf galaxy.

Aims. We study the individual and cumulative impact of stellar feedback on massive black hole (MBH) growth in a simulated low-mass dwarf galaxy. Furthermore, we explore the influence of the MBH's initial mass (10³⁻⁶ M_⊙) on the gas accretion, and whether or not artificially induced gas inflows can 'boost' further gas accretion onto the MBH. Methods. A suite of high-resolution radiation-hydrodynamic simulations called NOCTUA were performed, using the AREPONOCTUA numerical framework. The chemical evolution of the interstellar medium (ISM) was modelled in a time-dependent non-equilibrium way. Two types of stellar feedback were considered: individually traced type II supernova (SNII) explosions, and radiatively transferred (on-the-fly) ionising stellar radiation (ISR) from OB stars. As part of AREPONOCTUA, we develop and apply a novel physically motivated model for MBH gas accretion, taking into account the angular momentum of the gas in the radiatively efficient regime, to estimate the gas accretion rate onto the MBH from its sub-grid accretion disc. Results. Without any stellar feedback, an initial 10⁴ M_⊙ MBH is able to steadily grow over time, roughly doubling its mass after 800 Myr. Surprisingly, the growth of the MBH more than doubles when only ISR feedback is considered, compared to the no stellar feedback run. This is due to the star formation rate (SFR) being highly suppressed (to a similar level or slightly above that when SNII feedback is considered), enabling a higher cumulative net gas inflow onto the MBH from not only the cold neutral and molecular medium phases, but also the unstable and warm neutral medium phases of the ISM. With SNII feedback included, the gas accretion onto the MBH is episodic over time, and is already suppressed by more than an order of magnitude during the first 150 Myr. When combining SNII with ISR feedback, the growth of the MBH remains suppressed due to SNII explosions, but to a lesser extent compared to the SNII-only feedback run, due to a slightly lower SFR, and thus a reduced number of SNII events. Conclusions. We conclude that SNII feedback is a strong regulator and suppressor of MBH growth, and that only an initial 10⁵ M_⊙ MBH is able to consistently accrete gas in the radiatively efficient regime (in the presence of SNII feedback). Combined with the fact that artificially induced gas inflows are unable to boost further gas accretion onto the MBH (even for an initial 10⁶ M_⊙ MBH), this suggests that it is primarily the nearby gravitational potential around the MBH that determines how much the MBH can grow via gas accretion over time (at least in an isolated non-cosmological environment).

We compute the primary Lund plane density for jets initiated by a massive ($b$) quark to single logarithmic accuracy in Quantum Chromodynamics (QCD). In order to capture mass effects, we consider quasi-collinear factorisation and we include contributions from the running of the QCD coupling and from collinear evolution, in a variable flavour-number scheme. Furthermore, the resummation of soft logarithms, including clustering effects, is performed numerically, keeping the full dependence on the $b$-quark mass. While our all-order results can be applied to both hadron and lepton colliders, we present, as first phenomenological application, the resummed calculation of the Lund plane density in $e^+e^-$ collisions at $\sqrt{s}=M_Z$, matched to tree-level matrix elements.

The measurement of dust size from millimeter-wavelength spectra provides direct constraints on grain growth in protoplanetary disks. Spectral indices between 0.88 and 2.9 mm have been measured in multiple young star-forming regions, such as Taurus, Ophiuchus, and Lupus, which have ages of 1-3 Myr. These spectral indices are as low as 2-3, suggesting that grains in disks are much larger than those in the interstellar medium. In this study, we analyze the ALMA archival data of 23 disks in the Upper Scorpius region. The observed wavelength is 2.9 mm in Band 3, the angular resolution is 3<inline-formula><tex-math id="TM0001" notation="LaTeX">${_{.}^{\prime\prime}}$</tex-math></inline-formula>3 <inline-formula><tex-math id="TM0002" notation="LaTeX">$\times$</tex-math></inline-formula> 2<inline-formula><tex-math id="TM0003" notation="LaTeX">${_{.}^{\prime\prime}}$</tex-math></inline-formula>1, which is not high enough to resolve the targets, and the rms noise is below <inline-formula><tex-math id="TM0004" notation="LaTeX">$0.075~\mathrm{mJy}~\mathrm{beam}^{-1}$</tex-math></inline-formula> for almost all sources. Together with the literature values of the Band 7 fluxes of the same targets, we find that the average spectral index of the disks in the Upper Scorpius region is <inline-formula><tex-math id="TM0005" notation="LaTeX">$\alpha _\mathrm{mm}=2.09\pm 0.10$</tex-math></inline-formula>, which is equal to or slightly smaller than those in the other younger regions. To explain the relationship between the fluxes and spectral indices of the disks in the Taurus, Ophiuchus, Lupus, and Upper Scorpius regions, we construct simple disk evolution models. The observations are best reproduced by models in which the inner radius of the disk increases. This suggests that a substantial amount of dust mass must persist in the outer disk regions where the dust temperature is lower than 20 K even at late evolutionary stages. These findings offer key insights into the grain growth and the temporal evolution of protoplanetary disks.

We investigate the conditions under which the perturbative treatment of the backreaction of spin-2 particles on the dynamics of an axion-SU(2) gauge field system breaks down during cosmic inflation. This condition is based on the ratio of the energy density of spin-2 particles from the SU(2) gauge field to that of the background field. The perturbative treatment breaks down when this ratio exceeds unity. We show that this occurs within a parameter space nearly identical to the strong backreaction regime identified in previous studies. However, in some cases, the ratio exceeds unity even before the system enters the strong backreaction regime. Our results suggest that attempts to study the strong backreaction regime using perturbation theory are necessarily limited. Reliable calculations require non-perturbative treatments, such as three-dimensional lattice simulations.

Origins of life research investigates how life could emerge from prebiotic chemistry only. One possible explanation provides the RNA world hypothesis. It states that life could emerge from RNA strands only, storing and transferring biological information, as well as catalyzing reactions as ribozymes. Before this state could have emerged, however, the prebiotic world was probably a purely chemical pool of short RNA strands with random sequences and without biological function performing hybridization and dehybridization, as well as ligation and cleavage. In this context relevant questions are what are the conditions that allow longer RNA strands to be built and how can information carrying in RNA sequence emerge? In order to investigate such RNA reactors, efficient simulations are needed because the space of possible RNA sequences increases exponentially with the length of the strands, as well as the number of reactions between two strands. In addition, simulations have to be compared to experimental data for validation and parameter calibration. Here, we present the MoRSAIK python package for sequence motif (or k-mer) reactor simulation, analysis and inference. It enables users to simulate RNA sequence motif dynamics in the mean field approximation as well as to infer the reaction parameters from data with Bayesian methods and to analyze results by computing observables and plotting. MoRSAIK simulates an RNA reactor by following the reactions and the concentrations of all strands inside up to a certain length (of four nucleotides by default). Longer strands are followed indirectly, by tracking the concentrations of their containing sequence motifs of that maximum length.

We present a very deep CO(3─2) observation of a massive, gas-rich, main sequence, barred spiral galaxy at z ≍ 1.52. Our data were taken with the IRAM-NOEMA interferometer for a 12-antenna equivalent on-source integration time of ∼50 hours. We fit the major axis kinematics with the forward modeling of a rotating disk and subtracted the two-dimensional beam convolved best-fit model, which revealed signatures of planar noncircular motions in the residuals. The inferred in-plane radial velocities are remarkably high, of the order of ≍60 km/s. Direct comparisons with a high-resolution, simulated, gas-rich, barred galaxy, obtained with the moving mesh code AREPO and the TNG sub-grid model, show that the observed noncircular gas flows can be explained as radial flows driven by the central bar, with an inferred net inflow rate of the order of the star formation rate (SFR). Given the recent evidence for a higher-than-expected fraction of barred disk galaxies at cosmic noon, our results suggest that rapid gas inflows due to bars could be important evolutionary drivers for the dominant population of star-forming galaxies at the peak epoch of star and galaxy formation.

It has been suggested some time ago that many black hole properties are not specific to gravity, but rather are shared by a large class of objects, the so-called saturons, that saturate the quantum field theoretic upper bound on microstate degeneracy. By now, various aspects of this universality have been understood and demonstrated in a number of explicit examples. In the present paper, we add one more brick to the building by showing that the decay of a simple two-dimensional saturated soliton copies some key aspects of the black hole decay as well as of the information retrieval. In particular, we study the evaporation process of a classically stable vacuum bubble of a spontaneously broken <inline-formula><mml:math><mml:mi>S</mml:mi><mml:mi>U</mml:mi><mml:mo>(</mml:mo><mml:mi>N</mml:mi><mml:mo>)</mml:mo></mml:math></inline-formula>-symmetry, coupled to massless fermions. We show that the decay rate as well as the characteristic energy of the emitted quanta are given by the inverse size of the object, in striking similarity with the Hawking evaporation of a black hole. The timescale of information retrieval also matches the one previously suggested for a black hole by Page. We give the semiclassical derivation of the phenomenon as well as its fully quantum resolution as a decaying coherent state of Goldstone bosons. The universal nature of the effect and its microscopic understanding support the analogous quantum portrait of a black hole as a saturated coherent state of gravitons.

Rocky planets orbiting M dwarf stars are prime targets for atmospheric characterization, yet their long-term evolution under intense stellar winds and high-energy radiation remains poorly constrained. The Kepler-1649 system, hosting two terrestrial exoplanets orbiting an M5V star, provides a valuable laboratory for studying atmospheric evolution in the extreme environments typical of M dwarf systems. In this Letter, we show that both planets could have retained atmospheres over gigayear timescales. Using a multispecies magnetohydrodynamic model, we simulate atmospheric ion escape driven by stellar winds and extreme-ultraviolet radiation from 0.8 to 4.0 Gyr. The results reveal a clear decline in total ion escape rates with stellar age, as captured by a nonparametric LOWESS regression, with O⁺ comprising 98.3%─99.9% of the total loss. Escape rates at 4.0 Gyr are 2 to 3 orders of magnitude lower than during early epochs. At 0.8 Gyr, planet b exhibits 3.79× higher O⁺ escape rates than planet c, whereas by 4.0 Gyr its O⁺ escape rates becomes 39.5× lower. This reversal arises from a transition to sub-magnetosonic star─planet interactions, where the fast magnetosonic Mach number, M_f, falls below unity. Despite substantial early atmospheric erosion, both planets may have retained significant atmospheres, suggesting potential long-term habitability. These findings offer predictive insight into atmospheric retention in the Kepler-1649 system and inform future JWST observations of similar M dwarf terrestrial exoplanets aimed at refining habitability assessments.

Possible deformed neutron halos in silicon isotopes are investigated from both structure and reaction perspectives using the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) combined with the Glauber model. The experimental neutron separation energies of silicon isotopes are well reproduced by the DRHBc theory. Multiple halo criteria are examined, including the global ones based on root-mean-square radii and density profiles, as well as the microscopic ones based on single-particle orbitals and their spatial distributions. Calculations employing different density functionals and pairing strengths consistently indicate the emergence of $p$-wave neutron halos in $^{43,45}$Si, accompanied by pronounced shape decoupling between the halo and the core. Moreover, the enhanced reaction cross sections and the narrow longitudinal momentum distributions of one-neutron removal residues provide additional evidence supporting the halo structures in $^{43,45}$Si.

Semi-classical dilaton gravity in (1+1)-dimensions remains one of the only arenas where quantum black holes can be exactly constructed, fully accounting for backreaction due to quantum matter. Here we provide a comprehensive analysis of the mass and thermodynamic properties of static asymptotically flat quantum black holes both analytically and numerically. First, we analytically investigate eternal quantum black hole solutions to a one-parameter family of analytically solvable models interpolating between Russo-Susskind-Thorlacius and Bose, Parker, and Peleg gravities. Examining these models in a semi-classically allowed parameter space, we find naked singularities may exist for quantum fields in the Boulware state. Using a quasi-local formalism, where we confine the black hole to a finite sized cavity, we derive the conserved energy and analyze the system's thermal behavior. Specifically, we show the semi-classical Wald entropy precisely equals the generalized entropy, accounting for both gravitational and fine grained matter entropies, and we find a range where the quantum black holes are thermally stable. Finally, we numerically construct eternal black hole solutions to semi-classical Callan-Giddings-Harvey-Strominger gravity and find their thermal behavior is qualitatively different from their analytic counterparts. In the process, we develop an analytic expansion of the solutions and find it accurately approximates the full numerical solutions in the semi-classical limit.

Active Galactic Nucleus (AGN) jets are thought to be vital ingredients in galaxy evolution through the action of kinetic feedback; however, how narrow, relativistic outflows couple to galaxies remains an open question. Jet deceleration, which is often attributed to the entrainment of material, such as stellar winds, is thought to be necessary for efficient coupling. We present a simple model of jet deceleration due to stellar mass-loading to investigate the energy budget of direct jet feedback in the local Universe. To this end, we produce models of stellar mass loss, including deriving a prescription for main-sequence mass-loss rates as a function of stellar population age. We pair this mass-loss data with a parametric fit for radio AGN incidence, predicting that a majority of jets are decelerated within their hosts, and generally replicate the expected FR-II fraction in LERGs. We calculate that ≳25% of the jet power in the local Universe is efficiently decelerated and available for direct feedback within galaxies for any stellar population age. This fraction is largely invariant to the shape of the radio AGN incidence function at low jet Eddington fractions. The stellar mass-loss rate evolves significantly over time, approximately following τ^−1.1, leading to corresponding decreases in decelerated jet power in older stellar populations. Although asymptotic giant branch stars dominate mass loss at all ages, we find that their stochasticity is important in low-mass galaxies, and derive a critical jet power below which main-sequence stars alone are sufficient to decelerate the jet.

We consider mixed strong-electroweak corrections to Higgs production via gluon fusion, in which the Higgs boson couples to the top quark. Using the method of differential equations, we compute all of the master integrals that contribute to this process at two loops through <inline-formula><mml:math><mml:mrow><mml:mi>O</mml:mi><mml:mo>(</mml:mo><mml:msup><mml:mrow><mml:mi>ϵ</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo>)</mml:mo></mml:mrow></mml:math></inline-formula> in the dimensional regularization parameter <inline-formula><mml:math><mml:mrow><mml:mi>ϵ</mml:mi><mml:mo>=</mml:mo><mml:mo>(</mml:mo><mml:mi>d</mml:mi><mml:mo>-</mml:mo><mml:mn>4</mml:mn><mml:mo>)</mml:mo><mml:mo>/</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:math></inline-formula>, keeping full analytic dependence on the top quark, Higgs, <inline-formula><mml:math><mml:mi>W</mml:mi></mml:math></inline-formula>, and <inline-formula><mml:math><mml:mi>Z</mml:mi></mml:math></inline-formula> boson masses. We present the results for these master integrals in terms of iterated integrals whose kernels depend on elliptic curves.

We calculate the θ dependence in a cousin of QCD, where the vacuum structure can be analyzed exactly. The theory is <inline-formula><mml:math><mml:mi>N</mml:mi></mml:math></inline-formula> = 2 SU(2) gauge theory with N_F = 0, 1, 2, 3 flavors of fundamentals, explicitly broken to <inline-formula><mml:math><mml:mi>N</mml:mi></mml:math></inline-formula> = 1 via an adjoint superpotential, and coupled to anomaly mediated supersymmetry breaking (AMSB). The hierarchy m_AMSB ≪ μ_𝒩=1 ≪ Λ ensures the validity of our IR analysis. As expected from ordinary QCD, the vacuum energy is a function of θ which undergoes 1st order phase transitions between different vacua where the various dyons condense. For N_F = 0 we find the expected phase transition at θ = π, while for N_F = 1, 2, 3 we find phase transitions at fractional values of π.

Axionlike particles (ALPs) are well-motivated examples of light, weakly coupled particles in theories beyond the Standard Model. In this work, we study long-lived ALPs coupled exclusively to leptons in the mass range between <inline-formula><mml:math><mml:mn>2</mml:mn><mml:msub><mml:mi>m</mml:mi><mml:mi>e</mml:mi></mml:msub></mml:math></inline-formula> and <inline-formula><mml:math><mml:msub><mml:mi>m</mml:mi><mml:mi>τ</mml:mi></mml:msub><mml:mo>-</mml:mo><mml:msub><mml:mi>m</mml:mi><mml:mi>e</mml:mi></mml:msub></mml:math></inline-formula>. For anarchic flavor structure the leptophilic ALP production in tau decays or from ALP-tau bremsstrahlung is enhanced thanks to derivative couplings of the ALP and can surpass production from electron and muon channels, especially for ALPs heavier than <inline-formula><mml:math><mml:msub><mml:mi>m</mml:mi><mml:mi>μ</mml:mi></mml:msub></mml:math></inline-formula>. Using past data from high-energy fixed-target experiments such as CHARM and BEBC we place new constraints on the ALP decay constant <inline-formula><mml:math><mml:msub><mml:mi>f</mml:mi><mml:mi>a</mml:mi></mml:msub></mml:math></inline-formula>, reaching scales as high as <inline-formula><mml:math><mml:mi>O</mml:mi><mml:mo>(</mml:mo><mml:msup><mml:mn>10</mml:mn><mml:mn>8</mml:mn></mml:msup><mml:mo>)</mml:mo><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>GeV</mml:mi></mml:math></inline-formula> in lepton-flavor-violating channels and <inline-formula><mml:math><mml:mrow><mml:msub><mml:mrow><mml:mi>f</mml:mi></mml:mrow><mml:mrow><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mo>∼</mml:mo><mml:mi>O</mml:mi><mml:mo>(</mml:mo><mml:msup><mml:mrow><mml:mn>10</mml:mn></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo>)</mml:mo><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>GeV</mml:mi></mml:mrow></mml:math></inline-formula> in lepton-flavor-conserving ones. We also present projections for the event-rate sensitivity of current and future detectors to ALPs produced at the Fermilab Main Injector, the CERN SPS, and in the forward direction of the LHC. We show that SHiP will be sensitive to <inline-formula><mml:math><mml:msub><mml:mi>f</mml:mi><mml:mi>a</mml:mi></mml:msub></mml:math></inline-formula> values that are over an order of magnitude above the existing constraints.

Luminous quasars at the redshift frontier z>7 serve as stringent probes of super-massive black hole formation and they are thought to undergo much of their growth obscured by dense gas and dust in their host galaxies. Fully characterizing the symbiotic evolution of SMBHs and hosts requires rest-frame optical observations that span spatial scales from the broad-line region to the ISM and CGM. JWST now provides the necessary spatially resolved spectroscopy to do so. But the physical conditions that regulate the interplay between SMBHs and their hosts at the highest redshifts, especially the nature of early feedback phases, remain unclear. We present JWST/NIRSpec IFU observations of J0313$-$1806 at z=7.64, the most distant luminous quasar known. From the restframe optical spectrum of the unresolved quasar, we derive a black hole mass of $M_\mathrm{BH}=(1.63 \pm 0.10)\times10^9 M_\odot$ based on H$β$ and an Eddington rate of $λ=L/L_\mathrm{Edd}=0.80\pm 0.05$, consistent with previous MgII-based estimates. J0313-1806 exhibits no detectable [O III] emission on nuclear scales. Most remarkably, we detect an ionized gas shell extending out to $\sim 1.8$ kpc traced by H$β$ emission that also lacks any significant [O III], with a $3σ$ upper limit on the [O III]$ λ$5007 to H$β$ flux ratio of $\log_{10} \left( F(\mathrm{[OIII]})/F(\mathrm{H}β)\right)=-1.15$. Through photoionization modelling, we demonstrate that the extended emission is consistent with a thin, clumpy outflowing shell where [OIII] is collisionally de-excited by dense gas. We interpret this structure as a fossil remnant of a recent blowout phase, providing evidence for episodic feedback cycles in one of the earliest quasars. These findings suggest that dense ISM phases may play a crucial role in shaping the spectral properties of quasars accross cosmic time.

Modern radio interferometers deliver large volumes of data containing high-sensitivity sky maps over wide fields-of-view. These large area observations can contain various and superposed structures such as point sources, extended objects, and large-scale diffuse emission. To fully realize the potential of these observations, it is crucial to build appropriate sky emission models which separate and reconstruct the underlying astrophysical components. We introduce aim-resolve, an automatic and iterative method that combines the Bayesian imaging algorithm resolve with deep learning and clustering algorithms in order to jointly solve the reconstruction and source extraction problem. The method identifies and models different astrophysical components in radio observations while providing uncertainty quantification of the results. By using different model descriptions for point sources, extended objects, and diffuse background emission, the method efficiently separates the individual components and improves the overall reconstruction. We demonstrate the effectiveness of this method on synthetic image data containing multiple different sources. We further show the application of aim-resolve to an L-band (856 - 1712 MHz) MeerKAT observation of the radio galaxy ESO 137-006 and other radio galaxies in that environment. We observe a reasonable object identification for both applications, yielding a clean separation of the individual components and precise reconstructions of point sources and extended objects along with detailed uncertainty quantification. In particular, the method enables the creation of catalogs containing source positions and brightnesses and the corresponding uncertainties. The full decoupling of sky emission model and instrument response makes the method applicable to a wide variety of instruments or wavelength bands.

On 2025 August 18, the LIGO─Virgo─KAGRA collaboration reported gravitational waves from a subthreshold binary neutron star merger. If astrophysical, this event would have a surprisingly low chirp mass, suggesting that at least one neutron star was below a solar mass. The Zwicky Transient Facility mapped the coarse localization and discovered a transient, ZTF 25abjmnps (AT2025ulz), which was spatially and temporally coincident with the gravitational-wave trigger. The first week of follow-up suggested properties reminiscent of a GW170817-like kilonova. Subsequent follow-up suggests properties most similar to a young, stripped-envelope, Type IIb supernova. Although we cannot statistically rule out chance coincidence, we undertake due diligence analysis to explore the possible association between ZTF 25abjmnps and S250818k. Theoretical models have been proposed wherein subsolar neutron star(s) may form (and subsequently merge) via accretion-disk fragmentation or core fission inside a core-collapse supernova—i.e., a "superkilonova." Here, we qualitatively discuss our multiwavelength dataset in the context of the superkilonova picture. Future higher-significance gravitational-wave detections of subsolar neutron star mergers with extensive electromagnetic follow-up would conclusively resolve this tantalizing multimessenger association.

The integration of aerodynamic drag is a fundamental step in simulating dust dynamics in hydrodynamical simulations. We propose a novel integration scheme, designed to be compatible with Strang splitting techniques, which allows for the straightforward integration of external forces and hydrodynamic fluxes in general-purpose hydrodynamic simulation codes. Moreover, this solver leverages an analytical solution to the problem of drag acceleration, ensuring linear complexity even in cases with multiple dust grain sizes, as opposed to the cubic scaling of methods that require a matrix inversion step. This new general implicit Runge─Kutta (GIRK) integrator is evaluated using standard benchmarks for dust dynamics such as DUSTYBOX, DUSTYWAVE, and DUSTYSHOCK. The results demonstrate not only the accuracy of the method but also the expected scalings in terms of accuracy, convergence to equilibrium, and execution time. GIRK can be easily implemented in hydrodynamical simulations alongside hydrodynamical steps and external forces and is especially useful in simulations with a large number of dust grain sizes.

Multiplanetary systems are excellent laboratories for studying the formation and evolution of exoplanets inside the same stellar environment. The number of known multiplanetary systems is expected to skyrocket with the advent of PLATO and the Roman space telescope. The spin-orbit angle is a key context information for the systems' dynamical history, and in recent years a growing number of planets had their spin-orbit angle measured, revealing a large diversity in orbital configurations, from well-aligned to polar, and even retrograde, orbits. Still, observers lack a robust tool to compare the dynamical state of different systems and to select the most suitable ones for future avenues of exploration, such as investigating the evolutionary pathways and their links to the atmospheric composition. Here, we present ExoNAMD, an open source code aimed at evaluating the dynamical state of multiplanetary systems via the Normalized Angular Momentum Deficit (NAMD) metric. The NAMD measures the deficit in angular momentum with respect to circular, co-planar orbits. It is normalized to compare systems with different architectures and provides a lower limit on the past dynamical excitation of the system. We find that using the spin-orbit angle parameter in the NAMD calculation (A-NAMD) improves the dynamical state's description, compared to using only the relative inclinations (R-NAMD). Comparison of A-NAMD and R-NAMD also yields powerful insights into the interplay between eccentricity and spin-orbit angle. ExoNAMD is a timely tool for easy and fast comparison of the myriad of exoplanetary systems to be discovered by PLATO and Roman, and to optimize the target selection and scientific output for future atmospheric characterization using ELTs, JWST, and Ariel.

Context. Disc winds driven by thermal and magnetic processes are thought to play a critical role in protoplanetary disc evolution. However, the relative contribution of each mechanism remains uncertain, particularly in light of their observational signatures. Aims. We investigate whether spatially resolved emission and synthetic spectral line profiles can be used to distinguish between thermally and magnetically driven winds in protoplanetary discs. Methods. We modelled three disc wind scenarios with different levels of magnetisation: a relatively strongly magnetised wind (β4), a rather weakly magnetised wind (β6), and a purely photoevaporative wind (PE). Using radiative transfer post-processing, we generated synthetic emission maps and line profiles for [OI] 6300 Å, [NeII] 12.81 μm, and o-H₂ 2.12 μm, and compared them with observational trends in the literature. Results. We find that the β4 model generally produces broader and more blueshifted low-velocity components across all tracers, consistent with compact emission regions and steep velocity gradients. The β6 and PE models yield narrower profiles with smaller blueshifts, in better agreement with most observed narrow low-velocity components (NLVCs). We also find that some line profile diagnostics, such as the inclination at maximum centroid velocity, are not robust discriminants. However, the overall blueshift and full width at half maximum of the low-velocity components provide reliable constraints. The β4 model reproduces the most extreme blueshifted NLVCs in observations, while most observed winds are more consistent with the β6 and PE models. Conclusions. Our findings reinforce previous conclusions that most observed NLVCs are compatible with weakly magnetised or purely photo-evaporative flows. The combination of line kinematics and emission morphology offers meaningful constraints on wind-driving physics, and synthetic line modelling remains a powerful tool for probing disc wind mechanisms.

We present the discovery of SN 2025wny (ZTF25abnjznp/GOTO25gqt) and spectroscopic classification of this event as the first gravitationally lensed Type I superluminous supernova (SLSN-I). Deep ground-based follow-up observations resolve four images of the supernova with <inline-formula> <mml:math><mml:mo>∼</mml:mo><mml:mn>1</mml:mn><mml:mover><mml:mrow><mml:mi>.</mml:mi></mml:mrow><mml:mrow><mml:mi>″</mml:mi></mml:mrow></mml:mover><mml:mn>7</mml:mn></mml:math> </inline-formula> angular separation from the main lens galaxy, each coincident with the lensed images of a background galaxy seen in archival imaging of the field. Spectroscopy of the brightest image shows narrow features matching absorption lines at a redshift of z = 2.010 and broad features matching those seen in superluminous SNe with far-UV coverage. We infer a magnification factor of μ ∼ 20─50 for the brightest image in the system, based on photometric and spectroscopic comparisons to other SLSNe-I. SN 2025wny demonstrates that gravitationally lensed SNe are in reach of ground-based facilities out to redshifts far higher than previously assumed, and provide a unique window into studying distant supernovae and the internal properties of dwarf galaxies, as well as for time-delay cosmography.

We aim to study the atmospheric properties of the warm Neptune GJ 436 b by combining a set of five transit events observed with the CARMENES spectrograph with one transit from CRIRES$^+$ so as to provide the most constrained results possible at high resolution. We removed telluric and stellar signals from the data using SysRem and potential planetary signals were investigated using the cross-correlation technique. Following standard procedures for undetected species, we performed injection recovery tests and Bayesian retrievals to place constraints on the detectability of the main near-infrared absorbers. In addition, we simulated ELT/ANDES observations by computing end-to-end in silico datasets with EXoPLORE. No molecular signals were detected in the atmosphere of GJ 436 b, which is consistent with previous studies. Combined CARMENES-CRIRES$^+$ injection-recovery and Bayesian retrieval analyses show that the atmosphere is likely covered by high-altitude clouds ($\sim$ $1$ mbar) at low and intermediate metallicities or, alternatively, is very metal-rich ($\gtrsim$ $900\times$ solar), which would suppress spectral features without invoking clouds. Simulations of ELT/ANDES observations suggest a boost by nearly an order of magnitude to the upper limit in the photon-limited regime, reaching $0.1$ mbar at $10$-$300\times$ solar metallicities. The joint analysis of all useful transit observations from CARMENES and CRIRES$^+$ provides the most stringent constraints to date on the atmospheric properties of GJ 436 b. Complementary CCF-based and retrieval approaches consistently indicate that the atmosphere is either cloudy or highly metal enriched. Any weak near-infrared absorption lines, if present, are likely to be below current detection limits. However, according to our simulations, these features may be revealed with ELT/ANDES even in single-transit observations.

The relation between the masses of supermassive black holes (SMBHs) and their host galaxies encodes information on their mode of growth, especially at the earliest epochs. The James Webb Space Telescope (JWST) has opened such investigations by detecting the host galaxies of active galactic nuclei (AGN) and more luminous quasars within the first billion years of the Universe (z ≳ 6). Here, we evaluate the relation between the mass of SMBHs and the total stellar mass of their host galaxies using a sample of nine quasars at 6.18 ≤ z ≤ 6.4 from the Subaru High-z Exploration of Low-luminosity Quasars survey with NIRCam and NIRSpec observations. We find that the observed location of these quasars in the SMBH─galaxy mass plane (<inline-formula> <mml:math><mml:mi>log</mml:mi><mml:msub><mml:mi>M</mml:mi><mml:mi>BH</mml:mi></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mi>M</mml:mi><mml:mo>⊙</mml:mo></mml:msub><mml:mo>∼</mml:mo><mml:mn>8</mml:mn></mml:math> </inline-formula>─9; <inline-formula> <mml:math><mml:mi>log</mml:mi><mml:msub><mml:mi>M</mml:mi><mml:mo>*</mml:mo></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mi>M</mml:mi><mml:mo>⊙</mml:mo></mml:msub><mml:mo>∼</mml:mo><mml:mn>9.5</mml:mn></mml:math> </inline-formula>─11) is consistent with a nonevolving intrinsic mass relation with dispersion (<inline-formula> <mml:math><mml:mn>0.8</mml:mn><mml:msubsup><mml:mrow><mml:mn>0</mml:mn></mml:mrow><mml:mrow><mml:mo>−</mml:mo><mml:mn>0.28</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo><mml:mn>0.23</mml:mn></mml:mrow></mml:msubsup></mml:math> </inline-formula> dex) higher than the local value (∼0.3─0.4 dex) of their more massive descendants. Our analysis is based on a forward model of systematics and includes a consideration of the impact of selection effects and measurement uncertainties with an assumption on the slope of the mass relation. While degeneracies between parameters persist, the best-fit solution has a reasonable AGN fraction (2.3%) of galaxies at z ∼ 6 with an actively growing UV-unobscured black hole. In particular, models with a substantially higher normalisation in M_BH would require an unrealistically low intrinsic dispersion (∼0.22 dex). Consequently, our results predict a large population of AGN at lower black hole masses, as are now just starting to be discovered in focused efforts with JWST.

TriPoDPy is a code simulating the dust evolution, including dust growth and dynamics in protoplanetary disks using the parametric dust model presented in (Pfeil et al., 2024). The simulation evolves a dust distribution in a one-dimensional grid in the radial direction. It's written in Python and the core routines are implemented in Fortran90. The code not only solves for the evolution of the dust but also the gas disk with the canonical alpha-description (Shakura & Sunyaev, 1973). In addition to the original model, we added descriptions of tracers for the dust and gas, which could be used for compositional tracking of additional components.

Luminosities of pre-main sequence stars evolve during the protoplanetary disc lifetime. This has a significant impact on the heating of their surrounding protoplanetary discs, the natal environments of planets. Moreover, stars of different masses evolve differently. However, this is rarely accounted for in planet formation models. We carry out pebble-driven core accretion planet formation modelling with focus on the impact of pre-main sequence stellar luminosity evolution on giant planet formation around host stars in the range of <inline-formula><tex-math>$1{-}2.4\ \rm M_{\odot }$</tex-math></inline-formula>. We find that giant planet formation is sensitive to the evolution of stellar luminosity, specifically the locations and times at which giant planet formation can occur depend on it. High stellar luminosity causes an increase in the scale height of the gas and pebbles, which may decrease the efficiency of pebble accretion, making it more challenging to form giant planets. This has important consequences for the composition of these giant planets, stressing the need to incorporate such aspects into planet formation models.

Changing-look active galactic nuclei (CL-AGNs) exhibit dramatic spectral variability on unexpectedly short timescales, challenging standard accretion flow models. Despite growing samples, the physical drivers of this extreme variability, and the potential link to host-galaxy properties, remain unknown. Regardless of the underlying mechanism, the transition between AGN-dominated and host-dominated spectra offers a unique opportunity to study relations between AGNs and their hosts within the same objects. We present intermediate-resolution spectroscopy of 23 CL-AGNs identified by the Sloan Digital Sky Survey V (SDSS-V), obtained with VLT/X-shooter and Gemini-N/GMOS. An analysis of the Mgii emission line observed in the spectra demonstrates that the majority of these sources cannot be driven by variable obscuration. Our CL-AGNs roughly follow the M_BH-sigma_* and M_BH-M_* relations of inactive galaxies, with a median black hole-to-stellar mass ratio of 0.38%, although they show hints of a shallower slope. We find no evidence that the stellar population properties of our CL-AGNs, including stellar mass, age, young stellar fraction, and star-formation rate differ from those of Type 2 AGNs in SDSS. These results suggest that CL-AGNs reside in typical AGN host galaxies and that their extreme variability is likely unrelated to host-galaxy environment, supporting the idea that CL-AGNs are not a distinct population, but rather represent a phase of normal AGN activity. This result, in turn, implies that CL-AGNs can serve as useful probes of the AGN-host connection, providing access to both AGN-dominated and host-dominated spectra of the same systems.

Generally, merger likelihood increases in denser environments; however, the large relative velocities at the centres of dense clusters are expected to reduce the likelihood of mergers for satellite galaxies. Tidal features probe the recent merger histories of galaxies. The Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) will produce an unprecedented sample of tidal features around millions of galaxies. We use LSST-like mock observations of galaxies at <inline-formula><tex-math>$z\sim 0$</tex-math></inline-formula> from the EAGLE, ILLUSTRISTNG, and MAGNETICUM PATHFINDER cosmological-hydrodynamical simulations to predict the occurrence rates of tidal features around satellite galaxies across group and cluster environments in the velocity─radius projected phase─space diagram to investigate the impact of these environments on tidal feature occurrence. We find that ancient infallers in the projected phase─space exhibit a decreasing tidal feature fraction with increasing halo mass, whereas recent infallers in the projected phase─space show unchanging tidal feature fractions with halo mass. Our results show, for the first time in cosmological simulations, a suppression of tidal feature fractions in the central regions of galaxy clusters, indicating a reduced merger rate due to higher cluster-centric velocities and lower galaxy total masses in the cluster centres. Using a toy model, we show that the presence of more tidal features in the recent infaller zone and cluster outskirts suggests that tidal features occur in interactions within infalling groups and dissipate by the time they are ancient infallers, indicating a <inline-formula><tex-math>$\lesssim 3\pm 2$</tex-math></inline-formula> Gyr survival time of tidal features within clusters.

The nebular phase of a supernova (SN) occurs several months to years after the explosion, when the ejecta become mostly optically thin yet there still is sufficient radioactive material to keep the supernova bright. The asymmetries created by the explosion are encoded into the line profiles of the emission lines which appear in the nebular phase. In order to make accurate predictions for these line profiles, Non-Local Thermodynamic Equilibrium (NLTE) radiative transfer calculations need to be carried out. In this work, we use \texttt{ExTraSS} (EXplosive TRAnsient Spectral Simulator) -- which was recently upgraded into a full 3D NLTE radiative transfer code (including photoionization and line-by-line transfer effects) -- to carry out such calculations. \texttt{ExTraSS} is applied to a 3D explosion model of a $9.0\,M_\odot$ H-rich progenitor which is evolved into the homologous phase. Synthetic spectra are computed and the lines from different elements are studied for varying viewing angles. The model spectra are also compared against observations of SN 1997D and SN 2016bkv. The model is capable of creating good line profile matches for both SNe, and reasonable luminosity matches for He, C, O, and Mg lines for SN 1997D -- however H$α$ and Fe I lines are too strong.

The gas-phase metallicity affects heating and cooling processes in the star-forming galactic interstellar medium (ISM) as well as ionizing luminosities, wind strengths, and lifetimes of massive stars. To investigate its impact, we conduct magnetohydrodynamic simulations of the ISM using the FLASH code as part of the SILCC project. The simulations assume a gas surface density of 10 M<inline-formula><tex-math>$_\odot$</tex-math></inline-formula> pc<inline-formula><tex-math>$^{-2}$</tex-math></inline-formula> and span metallicities from 1/50 to 1 Z<inline-formula><tex-math>$_\odot$</tex-math></inline-formula>. We include non-equilibrium thermochemistry, a space- and time-variable far-UV background and cosmic ray ionization rate, metal-dependent stellar tracks, the formation of H II regions, stellar winds, type II supernovae, and cosmic ray injection and transport. With the metallicity decreasing over the investigated range, the star formation rate decreases by more than a factor of 10, the mass fraction of cold gas decreases from 60 per cent to 2.3 per cent, while the volume filling fraction of the warm gas increases from 20 per cent to 80 per cent. Furthermore, the fraction of H<inline-formula><tex-math>$_\mathrm{2}$</tex-math></inline-formula> in the densest regions drops by a factor of 4, and the dense ISM fragments into approximately five times fewer structures at the lowest metallicity. Outflow mass loading factors remain largely unchanged, with values close to unity, except for a significant decline at the lowest metallicity. Including the major processes that regulate ISM properties, this study highlights the strong impact of gas phase metallicity on the star-forming ISM.

The current generation of cryogenic solid state detectors used in direct dark matter and <inline-formula><mml:math><mml:mrow><mml:mi>CE</mml:mi><mml:mi>ν</mml:mi><mml:mi>NS</mml:mi></mml:mrow></mml:math></inline-formula> searches typically reach energy thresholds of <inline-formula><mml:math><mml:mrow><mml:mi>O</mml:mi><mml:mo>(</mml:mo><mml:mn>10</mml:mn><mml:mo>)</mml:mo><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>eV</mml:mi></mml:mrow></mml:math></inline-formula> for nuclear recoils. For a reliable calibration in this energy regime a method has been proposed, providing monoenergetic nuclear recoils at low energies <inline-formula><mml:math><mml:mrow><mml:mo>∼</mml:mo><mml:mn>100</mml:mn><mml:mtext> </mml:mtext><mml:mi>eV</mml:mi><mml:mi>─</mml:mi><mml:mn>1</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>keV</mml:mi></mml:mrow></mml:math></inline-formula>. In this work we report on the observation of a peak at (<inline-formula><mml:math><mml:msubsup><mml:mn>1113.6</mml:mn><mml:mrow><mml:mo>-</mml:mo><mml:mn>6.5</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo><mml:mn>6.5</mml:mn></mml:mrow></mml:msubsup></mml:math></inline-formula>) <inline-formula><mml:math><mml:mi>eV</mml:mi></mml:math></inline-formula> in the data of an <inline-formula><mml:math><mml:msub><mml:mtext>Al</mml:mtext><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>O</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math></inline-formula> crystal in CRESST-III, which was irradiated with neutrons from an AmBe calibration source. We attribute this monoenergetic peak to the radiative capture of thermal neutrons on <inline-formula><mml:math><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Al</mml:mi></mml:mrow><mml:mrow><mml:mn>27</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math></inline-formula> and the subsequent deexcitation via single <inline-formula><mml:math><mml:mi>γ</mml:mi></mml:math></inline-formula> emission. We compare the measured results with the outcome of Geant4 simulations and investigate the possibility to make use of this effect for the energy calibration of <inline-formula><mml:math><mml:msub><mml:mtext>Al</mml:mtext><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>O</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math></inline-formula> detectors at low energies. We further investigate the possibility of a shift in the expected energy scale of this effect caused by the creation of defects in the target crystal.

In the case of nonspinning compact binary systems on quasi-elliptic orbits, I obtain the conservative map between the constants of motion (energy and angular momentum) and the fundamental (radial and azimuthal) frequencies at the fourth post-Newtonian order, including both instantaneous and tail contributions. This map is expressed in terms of an enhancement function of the eccentricity, which is appropriately resummed to ensure accuracy for any eccentricity; in particular, I recover known results for circular orbits. In order to obtain this map, the local dynamics are expressed using an action-angle formulation. The tail term is treated as a perturbation, which is first localized in time, then Delaunay-averaged. Both operations require a contact transformation of the phase-space variables, which I explicitly control. Using the first law of binary black hole mechanics, I then obtain the orbit-averaged redshift invariant for eccentric orbits at fourth post-Newtonian order; when properly accounting for the tail contributions, it perfectly agrees with analytical self-force at postgeodesic order [arXiv:2203.13832]. Finally, I use these results to re-express the fluxes of energy and angular momentum obtained at third post-Newtonian order in [arXiv:0711.0302] and [arXiv:0908.3854] in terms of fundamental frequencies.

Observations and high-resolution hydrodynamical simulations indicate that massive star clusters form through a complex hierarchical assembly. We use simulations including post-Newtonian dynamics (the BIFROST code) and stellar evolution (the SEVN module) to investigate this collisional assembly. With a full initial stellar mass function, we study the effect of initial binary, triple, and massive single stars (450 <inline-formula><tex-math>$\,\mathrm{M}_\odot$</tex-math></inline-formula>) on the assembly, structure, and kinematics of massive (<inline-formula><tex-math>$M_\mathrm{cl}\sim 10^6 M_\odot$</tex-math></inline-formula>, <inline-formula><tex-math>$N=1.8 \times 10^6$</tex-math></inline-formula>) star clusters. Simultaneously, intermediate mass black holes (IMBHs), potential seeds for supermassive black holes, can form and grow in our models by stellar collisions, tidal disruption events (TDEs) and black hole (BH) mergers. At a fixed cluster mass, stellar multiplicity or a high mass limit increase the numbers (up to <inline-formula><tex-math>$\sim$</tex-math></inline-formula>10) and masses (up to <inline-formula><tex-math>$10^4 \,\mathrm{M}_\odot$</tex-math></inline-formula>) of the formed IMBHs within the first 10 Myr of cluster evolution. The TDE rates peak at <inline-formula><tex-math>$\Gamma _\mathrm{tde}\sim 5 \times 10^{-5}$</tex-math></inline-formula> yr<inline-formula><tex-math>$^{-1}$</tex-math></inline-formula> after IMBH formation at <inline-formula><tex-math>$\sim 2$</tex-math></inline-formula> Myr. In all simulations, we find gravitational wave driven mergers involving stellar BHs and IMBHs. Initial multiplicity or a high mass limit also result in IMBH─IMBH mergers. The IMBH masses correlate with the initial cluster masses, surface densities, and velocity dispersions approximately as <inline-formula><tex-math>$M_\bullet \propto M_\mathrm{cl}$</tex-math></inline-formula>, <inline-formula><tex-math>$M_\bullet \propto \Sigma _\mathrm{h}^\mathrm{3/2}$</tex-math></inline-formula>, and <inline-formula><tex-math>$M_\bullet \propto \sigma ^\mathrm{3}$</tex-math></inline-formula>. Our results suggest the dense <inline-formula><tex-math>$z\sim 10$</tex-math></inline-formula> star clusters recently observed by the JWST host IMBHs with masses above <inline-formula><tex-math>$M_\bullet \gtrsim {10^4}\:\mathrm{M_\odot }$</tex-math></inline-formula>.

Among the available perturbative approaches in quantum field theory, heat kernel techniques provide a powerful and geometrically transparent framework for computing effective actions in nontrivial backgrounds. In this work, resummation patterns within the heat kernel expansion are examined as a means of systematically extracting nonperturbative information. Building upon previous results for Yukawa interactions and scalar quantum electrodynamics, we extend the analysis to spinor fields, demonstrating that a recently conjectured resummation structure continues to hold. The resulting formulation yields a compact expression that resums invariants constructed from the electromagnetic tensor and its spinorial couplings, while preserving agreement with known proper-time coefficients. Beyond its immediate computational utility, the framework offers a unified perspective on the emergence of nonperturbative effects (such as Schwinger pair creation) in relation to perturbative heat kernel data, and provides a basis for future extensions to curved spacetimes and non-Abelian gauge theories.

Classical Cepheids (CCs) have long been considered excellent tracers of the chemical evolution of the Milky Way's young disk. We present a homogeneous, NLTE spectroscopic analysis of 401 Galactic CCs, based on 1,351 high-resolution optical spectra, spanning Galactocentric distances from 4.6 to 29.3 kpc. Using PySME with MARCS atmospheres and state-of-the-art grids of NLTE departure coefficients, we derive atmospheric parameters and abundances for key species tracing multiple nucleosynthetic channels. Our sample-the largest CC NLTE dataset to date-achieves high internal precision and enables robust modeling of present-day thin-disk abundance patterns and radial gradients. We estimate abundance gradients using three analytic prescriptions (linear, logarithmic, bilinear with a break) within a Bayesian, outlier-robust framework, and we also apply Gaussian Process Regression to capture non-parametric variations. We find that NLTE atmospheric parameters differ systematically from LTE determinations. Moreover, iron and most elemental abundance profiles are better described by non-linear behavior rather than by single-slope linear models: logarithmic fits generally outperform simple linear models, while bilinear fits yield inconsistent break radii across elements. Gaussian Process models reveal a consistent outer-disk flattening of [X/H] for nearly all studied elements. The [X/Fe] ratios are largely flat with Galactocentric radius, indicating coherent chemical scaling with iron across the thin disk, with modest positive offsets for Na and Al and mild declines for Mn and Cu. Comparison with recent literature shows overall agreement but highlights NLTE-driven differences, especially in outer-disk abundances. These results provide tighter empirical constraints for chemo-dynamical models of the Milky Way and set the stage for future NLTE mapping with upcoming large spectroscopic surveys.

Dusty, submillimeter-selected galaxies without optical counterparts contribute a non-negligible fraction of the star formation in the early universe. However, such a population is difficult to detect through classical optical/UV-based surveys. We report the serendipitous discovery of such an optically dark galaxy, behind the quadruply lensed <inline-formula><tex-math>$z=2.56$</tex-math></inline-formula> quasar, H1413+117, offset to the north by 6<inline-formula><tex-math>$^{\prime \prime }$</tex-math></inline-formula>. From <inline-formula><tex-math>$^{12}$</tex-math></inline-formula>CO <inline-formula><tex-math>$J=4$</tex-math></inline-formula>─3, <inline-formula><tex-math>$J=6$</tex-math></inline-formula>─5, and part of the <inline-formula><tex-math>$J=13$</tex-math></inline-formula>─12 transitions, which all spatially coincide with a compact submillimeter continuum emission, we determine an unambiguous spectroscopic redshift, <inline-formula><tex-math>$z=3.386\pm 0.005$</tex-math></inline-formula>. This galaxy has a molecular mass <inline-formula><tex-math>$M_{\rm mol} \sim 10^{11}$</tex-math></inline-formula> M<inline-formula><tex-math>$_\odot$</tex-math></inline-formula> and a black hole mass <inline-formula><tex-math>$M_{\rm BH} \sim 10^{8}$</tex-math></inline-formula> M<inline-formula><tex-math>$_\odot$</tex-math></inline-formula>, estimated from <inline-formula><tex-math>$^{12}$</tex-math></inline-formula>CO <inline-formula><tex-math>$J=4$</tex-math></inline-formula>─3 and archival Chandra X-ray data (<inline-formula><tex-math>$L_{\rm 2-10,keV} \sim 4 \times 10^{44}$</tex-math></inline-formula> erg s<inline-formula><tex-math>$^{-1}$</tex-math></inline-formula>), respectively. We also estimate a total infrared luminosity of <inline-formula><tex-math>$L_{\rm FIR} = (2.8\pm {2.3}) \times 10^{12}$</tex-math></inline-formula> L<inline-formula><tex-math>$_\odot$</tex-math></inline-formula> and a stellar mass of <inline-formula><tex-math>$M_* \lesssim 10^{11}$</tex-math></inline-formula> M<inline-formula><tex-math>$_{\odot }$</tex-math></inline-formula>, from spectral energy distribution fitting. According to these simple mass estimations, this gas-rich and X-ray bright galaxy might be in a transition phase from starburst to quasar offering a unique case for studying galaxy-black hole co-evolution under extremely dusty conditions.

In standard (symmetry-breaking) first-order phase transitions, the frictional pressure on expanding bubble walls can be dominated by transition radiation -- the emission of a gauge boson with phase-dependent masses as particles present in the thermal plasma pass through bubble walls. This process is enhanced in the soft limit, and is known to produce a significant frictional effect that is proportional to the Lorentz factor $γ$ of the bubble wall, thereby prohibiting runaway behavior. We calculate the analogous pressure for phase transitions with symmetry restoration. In such transitions, we show that the pressure due to this process can be $\textit{negative}$, producing the opposite effect. However, when the Lorentz factor of the wall gets very large, the result approaches the same scaling as the standard scenarios. Therefore, phase transitions with symmetry restoration can feature an intermediate negative friction regime even in the presence of significant interactions with the plasma, and the bubble wall terminal Lorentz factor can be significantly larger (by more than an order of magnitude) than in the corresponding symmetry-breaking scenarios. This can carry important implications for various phenomenological applications, from gravitational waves to physics beyond-the-Standard-Model.

Context. Next-generation photometric and spectroscopic galaxy surveys will enable unprecedented tests of the concordance cosmological model and of galaxy formation and evolution. Fully exploiting their potential requires a precise understanding of the selection effects on galaxies and biases on measurements of their properties, which are required, above all, for accurate estimates of redshift distributions. The forward-modelling of galaxy surveys offers a powerful framework to simultaneously recover galaxy redshift distributions and characterise the observed galaxy population. Aims. We present GALSBI-SPS, a new stellar population synthesis (SPS)-based galaxy population model developed for cosmological and galaxy evolution studies. The model generates realistic galaxy catalogues, which we use to forward-model Hyper-Suprime Cam (HSC) observations in the COSMOS field. Methods. GALSBI-SPS samples the physical properties of galaxies from analytical parametrisations informed by GAMA, DEVILS, and literature data, it computes galaxy magnitudes with the generative SED package PROSPECT, and it simulates HSC images in the COSMOS field with UFig. We measured photometric properties consistently in real data and simulations. We compared redshift distributions and photometric and physical properties to observations and to those from the phenomenological GALSBI model. Results. GALSBI-SPS reproduces the observed g, r, i, z, y magnitude, colour, and size distributions down to i ≤ 23 with good accuracy. Median differences in magnitudes and colours remain below 0.14 mag, with the model covering the full colour space spanned by HSC data. Galaxy sizes are overestimated by ∼0.2″ on average and some tension exists in the g − r colour distribution, but the latter is comparable to that seen in the phenomenological GALSBI model. Redshift distributions show a mild positive offset (<inline-formula> 0.01 ≲ ∆̄z ≲ 0.08 <mml:math> <mml:mrow> <mml:mn>0.01</mml:mn> <mml:mo>≲</mml:mo> <mml:mi>∆</mml:mi> <mml:mover> <mml:mrow> <mml:mi>z</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>̄</mml:mo> </mml:mrow> </mml:mover> <mml:mo>≲</mml:mo> <mml:mn>0.08</mml:mn> </mml:mrow> </mml:math> </inline-formula>) in the mean. GALSBI-SPS qualitatively reproduces the stellar mass─star formation rate and size─stellar mass relations seen in COSMOS2020 data. Conclusions. GALSBI-SPS provides a realistic, survey-independent description of the galaxy population at a Stage-III-like depth using only literature-based parameters. Its predictive power is expected to improve significantly when constrained against deep observed data using simulation-based inference, thereby providing accurate redshift distributions that satisfy the stringent requirements set by Stage IV surveys.

Neutron supermirrors are a crucial part of many scattering and particle physics experiments. So far, Ni(Mo)/Ti supermirrors have been used in experiments that require to transport a polarized neutron beam due to their lower saturation magnetization compared to Ni/Ti supermirrors. However, next generation <mml:math><mml:mi>β</mml:mi></mml:math> decay experiments require supermirrors that depolarize below <mml:math><mml:mrow><mml:mn>1</mml:mn><mml:msup><mml:mrow><mml:mn>0</mml:mn></mml:mrow><mml:mrow><mml:mo>‑</mml:mo><mml:mn>4</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math> per reflection to reach their targeted precision. The depolarization of a polarized neutron beam due to reflection off Ni(Mo)/Ti supermirrors has not yet been measured to that precision. Recently, Cu/Ti supermirrors with a lower saturation magnetization compared to Ni(Mo)/Ti have been developed, and may serve as an alternative. In this paper, we test the performance of both mirrors. At a first stage, we present four-states polarized neutron reflectivity curves of Ni(Mo) and Cu monolayers and <mml:math><mml:mrow><mml:mi>m</mml:mi><mml:mo>=</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:math> Ni(Mo)/Ti and Cu/Ti supermirrors measured at the neutron reflectometer SuperADAM and perform a full polarization analysis, with the aim to extract information about their magnetic moment. The results found, however, were inconclusive, since it seems a detection limit of this method for all measured samples was reached. At a second stage, we measured the depolarization (<mml:math><mml:mi>D</mml:mi></mml:math>) that a polarized neutron beam suffers after reflection off the same Ni(Mo)/Ti and Cu/Ti supermirrors by using the Opaque Test Bench setup. We find upper limits for the depolarization of <mml:math><mml:mrow><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mtext>Cu/Ti(4N5)</mml:mtext></mml:mrow></mml:msub><mml:mo><</mml:mo><mml:mn>7</mml:mn><mml:mo>.</mml:mo><mml:mn>6</mml:mn><mml:mo>×</mml:mo><mml:mn>1</mml:mn><mml:msup><mml:mrow><mml:mn>0</mml:mn></mml:mrow><mml:mrow><mml:mo>‑</mml:mo><mml:mn>5</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>, <mml:math><mml:mrow><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mtext>Ni(Mo)/Ti</mml:mtext></mml:mrow></mml:msub><mml:mo><</mml:mo><mml:mn>8</mml:mn><mml:mo>.</mml:mo><mml:mn>5</mml:mn><mml:mo>×</mml:mo><mml:mn>1</mml:mn><mml:msup><mml:mrow><mml:mn>0</mml:mn></mml:mrow><mml:mrow><mml:mo>‑</mml:mo><mml:mn>5</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>, and <mml:math><mml:mrow><mml:msub><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mtext>Cu/Ti(2N6)</mml:mtext></mml:mrow></mml:msub><mml:mo><</mml:mo><mml:mn>6</mml:mn><mml:mo>.</mml:mo><mml:mn>0</mml:mn><mml:mo>×</mml:mo><mml:mn>1</mml:mn><mml:msup><mml:mrow><mml:mn>0</mml:mn></mml:mrow><mml:mrow><mml:mo>‑</mml:mo><mml:mn>5</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math> at the <mml:math><mml:mrow><mml:mn>1</mml:mn><mml:mi>σ</mml:mi></mml:mrow></mml:math> confidence level, where (4N5) corresponds to a Ti purity of <mml:math><mml:mrow><mml:mn>99</mml:mn><mml:mo>.</mml:mo><mml:mn>995</mml:mn><mml:mspace></mml:mspace><mml:mstyle><mml:mi>%</mml:mi></mml:mstyle></mml:mrow></mml:math> and (2N6) to <mml:math><mml:mrow><mml:mn>99</mml:mn><mml:mo>.</mml:mo><mml:mn>6</mml:mn><mml:mspace></mml:mspace><mml:mstyle><mml:mi>%</mml:mi></mml:mstyle></mml:mrow></mml:math>. These results show that all three supermirrors are suitable for being used in next generation <mml:math><mml:mi>β</mml:mi></mml:math> decay experiments. We found no noticeable dependence of the depolarization on the <mml:math><mml:mi>q</mml:mi></mml:math> value or the magnetizing field, in which the samples were placed.

We present Aletheia, a new emulator of the non-linear matter power spectrum, $P(k)$, built upon the evolution mapping framework. This framework addresses the limitations of traditional emulation by focusing on $h$-independent cosmological parameters, which can be separated into those defining the linear power spectrum shape ($\mathbfΘ_{\mathrm{s}}$) and those affecting only its amplitude evolution ($\mathbfΘ_{\mathrm{e}}$). The combined impact of evolution parameters and redshift is compressed into a single amplitude parameter, $σ_{12}$. Aletheia uses a two-stage Gaussian Process emulation: a primary emulator predicts the non-linear boost factor as a function of ($\mathbfΘ_{\mathrm{s}}$) and $σ_{12}$ for fixed evolution parameters, while a second one applies a small linear correction based on the integrated growth history. The emulator is trained on shape parameters spanning $\pm$5$σ$ of Planck constraints and a wide clustering range $0.2 < σ_{12} < 1.0$, providing predictions for $0.006\,{\rm Mpc}^{-1} < k < 2\,{\rm Mpc}^{-1}$. We validate Aletheia against N-body simulations, demonstrating sub-percent accuracy. When tested on a suite of dynamic dark energy models, the full emulator's predictions show a variance of approximately 0.2%, a factor of five smaller than that of the state-of-the-art EuclidEmulator2 (around 1% variance). Furthermore, Aletheia maintains sub-percent accuracy for the best-fit dynamic dark energy cosmology from recent DESI data, a model whose parameters lie outside the training ranges of most conventional emulators. This demonstrates the power of the evolution mapping approach, providing a robust and extensible tool for precision cosmology.

Disc winds driven by thermal and magnetic processes are thought to play a critical role in protoplanetary disc evolution. However, the relative contribution of each mechanism remains uncertain, particularly in light of their observational signatures. We investigate whether spatially resolved emission and synthetic spectral line profiles can distinguish between thermally and magnetically driven winds in protoplanetary discs. We modelled three disc wind scenarios with different levels of magnetisation: a relatively strongly magnetised wind (β4), a rather weakly magnetised wind (β6), and a purely photoevaporative wind (PE). Using radiative transfer post-processing, we generated synthetic emission maps and line profiles for [OI] 6300 Å, [NeII] 12.81 μm, and o-H2 2.12 μm, and compared them with observations. The β4 model generally produces broader and more blueshifted low-velocity components across all tracers, consistent with compact emission regions and steep velocity gradients. The β6 and PE models yield narrower profiles with smaller blueshifts, in better agreement with most observed narrow low-velocity components (NLVCs). We also find that some line profile diagnostics, such as the inclination at maximum centroid velocity, are not robust discriminants. However, the overall blueshift and full-width at half-maximum (FWHM) of the low-velocity components provide reliable constraints. The β4 model reproduces the most extreme blueshifted NLVCs in observations, while most observed winds are more consistent with the β6 and PE models. Our findings reinforce previous conclusions that most observed NLVCs are compatible with weakly magnetised or purely photoevaporative flows. The combination of line kinematics and emission morphology offers meaningful constraints on wind-driving physics.

GRB 250702B is an exceptional transient that produced multiple episodes of luminous gamma-ray radiation lasting for >25 ks, placing it among the class of ultralong gamma-ray bursts (GRBs). However, unlike any known GRB, the Einstein Probe detected soft-X-ray emission up to 24 hr before the gamma-ray triggers. We present comprehensive X-ray observations of the transient's "afterglow" obtained with the Neil Gehrels Swift Observatory, the Nuclear Spectroscopic Telescope Array, and the Chandra X-ray Observatory between 0.5 and 65 days (observer frame) after the initial high-energy trigger. The X-ray emission decays steeply as ∼t^−1.9 and shows short-timescale X-ray variability (∆T/T < 0.03) in both Swift and NuSTAR, consistent with flares superposed on an external shock continuum. Serendipitous detections by the Swift Burst Alert Telescope out to ∼0.3 days and continued NuSTAR variability to ∼2 days imply sustained central engine activity; including the early Einstein Probe X-ray detections, the required engine duration is ≳3 days. Afterglow modeling favors the combination of forward- and reverse-shock emission in a windlike (k ≍ 2) environment. These properties, especially the long-lived engine and early soft-X-ray emission, are difficult to reconcile with a collapsar origin, and GRB 250702B does not fit neatly with canonical ultralong GRBs or relativistic tidal disruption events (TDEs). A "hybrid" scenario, in which a star is disrupted by a stellar-mass black hole (a micro-TDE), provides a plausible explanation, although a relativistic TDE from an intermediate-mass black hole remains viable.

Classical Cepheids are among the most important distance calibrators and play a crucial role in the calibration as the first rung of the extragalactic distance ladder. Given their typical age, they also constitute an optimal tracer of the young population in the Galactic disc. We aim to increase the number of available DCEPS with high-resolution spectroscopic metallicities, to study the galactocentric radial gradients of several chemical elements and analyse the spatial distribution of the Galactic young population of stars in the Milky Way disc. We performed a complete spectroscopical analysis of 136 spectra obtained from three different high-resolution spectrographs, for a total of 60 DCEPs. More than half have pulsational periods longer than 15 days, up to 70 days, doubling the number of stars in our sample with P>15d. We derived radial velocities, atmospheric parameters and chemical abundances up to 33 different species. We present an updated list of trusted spectroscopic lines for the detection and estimation of chemical abundances. We used this new set to revisit the abundances already published in the context of the C-MetaLL survey and increase the number of available chemical species. For the first time (to our knowledge), we present the estimation of abundances for Dysprosium, as well as a systematic estimation of Erbium, Lutetium and Thorium abundances. We calculate a galactic radial gradient for [Fe/H] with a slope of $-0.064\pm0.002$, in good agreement with recent literature estimation. The other elements also exhibit a clear negative radial trend, with this effect diminishing and eventually disappearing for heavier neutron-capture elements. Depending on the proposed spiral arms model present in several literature sources, our most external stars agree on tracing either the Perseus, the Norma-Outer or both the Outer and the association Outer-Scutum-Centaurus (OSC) arms.

Context. While most chemical abundance studies of Cepheids rely on optical spectroscopy, near-infrared (NIR) observations offer advantages in terms of reduced extinction and access to new elemental tracers. Aims. We aim to validate NIR-based abundance determinations against optical results and to explore the diagnostic power of spectral lines inaccessible in the optical domain. The H and K bands allow us to trace elements such as P, K, and Yb, while also probing obscured Galactic regions and more distant Cepheids. Methods. We obtained high-resolution (R=45000) H- and K-band spectra for 21 Galactic and 2 LMC Classical Cepheids using IGRINS. Atmospheric parameters were derived from photometry and line-depth ratios (Teff), empirical calibrations (log g), and spectral fitting. Abundances of 16 elements were determined via LTE full spectral synthesis and compared with optical literature values. Results. We find excellent agreement between NIR and optical abundances, confirming the reliability of IGRINS-based measurements. The Fe, Mg, and Si gradients match previous optical determinations. We provide the first homogeneous NIR-based measurements of P, K, and Yb in Cepheids, consistent with chemical evolution models. The two LMC Cepheids in our sample, also studied optically, serve as extragalactic benchmarks for validating NIR abundances in low-metallicity regimes. Conclusions. High-resolution NIR spectroscopy yields accurate chemical abundances in Cepheids, consistent with optical results, and grants access to additional nucleosynthetic tracers. These results support future large NIR spectroscopic surveys with instruments such as MOONS, ELT, and JWST for Galactic and extragalactic archaeology.

We present primordial non-Gaussianity predictions from a new high-precision code for simulating axion-U(1) inflation on a discrete lattice. We measure the primordial scalar curvature power spectrum and bispectrum from our simulations, determining their dependence on both scale and axion-gauge coupling strength. Both the gauge-sourced power spectrum and the bispectrum exhibit a strong blue tilt due to our choice of an <inline-formula><mml:math><mml:mi>α</mml:mi></mml:math></inline-formula>-attractor inflaton potential. We provide fitting functions for the power spectrum and bispectrum that accurately reproduce these statistics across a wide range of scales and coupling strengths. While our fitting function for the bispectrum has a separable form, results from high-resolution simulations demonstrate that the full shape is not separable. Thus, our simulations generate realizations of primordial curvature perturbations with nontrivial correlators that cannot be generated using standard techniques for primordial non-Gaussianity. We derive bounds on the axion-gauge coupling strength based on the bispectrum constraints from the cosmic microwave background, demonstrating a new method for constraining inflationary primordial non-Gaussianity by simulating the nonlinear dynamics.

Quasi-periodic eruptions (QPEs) are recurring X-ray bursts originating from the vicinity of supermassive black holes, but their driving mechanisms remain under debate. This study analyzes new NICER observations of QPEs in Ansky (a transient event in the nucleus of the galaxy SDSS J1335+0728), taken between January and June 2025. By examining flare durations, peak-to-peak recurrence times, and profiles, we compare the 2025 data with those from 2024 to investigate changes in energy, timescales, and flare shapes. The 2025 QPEs are found to be four times more energetic, with recurrence times of approximately 10 days and flare durations ranging from 2.5 to 4 days, making them both about twice as long as in 2024. Additionally, the flare profiles have become more asymmetric, showing longer decays. We explore different theoretical scenarios to explain the observed properties of the QPEs in Ansky, including evolving stream─disk interactions in an extreme mass-ratio inspiral system as a potential mechanism behind the observed changes in recurrence time and energetics, while also considering alternative models based on mass transfer and accretion disk instabilities. Continued observational efforts will be crucial for unveiling the nature of Ansky.

Current cosmological simulations rely on active galactic nucleus (AGN) feedback to quench star formation and match observed stellar mass distributions, but models for AGN feedback are poorly constrained. The circumgalactic medium (CGM) provides a valuable laboratory to study this process, as its metallicity, temperature, and density distributions are directly shaped by AGN activity. Recent observations from the eROSITA instrument provide constraints on the CGM through measurements of extended soft X-ray emission. In this work, we generate synthetic eROSITA observations from the EAGLE and SIMBA cosmological simulations and compare them to observations of galaxies stacked by stellar mass, halo mass, and star formation rate. SIMBA outperforms EAGLE in matching observed surface brightness profiles, but neither simulation achieves consistent agreement with observations across the full range of galaxy properties we studied. We find that variations in CGM X-ray emission between simulations are primarily driven by density differences at R ≲ 0.2R_200c and temperature and metallicity changes at larger radii. These results highlight the need for further refinement of AGN feedback models in cosmological simulations and demonstrate the power of stacked X-ray observations as a tool for constraining feedback physics.

We calculate energy correlators in a holographic model incorporating elements of asymptotic freedom and confinement. We model a running coupling by considering a geometry with a warp factor that deviates logarithmically from anti-de Sitter (AdS). A novel aspect of our bulk metric is that it smoothly interpolates between a Randall-Sundrum solution with a hard wall and a geometry corresponding to a logarithmic running typical of gauge theories. By studying shockwave deformations of this metric, we compute a two-point energy correlator assuming a high-energy scalar source. This extends techniques recently developed for correlators in asymptotically AdS geometries. We use numerical methods to find the profile of shockwaves along the extra dimension, as it does not admit an analytical form. The running coupling leads to a decay of the two-point correlator at small angular separation, unlike the flat correlator one finds in AdS. In the back-to-back limit we observe an exponential falloff similar to other hard-wall models.

Forward modeling the galaxy density within the Effective Field Theory of Large Scale Structure (EFT of LSS) enables field-level analyses that are robust to theoretical uncertainties. At the same time, they can maximize the constraining power from galaxy clustering on the scales amenable to perturbation theory. In order to apply the method to galaxy surveys, the forward model must account for the full observational complexity of the data. In this context, a major challenge is the inclusion of redshift space distortions (RSDs) from the peculiar motion of galaxies. Here, we present improvements in the efficiency and accuracy of the RSD modeling in the perturbative LEFTfield forward model. We perform a detailed quantification of the perturbative and numerical error for the prediction of momentum, velocity and the redshift-space matter density. Further, we test the recovery of cosmological parameters at the field level, namely the growth rate f, from simulated halos in redshift space. For a rigorous test and to scan through a wide range of analysis choices, we fix the linear (initial) density field to the known ground truth but marginalize over all unknown bias coefficients and noise amplitudes. With a third-order model for gravity and bias, our results yield < 1 % statistical and < 1.5 % systematic error. The computational cost of the redshift-space forward model is only ∼ 1.5 times of the rest frame equivalent, enabling future field-level inference that simultaneously targets cosmological parameters and the initial matter distribution.

This paper offers a historical overview of the origins and enduring significance of gravitational particle creation, a groundbreaking discovery first formulated in Leonard Parker's 1966 doctoral thesis at Harvard University. By tracing the context in which Parker developed this idea and examining its subsequent influence, the paper highlights how the concept of gravitational particle creation advanced the study of quantum field theory in curved spacetime and profoundly shaped modern cosmology, as well as the quantum theory of black holes.

The combined use of the inverse kinematics technique and the advanced detection setup R³B (Reactions with Relativistic Radioactive Beams) at GSI/FAIR provides unique opportunities to study the fission process. This approach provides access to the complete isotopic identification of the two fission fragments, the precise determination of their velocities and the measurement of the neutrons and gammas emitted in coincidence, for a wide range of unstable fissile nuclei. In addition, quasi-free NN scattering represents a surrogate reaction to induce fission, allowing the complete identification of the fissioning system in terms of isotopic composition and excitation energy. The manuscript describes the technical realisation of these experiments as well as the physics programme and some preliminary results.

We present a systematic method for deriving partial-wave unitarity bounds on Wilson coefficients of higher-dimensional operators in effective field theories involving more than four fields, which naturally appear in tree-level 2-to-$N$ scattering processes with $N \geq 3$. Unlike 2-to-2 scattering, 2-to-$N$ scattering with $N \geq 3$ features multiple amplitudes associated with the same total angular momentum. To resolve these degeneracies, we provide a way to construct an orthonormal amplitude basis by parameterizing the phase space manifold of massless particles using spinor-helicity variables, enabling analytical integration over the phase space with arbitrary particle numbers. We provide Mathematica code to analytically evaluate phase space integrals of interference between two local on-shell amplitudes up to four final-state particles, with straightforward generalization to $N$ final-state particles. As practical applications, we demonstrate the use of this tool by deriving unitarity bounds on some dimension-7 and dimension-8 operators in the Standard Model effective field theory involving five and six fields, respectively.

Biological and artificial systems encode information through complex nonlinear operations across multiple timescales. A clear understanding of the interplay between this multiscale structure and the nature of nonlinearities at play is, however, missing. Here, we study a general model where the input signal is propagated to an output unit through a processing layer via nonlinear activation functions. We focus on two widely implemented paradigms: nonlinear summation, where signals are first nonlinearly transformed and then combined; nonlinear integration, where they are combined first and then transformed. We find that fast-processing capabilities systematically enhance input-output mutual information, and nonlinear integration outperforms summation in large systems. Conversely, a nontrivial interplay between the two strategies emerges in lower dimensions as a function of interaction strength, heterogeneity, and sparsity of conections between the units. Finally, we reveal a tradeoff between input and processing sizes in strong-coupling regimes. Our results shed light on relevant features of nonlinear information processing with implications for both biological and artificial systems.

Since the first observations of interstellar molecules, astrochemical simulations have been employed to model and understand its formation and destruction path- ways. With the advent of high-resolution telescopes such as JWST and ALMA, the number of detected molecules has increased significantly, thereby creating a need for increasingly complex chemical reaction networks. To model such complex systems, we have developed Carbox, a new astrochemical simulation code that leverages the modern high-performance transformation framework Jax. With Jax enabling computational efficiency and differentiability, Carbox can easily utilize GPU acceleration, be used to study sensitivity and uncertainty, and interface with advances in Scientific Machine Learning. All of these features are crucial for modeling the molecules observed by current and next-generation telescopes.

Cosmic-ray physics in the GeV-to-TeV energy range has entered a precision era thanks to recent data from space-based experiments. However, the poor knowledge of nuclear reactions, in particular for the production of antimatter and secondary nuclei, limits the information that can be extracted from these data, such as source properties, transport in the Galaxy and indirect searches for particle dark matter. The Cross-Section for Cosmic Rays at CERN workshop series has addressed the challenges encountered in the interpretation of high-precision cosmic-ray data, with the goal of strengthening emergent synergies and taking advantage of the complementarity and know-how in different communities, from theoretical and experimental astroparticle physics to high-energy and nuclear physics. In this paper, we present the outcomes of the third edition of the workshop that took place in 2024. We present the current state of cosmic-ray experiments and their perspectives, and provide a detailed road map to close the most urgent gaps in cross-section data, in order to efficiently progress on many open physics cases, which are motivated in the paper. Finally, with the aim of being as exhaustive as possible, this report touches several other fields – such as cosmogenic studies, space radiation protection and hadrontherapy – where overlapping and specific new cross-section measurements, as well as nuclear code improvement and benchmarking efforts, are also needed. We also briefly highlight further synergies between astroparticle and high-energy physics on the question of cross-sections.

Chemotaxis allows single cells to self-organize at the population level, as classically described by Keller-Segel models. We show that chemotactic aggregation can be understood using a generalized Maxwell construction based on the balance of density fluxes and reactive turnover. This formulation implies that aggregates generically undergo coarsening, which is interrupted and reversed by cell growth and death. Together, both stable and spatiotemporally dynamic aggregates emerge. Our theory mechanistically links chemotactic self-organization to phase separation and reaction-diffusion patterns.

We further scrutinize the evidence for a recently suggested pseudoscalar particle, the electroweak <inline-formula><mml:math><mml:msub><mml:mi>η</mml:mi><mml:mi>w</mml:mi></mml:msub></mml:math></inline-formula> meson. Its existence is demanded by matching the removal of the weak vacuum angle <inline-formula><mml:math><mml:msub><mml:mi>θ</mml:mi><mml:mi>w</mml:mi></mml:msub></mml:math></inline-formula> by the anomalous <inline-formula><mml:math><mml:mi>B</mml:mi><mml:mo>+</mml:mo><mml:mi>L</mml:mi></mml:math></inline-formula> symmetry with a massive pole in the topological susceptibility of the vacuum. We specifically focus on the possibility of the emergence of <inline-formula><mml:math><mml:msub><mml:mi>η</mml:mi><mml:mi>w</mml:mi></mml:msub></mml:math></inline-formula> as a collective excitation of the phase of the condensate of the 't Hooft fermion determinant, generated by the electroweak instantons, which breaks the <inline-formula><mml:math><mml:mi>B</mml:mi><mml:mo>+</mml:mo><mml:mi>L</mml:mi></mml:math></inline-formula> symmetry spontaneously. We argue that the generation of the 't Hooft vertex is in one-to-one correspondence with its nonzero vacuum expectation value which is cutoff insensitive. We outline certain puzzles about the nature of the emergent <inline-formula><mml:math><mml:msub><mml:mi>η</mml:mi><mml:mi>w</mml:mi></mml:msub></mml:math></inline-formula> which require further investigation.

We address the question whether the magnetorotational instability (MRI) can operate in the near-surface shear layer (NSSL) of the Sun and how it affects the interaction with the dynamo process. Using hydromagnetic mean-field simulations of αΩ-type dynamos in rotating shearing-periodic boxes, we show that for negative shear the MRI can operate above a certain critical shear parameter. This parameter scales inversely with the equipartition magnetic field strength above which α quenching set in. Like the usual Ω effect, the MRI produces toroidal magnetic field when the field is sufficiently strong. The work done by the Lorentz force is positive, so the magnetic field drives kinetic energy and not the other way around, as in a turbulent dynamo. This results in strong kinetic energy production and dissipation, which occurs at the expense of the magnetic energy. In view of the application to the solar NSSL, we conclude that the turbulent magnetic diffusivity may be too large for the MRI to be excited and that therefore only the standard Ω effect is expected to operate.

Autochemotaxis, the directed movement of cells along gradients in chemicals they secrete, is central to the formation of complex spatiotemporal patterns in biological systems. Since the introduction of the Keller-Segel model, numerous variants have been analyzed, revealing phenomena such as coarsening of aggregates, stable aggregate sizes, and spatiotemporally chaotic dynamics. Here we consider general mass-conserving Keller-Segel models, that is, models without cell growth and death, and analyze the generic long-time dynamics of the chemotactic aggregates. Building on and extending our previous work, which demonstrated that chemotactic aggregation can be understood through a generalized Maxwell construction balancing density fluxes and reactive turnover, we use singular perturbation theory to derive the rates of mass competition between well-separated aggregates. We analyze how this mass-competition process drives coarsening in both diffusion- and reaction-limited regimes, with the diffusion-limited rate aligning with our previous quasi-steady-state analyses. Our results generalize earlier mathematical findings, demonstrating that coarsening is driven by self-amplifying mass transport and aggregate coalescence. Additionally, we provide a linear stability analysis of the lateral instability, predicting it through a nullcline-slope criterion that parallels the curvature criterion in spinodal decomposition. Overall, our findings suggest that chemotactic aggregates behave similarly to phase-separating droplets, providing a robust framework for understanding the coarse-grained dynamics of autochemotactic cell populations and a quantitative basis for comparing chemotactic coarsening to canonical nonequilibrium phase separation.

We study the implications of noninvertible chiral symmetry in a four-dimensional U(1) gauge theory coupled to massless fermions with electromagnetic <inline-formula><mml:math><mml:mi>S</mml:mi><mml:mi>L</mml:mi><mml:mo>(</mml:mo><mml:mn>2</mml:mn><mml:mo>,</mml:mo><mml:mi>Z</mml:mi><mml:mo>)</mml:mo></mml:math></inline-formula> duality. This is done by deriving the Adler-Bell-Jackiw anomaly of massless QED in the dual frame that is used to explicitly construct the symmetry defect operator as well as the conserved two-form symmetry current. As expected, the noninvertible chiral symmetry is covariant under the duality transformation. This has implications for understanding the nature of kinetic and topological terms in the dual frame and for axion electrodynamics. In particular, we show that to generate an axion potential from a dyon loop, the one-form magnetic symmetry must be explicitly broken by a mutually nonlocal charged state with nonzero pairwise helicity.

Cosmic microwave background (CMB) photons are deflected by large-scale structure through gravitational lensing. This secondary effect introduces higher-order correlations in CMB anisotropies, which are used to reconstruct lensing deflections. This allows mapping of the integrated matter distribution along the line of sight, probing the growth of structure, and recovering an undistorted view of the last-scattering surface. Gravitational lensing has been measured by previous CMB experiments, with Planck's 42 σ detection being the current best full-sky lensing map. We present an enhanced LiteBIRD lensing map by extending the CMB multipole range and including the minimum-variance estimation, leading to a 49 to 58 σ detection over 80 % of the sky, depending on the final complexity of polarized Galactic emission. The combination of Planck and LiteBIRD will be the best full-sky lensing map in the 2030s, providing a 72 to 78 σ detection over 80 % of the sky, almost doubling Planck's sensitivity. Finally, we explore different applications of the lensing map, including cosmological parameter estimation using a lensing-only likelihood and internal delensing, showing that the combination of both experiments leads to improved constraints. The combination of Planck + LiteBIRD will improve the S ₈ constraint by a factor of 2 compared to Planck, and Planck + LiteBIRD internal delensing will improve LiteBIRD's tensor-to-scalar ratio constraint by 6 %. We have tested the robustness of our results against foreground models of different complexity, showing that improvements remain even for the most complex foregrounds.

Models in which a subcomponent of dark matter interacts with dark radiation have been proposed as a solution to the Hubble tension. In this framework, the interacting subcomponent of dark matter is in thermal equilibrium with the dark radiation in the early universe, but decouples from it around the time of matter-radiation equality. We study this general class of models and evaluate the quality of fit to recent cosmological data on the cosmic microwave background (from Planck 2018 and ACT DR6), baryon acoustic oscillations, large-scale structure, supernovae type Ia, and Cepheid variables. We focus on three benchmark scenarios that differ in the rate at which the dark matter decouples from the dark radiation, resulting in different patterns of dark acoustic oscillations. Fitting without ACT DR6 data, we find that all three scenarios significantly reduce the Hubble tension relative to $Λ$CDM, with an exponentially fast decoupling being the most preferred. The tension is reduced to less than $2 \, σ$ in fits that don't include the SH0ES collaboration results as part of the data and to less than $1 \, σ$ when these are included. When ACT DR6 data is included, the fit is significantly worsened. We find that the largest $H_0$ value at the $95 \%$ confidence region is $70.1$ km/s/Mpc without the SH0ES data, leading to only a mild reduction in the tension. This increases to $72.5$ km/s/Mpc, corresponding to a reduction in the tension to less than $3 \, σ$, if the SH0ES results are included in the fit.

We study gravitational back-reaction within the Page-Wootters formulation of quantum mechanics by treating time as a quantum degree of freedom. Our model introduces a distinction between global "coordinate time," represented as a relational quantum observable, and "proper time," measured by internal quantum degrees of freedom of physical systems. By coupling mass-energy with coordinate time through a Wheeler-DeWitt-like constraint, we demonstrate the natural emergence of gravitational time dilation. In the presence of a massive object this agrees with time dilation in a Schwarzchild metric at leading order if the interaction strength is taken to be representative of the gravitational coupling G. Additionally, when two particles independently couple to the time coordinate, a Newtonian gravitational interaction arises in the low-energy limit, showing how gravitational potential can emerge from non-interacting quantum systems. Our approach also reveals renormalization features, potentially softening high-energy divergences and suggesting that particles in superposition might introduce quantum corrections to gravitational time dilation.

We compute the partition function for the <inline-formula><mml:math><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:math></inline-formula> spinning particle, including pictures and the large Hilbert space, and show that it counts the dimension of the Becchi-Rouet-Stora-Tyutin cohomology in two- and four-dimensional target space. We also construct a quadratic action in the target space. Furthermore, we find a consistent interaction as a derived bracket based on the associative product of worldline fields, leading to an interacting theory of multiforms in space-time. Finally, we comment on the equivalence of the multiform theory with a Dirac fermion. We also identify the chiral anomaly of the latter with a Hodge anomaly for the multiform theory, which manifests itself as a deformation of the gauge fixing.

Red supergiants (RSGs), which are progenitors of hydrogen-rich Type II supernovae (SNe), have been known to pulsate, both from observations and theory. The pulsations can be present at core collapse and affect the resulting SN. However, SN light curve models of such RSGs commonly use hydrostatic progenitor models and ignore pulsations. Here, we model the final stages of a 15 M_⊙ RSG and self-consistently follow the hydrodynamical evolution. We observe the growth of large-amplitude radial pulsations in the envelope. After a transient phase in which the envelope restructures, the pulsations settle to a steady and periodic oscillation with a period of 817 days. We show that they are driven by the κγ mechanism, which is an interplay between changing opacities and the release of recombination energy of hydrogen and helium. This leads to complex and incoherent expansion and contraction in different parts of the envelope, which greatly affects the SN progenitor properties, including its location in the Hertzsprung-Russell diagram. We simulate SN explosions of this model at different pulsation phases. Explosions in the compressed state result in a flat light curve (Type II-P). In contrast, the SN light curve in the expanded state declines rapidly, reminiscent of a Type II-L SN. For cases in between, we find light curves with various decline rates. Features in the SN light curves are directly connected to features in the density profiles. These are, in turn, linked to the envelope ionization structure, which is the driving mechanism of the pulsations. We predict that some of the observed diversity in Type II SN light curves can be explained by RSG pulsations. For more massive RSGs, we expect stronger pulsations that might even lead to dynamical mass ejections of the envelope and to an increased diversity in SN light curves.

We present simulations of the supernova-driven turbulent interstellar medium (ISM) in a simulation domain of volume <inline-formula><tex-math>$(256\, {\rm pc})^3$</tex-math></inline-formula> within which we resolve the formation of protostellar accretion discs and their stellar cores to spatial scales of <inline-formula><tex-math>$\sim 10^{-4}$</tex-math></inline-formula> au, using the moving-mesh code AREPO. We perform simulations with no magnetic fields, ideal magnetohydrodynamics (MHD) and ambipolar diffusion, and compare the resulting first Larson cores and their associated structures, including the accretion discs, their location within the larger-scale structure and the streamers connecting these. We find that discs of sizes <inline-formula><tex-math>$10{\small --}100\, {\rm au}$</tex-math></inline-formula> form early in the simulations without magnetic fields, while there are no discs larger than 10 au with ideal MHD. Ambipolar diffusion causes large discs to form in a subset of cases (two out of six cores), and generally reduces the strength of outflows, which are seen to play a central role. When they are able to carry away significant angular momentum, they prevent the formation of a rotationally supported disc. Magnetic fields strengths grow from <inline-formula><tex-math>$0.1 {\small --} 1$</tex-math></inline-formula> mG in the protostellar core to more than 10 G in the first Larson core in all simulations with ideal MHD. The rotationally supported discs which form can have rotation speeds <inline-formula><tex-math>$> 1$</tex-math></inline-formula> km s<inline-formula><tex-math>$^{-1}$</tex-math></inline-formula> even out to further than 100 au from the centre, become gravitationally unstable and form complex spiral substructures with Toomre <inline-formula><tex-math>$Q < 1$</tex-math></inline-formula>. We conclude that the impact of magnetic fields and non-ideal MHD on the formation of protostellar discs is substantial in realistic formation scenarios from the turbulent ISM.

We present a systematic method for analytically computing time-dependent observables for a relativistic probe particle in Coulomb and Schwarzschild backgrounds. The method generates expressions valid both in the bound and unbound regimes, namely bound-unbound universal expressions. To demonstrate our method we compute the time-dependent radius and azimuthal angle for relativistic motion in a Coulomb background (relativistic Keplerian motion), as well as the electromagnetic field radiated by a relativistic Keplerian source. All of our calculations exhibit bound-unbound universality. Finally, we present an exact expression for the semi-classical wave function in Schwarzschild. The latter is crucial in applying our method to any time-dependent observable for probe-limit motion in Schwarzschild, to any desired order in velocity and the gravitational constant G.

Dusty, submillimeter-selected galaxies without optical counterparts contribute a non-negligible fraction of the star formation in the early universe. However, such a population is difficult to detect through classical optical/UV-based surveys. We report the serendipitous discovery of such an optically dark galaxy, behind the quadruply-lensed $z=2.56$ quasar, H1413+117, offset to the north by 6\arcsec. From $^{12}$CO $J=4$--3, $J=6$--5, and part of the $J=13$--12 transitions, which all spatially coincide with a compact submillimeter continuum emission, we determine an unambiguous spectroscopic redshift, $z=3.386\pm 0.005$. This galaxy has a molecular mass $M_{\rm mol} \sim 10^{11}$ M$_\odot$ and a black hole mass $M_{\rm BH} \sim 10^{8}$ M$_\odot$, estimated from $^{12}$CO $J=4$--3 and archival {\it Chandra} X-ray data ($L_{\rm 2-10,keV} \sim 4 \times 10^{44}$\,erg\,s$^{-1}$), respectively. We also estimate a total infrared luminosity of $L_{\rm FIR} = (2.8\pm{2.3}) \times 10^{12}$ L$_\odot$ and a stellar mass of $M_* \lesssim 10^{11}$ M$_{\odot}$, from spectral energy distribution fitting. According to these simple mass estimations, this gas-rich and X-ray bright galaxy might be in a transition phase from starburst to quasar offering a unique case for studying galaxy-black hole co-evolution under extremely dusty conditions.

We identify a new production channel for quantum chromodynamics (QCD) axions in supernova environments that contributes to axion emissivity for all models solving the strong <inline-formula><mml:math><mml:mi>C</mml:mi><mml:mi>P</mml:mi></mml:math></inline-formula> problem. This channel arises at tree-level from a shift-symmetry-breaking operator constructed at next-to-leading order in chiral perturbation theory. In scenarios where model-dependent derivative couplings to nucleons are absent, this sets the strongest model-independent constraint on the axion mass, improving on existing bounds by two orders of magnitude.