Detailed knowledge of the radiation environment in space is an indispensable prerequisite for space missions in low Earth orbit and beyond. The RadMap Telescope is a compact radiation monitor that can characterize the radiation environment aboard spacecraft and determine the biologically relevant dose received by astronauts. Its main sensor is a tracking calorimeter made from 1024 scintillating-plastic fibers of alternating orientation and silicon photomultipliers. It allows the three-dimensional tracking and identification of cosmic-ray nuclei by measurement of their energy-deposition profiles.

The properties of nuclei traversing the detector are reconstructed using a neural-network-based analysis framework. In this contribution, we describe the three consecutive convolutional networks that we use to determine the track parameters, charge, and initial kinetic energy of each nucleus as well as the challenges of a network-based analysis approach. We demonstrate the capabilities of our framework with networks trained and evaluated on simulated data and show that the achieved performance is in agreement with the requirements of radiation monitoring. Finally, we discuss the significance of our results and the limitations of both the analysis framework and the detector.

The RadMap Telescope is a compact instrument designed to characterize the primary spectrum of cosmic-ray nuclei and the secondary radiation field created by their interaction with the shielding of spacecraft. Its main purpose is to precisely monitor the radiation exposure of astronauts, and it is the first instrument with a compact form factor that can measure both the charge and energy of individual nuclei with energies up to several GeV per nucleon. This capability is enabled by a tracking calorimeter made from scintillating-plastic fibers, which can record the energy-loss profile of particles in three dimensions and with nearly omnidirectional sensitivity. We present first results from the RadMap Telescope's first orbital deployment on the International Space Station between April 2023 and January 2024.

The goal of this work is to estimate the Hubble constant <inline-formula><tex-math>$H_0$</tex-math></inline-formula> through the time-delay cosmographic study of the quadruply lensed, variable quasi-stellar objects (QSO) SDSSJ1433+6007. We combine multifilter, archival Hubble Space Telescope data for lens modelling with a dedicated 3-yr long time-delay monitoring campaign using the 2.1 m Fraunhofer telescope at the Wendelstein Observatory. The lens modelling is performed with the public LENSTRONOMY PYTHON package individually for the infrared data, utilizing the higher resolution of the optical data to constrain image positions a priori. This approach revealed two luminous contaminants in one of the near-infrared exposures, which would bias the lensing potentials and cosmological inference if left unaccounted. After masking these contaminants, we repeated the modelling and combined the lens posteriors, obtaining a constraint on the Fermat potential with a statistical uncertainty of <inline-formula><tex-math>$2.6\, {{\rm per\ cent}}$</tex-math></inline-formula>. The g'-band Wendelstein light-curve data are reduced and then analysed using a free-knot spline fitting method implemented in the public PYTHON PYCS3 tools, accounting for microlensing correction. We obtain a precision of <inline-formula><tex-math>$6.5\, {{\rm per\ cent}}$</tex-math></inline-formula> for the time delays between the QSO images. By combining the posteriors for the Fermat potential differences and time delays, and assuming a flat Lambda-cold dark matter cosmology, we infer a Hubble constant of <inline-formula><tex-math>$H_0=71.7^{+3.9}_{-3.6}\, {\rm{km}}\,{\mathrm{Mpc}^{-1}~\mathrm{s}^{-1}}$</tex-math></inline-formula>, achieving <inline-formula><tex-math>$5.3\, {{\rm per\ cent}}$</tex-math></inline-formula> purely statistical uncertainty for this single system. Complementary observations and further study are required to address the systematic errors fully.

The obliquity between the stellar spin axis and the planetary orbit, detected via the Rossiter-McLaughlin (RM) effect, is a tracer of the formation history of planetary systems. While obliquity measurements have been extensively applied to hot Jupiters and short-period planets, they remain rare for cold and long-period planets due to observational challenges, particularly their long transit durations. We report the detection of the RM effect for the 19-hour transit of HIP 41378 f, a temperate giant planet on a 542-day orbit, observed through a worldwide spectroscopic campaign. We measured a slight projected obliquity of 21 ± 8° and a significant 3D spin-orbit angle of 52 ± 6°, based on the measurement of the stellar rotation period. HIP 41378 f is part a transiting system of five planets with planets close to mean motion resonances. The observed misalignment likely reflects a primordial tilt of the stellar spin axis relative to the protoplanetary disk, rather than dynamical interactions. HIP 41378 f is the first non-eccentric long-period planet (P>100 days) observed with the RM effect, opening new constraints on planetary formation theories. This observation should motivate the exploration of planetary obliquities across a longer range of orbital distances through international collaboration.

We investigate the influence of supernova (SN) feedback on the satellites of elliptical host galaxies using hydrodynamic simulations. Utilizing a modified version of the GADGET-3 code, we perform cosmological zoom-in simulations of 11 elliptical galaxies with stellar masses in the range 10¹¹M_⊙ < M_* < 2 × 10¹¹M_⊙. We conduct two sets of simulations with identical initial conditions: a fiducial model, which includes a three-phase SN mechanical wind, and a weak SN feedback model, where nearly all SN energy is released as thermal energy with a reduced SN wind velocity. Our comparison shows minimal differences in the elliptical host galaxies, but significant variations in the physical properties of satellite galaxies. The weak SN feedback model produces a larger number of satellite galaxies compared to the fiducial model, and significantly more than observed. For satellite galaxies with stellar masses above 10⁸M_⊙, the weak SN feedback model generates approximately 5 times more satellites than observed in the Extending the Satellites Around Galactic Analogs Survey (or xSAGA) survey. Most of these overproduced satellites have small stellar masses, below 10¹⁰M_⊙. Additionally, satellites in the weak SN feedback model are about 3.5 times more compact than those observed in the SAGA survey and the fiducial model, with metallicities nearly 1 dex higher than observed values. In conclusion, the satellite galaxies in the fiducial model, which includes mechanical SN feedback, exhibit properties that more closely align with observations. This underscores the necessity of incorporating both mechanical active galactic nuclei and SN feedback to reproduce the observed properties of elliptical galaxies and their satellites in simulations.

Context. Our knowledge of the initial conditions of terrestrial planet formation is mainly based on the study of protoplanetary disks around nearby isolated low-mass stars. However, most young stars and therefore planetary systems form in high-mass star-forming regions and are exposed to ultraviolet radiation, affecting the protoplanetary disk. These regions are located at large distances and only now with JWST has it become accessible to study the inner disks surrounding young stars. Aims. We present the eXtreme UV Environments (XUE) program, which provides the first detailed characterization of the physical and chemical properties of the inner disks around young intermediate-mass (1–4 M_⊙) stars exposed to external irradiation from nearby massive stars. We present high-signal-to-noise MIRI-MRS spectroscopy of 12 disks located in three subclusters of the high-mass star-forming region NGC 6357 (d ~ 1690 pc). Methods. Based on their mid-infrared spectral energy distribution, we classified the XUE sources into Group I and II based on the Meeus scheme. We analyzed their molecular emission features, and compared their spectral indices and 10 μm silicate emission profiles to the ones of nearby Herbig and intermediate T Tauri (IMTT) disks. Results. The XUE program provides the first detailed characterization of the rich molecular inventory in IMTT disks, including water, CO, CO₂, HCN, and C₂H₂. In the XUE sample, the detected emission likely originates from within 10 au, although this inner disk origin may not be typical for all externally irradiated disks. Despite being more massive, the XUE stars host disks with a molecular richness comparable to isolated T Tauri systems. The spectral indices are also consistent with similar-mass stars in nearby regions. The 10 μm silicate features in the XUE sample exhibit lower F_11.3/F_9.8 ratios at a given F_peak, suggesting that the disk surfaces may be dominated by smaller grains compared to nearby disks. However, uncertainties in extinction prevent us from drawing firm conclusions about their inner disk properties. The majority of disks display water emission from the inner disk, suggesting that even in these extreme environments rocky planets can form in the presence of water. Only one object shows PAH emission, contrasting with the higher PAH detection rates in IMTT surveys from lower-UV environments. Conclusions. The absence of strong line fluxes and other irradiation signatures suggests that the XUE disks have been truncated by external UV photons. However, this truncation does not appear to significantly impact the chemical richness of their inner regions. These findings indicate that even in extreme environments, IMTT disks can retain the ingredients necessary for rocky planet formation, comparable to the ones of lower-mass T Tauri disks in low-mass star-forming regions.

Context. Supergiant B[e] (sgB[e]) stars are exceptionally rare objects, with only a select number of confirmed examples in the Milky Way. The evolutionary pathways leading to the sgB[e] phase remain largely debated, highlighting the need for additional observations. The sgB[e] star Wd1-9, located in the massive cluster Westerlund 1 (Wd1), is enshrouded in a dusty cocoon – likely the result of past eruptive activity – leaving its true nature enigmatic. Aims. We present the most detailed X-ray study of Wd1-9 to date, using X-rays that pierce through its cocoon with the aim of uncovering its nature and evolutionary state. Methods. We utilised 36 Chandra observations of Wd1 from the 'Extended Westerlund 1 and 2 Open Clusters Survey' (EWOCS), plus eight archival datasets, totalling 1.1 Ms. We used this dataset to investigate long-term variability and periodicity in Wd1-9, and analysed X-ray colours and spectra over time to uncover patterns that shed light on its nature. Results. Wd1-9 exhibits significant long-term X-ray variability, within which we identify a strong ∼14-day periodic signal. We interpret this as the orbital period, marking the first period determination for the system. The X-ray spectrum of Wd1-9 is thermal and hard (kT ∼ 3.0 keV), resembling the spectra of bright Wolf-Rayet (WR) binaries in Wd1, while a strong Fe emission line at 6.7 keV indicates hot plasma from a colliding-wind X-ray binary. Conclusions. Wd1-9, with evidence of past mass loss, circumbinary material, a hard X-ray spectrum, and a newly detected 14-day period, displays all the hallmarks of a binary – likely a WR+OB – that recently underwent early Case B mass transfer. Its sgB[e] classification is likely phenomenological, reflecting emission from the dense circumbinary material. This places Wd1-9 in a rarely observed phase, possibly revealing a newly formed WN star, bridging the gap between immediate precursors and later evolutionary stages in Wd1.

Motivated by JWST observations of dense, clumpy, and clustered high-redshift star formation, we simulate the hierarchical assembly of nine <inline-formula><tex-math>$M_{\mathrm{cl}}={10^6}\:\mathrm{M_\odot }$</tex-math></inline-formula> star clusters using the BIFROST N-body code. Our low-metallicity models (<inline-formula><tex-math>$0.01Z_\odot$</tex-math></inline-formula>) with post-Newtonian equations of motion for black holes include evolving populations of single, binary, and triple stars. Massive stars grow by stellar collisions and collapse into intermediate-mass black holes (IMBHs) up to <inline-formula><tex-math>$M_\mathrm{\bullet }\sim {6200}\:\mathrm{M_\odot }$</tex-math></inline-formula>, stellar multiplicity boosting the IMBH masses by a factor of 2–3. The IMBHs tidally disrupt (TDE) <inline-formula><tex-math>$\sim 50$</tex-math></inline-formula> stars in 10 Myr with peak TDE rates up to <inline-formula><tex-math>$\Gamma \sim 5\times 10^{-5}$</tex-math></inline-formula> <inline-formula><tex-math>$\rm{yr}^{-1}$</tex-math></inline-formula> per cluster. These IMBHs are natural seeds for supermassive black holes (SMBHs) and the hierarchical assembly frequently leads to <inline-formula><tex-math>$>2$</tex-math></inline-formula> SMBH seeds per cluster and their rapid mergers (<inline-formula><tex-math>$t< 10$</tex-math></inline-formula> Myr). We propose that a gravitational wave (GW)-driven merger of IMBHs with <inline-formula><tex-math>${1000}\:\mathrm{M_\odot } \lesssim M_\bullet \lesssim {10\,000}\:\mathrm{M_\odot }$</tex-math></inline-formula> with comparable masses is a characteristic GW fingerprint of SMBH seed formation at redshifts <inline-formula><tex-math>$z>10$</tex-math></inline-formula>, and IMBH formation in similar environments at lower redshifts. Massive star clusters provide a unique environment for the early Universe GW studies for the next-generation GW observatories including the Einstein Telescope and the Laser Interferometer Space Antenna.

A crucial ingredient affecting fast neutrino flavor conversion in core-collapse supernovae (SNe) is the shape of the angular distribution of the electron-neutrino lepton number (ELN). The presence of an ELN crossing signals favorable conditions for flavor conversion. However, the dependence of ELN crossings on the SN properties is only partially understood. We investigate a suite of 12 spherically symmetric neutrino-hydrodynamics simulations of the core collapse of a SN with a mass of <inline-formula><mml:math><mml:mrow><mml:mn>18.6</mml:mn><mml:msub><mml:mrow><mml:mi>M</mml:mi></mml:mrow><mml:mrow><mml:mo>⊙</mml:mo></mml:mrow></mml:msub></mml:mrow></mml:math></inline-formula>; each model employs different microphysics (i.e., three different nuclear equations of state, with and without muon creation) and includes or not a mixing-length treatment for proto-neutron star convection. We solve the Boltzmann equations to compute the neutrino angular distributions relying on static fluid properties extracted from each of the SN simulations in our suite for six selected postbounce times. We explore the dependence of the ELN distributions on the SN microphysics and proto-neutron star convection. We find that the latter shifts the proto-neutron star radius outward, favoring the appearance of ELN crossings at larger radii. On the other hand, muon creation causes proto-neutron star contraction, facilitating the occurrence of ELN crossings at smaller radii. These effects mildly depend on the nuclear equation of state. Our findings highlight the subtle impact of the SN microphysics, proto-neutron star convection, and neutrino transport on the ELN angular distributions.

In the standard formation models of terrestrial planets in the solar system and close-in super-Earths in non-resonant orbits recently discovered by exoplanet observations, planets are formed by giant impacts of protoplanets or planetary embryos after the dispersal of protoplanetary disk gas in the final stage. This study aims to theoretically clarify a fundamental scaling law for the orbital architecture of planetary systems formed by giant impacts. In the giant impact stage, protoplanets gravitationally scatter and collide with one another to form planets. Using {\em N}-body simulations, we investigate the orbital architecture of planetary systems formed from protoplanet systems by giant impacts. As the orbital architecture parameters, we focus on the mean orbital separation between two adjacent planets and the mean orbital eccentricity of planets in a planetary system. We find that the orbital architecture is determined by the ratio of the two-body surface escape velocity of planets $v_\mathrm{esc}$ to the Keplerian circular velocity $v_\mathrm{K}$, $k$ = The mean orbital separation and eccentricity are about $2 ka$ and $0.3 k$, respectively, where $a$ is the system semimajor axis. With this scaling, the orbital architecture parameters of planetary systems are nearly independent of their total mass and semimajor axis.

We utilize the Magneticum suite of hydrodynamical simulations to investigate the formation and evolution of cosmic voids from $z = 5.04$ to present day, using cold dark matter and (sub-) halo tracers in high-density samples. This includes the evolution of their global properties, such as size, shape, inner density, and average density, as well as their radial density profiles. Our results provide several key conclusions for void analyses in modern surveys. We demonstrate that a relative size framework is required, mitigating methodological selection effects and revealing the true physical evolution of densities around halo-defined voids. This necessity arises from our findings that a void's properties are more fundamentally tied to its rank within its contemporary population than to its absolute size. Using this framework, we show that the evolution of halo voids stabilizes at redshifts below $z \simeq 1$, driven primarily by cosmic expansion rather than ongoing halo formation. We further find that the matter evolution around these stable voids is remarkably well-described by linear growth theory, with deviations appearing as non-linear growth on small scales and suppressed growth in the largest voids, potentially driven by the influence of dark energy. This late-time stability and the predictable evolution confirm voids as pristine laboratories for probing the nature of dark energy with upcoming surveys.

(Sub-)millimetre single-dish telescopes feature faster mapping speeds and access larger spatial scales than their interferometric counterparts. However, atmospheric fluctuations tend to dominate their signals and complicate recovery of the astronomical sky. Here we develop a framework for Gaussian process-based sky reconstruction and separation of the atmospheric emission from the astronomical signal based on Numerical Information Field Theory (\texttt{NIFTy}). To validate this novel approach, we use the \textit{maria} software to generate synthetic time-ordered observational data mimicking the MUSTANG-2 bolometric array. This approach leads to significantly improved sky reconstructions versus traditional methods.

The core of a massive star (M > 8 Msun) eventually collapses. This implosion usually triggers a supernova (SN) explosion that ejects most of the stellar envelope and leaves behind a neutron star (NS) with a mass of up to about 2 Msun. Sometimes the explosion fails and a black hole forms instead. The NS radiates its immense binding energy (some 10% of its rest mass or $2-4\times10^{53}$ erg) almost entirely as neutrinos and antineutrinos of all flavors with typical energies of some 10 MeV. This makes core-collapse SNe the most powerful neutrino factories in the Universe. Such a signal was observed once - with limited statistics - from SN 1987A in the Large Magellanic Cloud. Today, however, many large neutrino detectors act as SN observatories and would register a high-statistics signal. A future Galactic SN, though rare (1-3 per century), would produce a wealth of astrophysical and particle-physics information, including possible signatures for new particles. Neutrinos are key to SN dynamics in the framework of the Bethe-Wilson delayed explosion paradigm. After collapse, they are trapped in the core for a few seconds, forming a dense neutrino plasma that can exhibit collective flavor evolution caused by the weak interaction, a subject of intense theoretical research.

We embed the perturbative Fock state of the Yang-Mills BV-multiplet in the vertex operator algebra of the path-integral for the $\mathcal{N}=2$ supersymmetric world line and evaluate the pull-back of the latter to an integral form on supermoduli space. Choosing a suitable Poincaré dual on the latter, we show that this integral form describes an extension of Yang-Mills theory. Upon projection back to the Fock space, we recover the Yang-Mills action from the world line. This furthermore gives an a priori justification for the construction of Yang-Mills equations of motion as emerging from deformations of the BRST differential.

We study the implications of non-invertible chiral symmetry in a four-dimensional U(1) gauge theory coupled to massless fermions with electromagnetic $SL(2,\mathbb{Z})$ 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 non-invertible 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 non-local charged state with nonzero pairwise helicity.

This is a pedagogical review of some recent progress in rigorously proving chiral symmetry breaking in a class of QCD-like theories that closely resemble the real-world QCD, namely the $SU(N_c)$ Yang-Mills theory coupled to $N_f$ flavors of massless quarks in the fundamental representation. Based on 't Hooft anomaly matching and persistent mass conditions, a general no-go theorem is formulated: assuming that the theory flows in the infrared to a fully color-screened, infrared-free phase described by color-singlet hadrons, symmetry and anomaly constraints necessarily imply spontaneous chiral symmetry breaking; conversely, any phase with unbroken chiral symmetry must retain unscreened color charges, thereby ruling out a fully color-singlet hadron description in the infrared. While these results have been widely assumed, the recent developments reviewed here establish them with a new level of rigor. The persistent mass condition, carefully formulated here, plays a central role, just as it does in the Vafa-Witten theorem on unbroken vectorlike symmetries.

We study the physics potential of heavy QCD axions at high-energy muon colliders. Unlike typical axion-like particles, heavy QCD axions solve the strong CP problem with phenomenology driven by the anomalous gluon ($aG\widetilde G$) couplings. Several ultraviolet scenarios are presented in which QCD axions with TeV-scale masses and decay constants arise consistently with a solution to both the strong CP problem and the axion quality problem. We perform a detailed collider analysis for both a 3 and 10~TeV muon collider, focusing on hadronic axion decays that gives rise to a dijet-resonance signature. Our projections for the axion discovery reach in the multi-TeV mass range demonstrate that a muon collider can significantly extend sensitivity to heavy QCD axions compared to existing experiments.

A first-order phase transition could occur in the late universe when vacuum energy begins dominating the energy density ($z \lesssim 0.3$) and convert some latent heat into other forms such as invisible radiation. This generic possibility also has concrete motivation in particle physics models which invoke a multitude of vacua to address theoretical puzzles. The naïve constraint on such an event comes from measurements of the Hubble expansion rate, but this can only probe transitions involving $\mathcal{O}(10)\%$ of the dark energy. In this work, we show that significantly tighter constraints appear when accounting for phase transition fluctuations affecting CMB photon propagation anisotropically, akin to the integrated Sachs-Wolfe effect. For instance, if a completed phase transition has $β/H_\star\lesssim 25$, current CMB data limits the associated vacuum energy released to less than $1\%$ of the dark energy. A transition to negative vacuum energy (quasi-anti-de Sitter) is allowed only for $β/H_\star \gtrsim 300$. For $β/H_\star \lesssim 500$, the universe will not crunch for at least $14$ Gyr.

[abridged] Accurately accounting for the AGN phase in galaxy evolution requires a large, clean AGN sample. This is now possible with SRG/eROSITA. The public Data Release 1 (DR1, Jan 31, 2024) includes 930,203 sources from the Western Galactic Hemisphere. 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 multiwavelength data. This paper presents the identification and classification of optical and infrared counterparts to eRASS1 sources 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. Within the LS10 footprint, all 656,614 eROSITA/DR1 sources have at least one possible optical counterpart; about 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 surveys 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 identify approximately 18,000 Gaia and 55,000 CatWISE2020 extragalactic sources. We release 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 empower researchers to build AGN samples tailored for completeness and purity, accelerating the hunt for the Universe most energetic engines.

Galaxies with high star-formation rate surface densities often host large-scale outflows that redistribute energy, momentum, and baryons between the interstellar medium and the halo, making them a key feedback channel regulating galaxy evolution. Despite their importance, the driving physics behind galactic outflows and their interaction with the surrounding halo is yet to be fully understood. In particular, the influence of a pre-existing reservoir of cosmic rays (CRs) in galaxy halos has not been clearly established. We determine the conditions required to launch outflows in the presence of halo CRs and investigate how CR pressure gradients modify outflow speeds. We find that CR halos suppress the development of large-scale, CR-driven winds and redirect CR feedback toward local recycling flows. Slow outflows are therefore more likely in young galaxies lacking extended CR halos, while fast winds in intense starbursts are dominated by momentum injection and largely unaffected by halo CRs.

Dense young star clusters (YSCs) are ideal environments for dynamical interactions between stars and stellar mass black holes (BHs). In such dense environments, stars can undergo close encounters with BHs and fall within their tidal radius, resulting in micro-tidal disruption events (micro-TDEs), transient phenomena with potential multi-messenger signatures. We performed a suite of direct N-body simulations using the PETAR code, to which we implemented new prescriptions for modeling micro-TDEs. We constructed a set of realistic YSC models including primordial binaries, based on the observed Milky Way population. Our simulations incorporate stellar and binary evolution, supernova kicks, and stellar winds using the BSE code, and account for the Galactic tidal field via the GALPY library. We identify three dynamical channels for micro-TDE production: single star-single BH encounters, binary-mediated interactions (including supernova-kick triggers), and interactions involving higher-order multiple systems such as hierarchical triples and quadruples, as well as chaotic few-body interactions. Multiple encounters are the most efficient production channel, which dominates the total rate: 350-450 Gpc$^{-3}$ yr$^{-1}$. Micro-TDEs from YSCs are expected to be detectable by upcoming surveys, particularly the Legacy Survey of Space and Time, with detection rates potentially up to hundreds per year. The gravitational wave (GW) signals expected from micro-TDEs peak in the deci-Hertz band, making them accessible to future instruments such as the Lunar Gravitational Wave Antenna and the Deci-Hertz Interferometer Gravitational-wave Observatory. Micro-TDEs emerge as promising multi-messenger sources, potentially offering unique insights into star cluster dynamics, stellar collisions, and the population of dormant stellar-mass BHs, through both electromagnetic and GW observations.

We further scrutinize the evidence for a recently suggested pseudo-scalar particle, the electroweak $η_{\rm w}$-meson. Its existence is demanded by matching the removal of the weak vacuum angle $θ_{\rm w}$ by the anomalous $B+L$ - symmetry with a massive pole in the topological susceptibility of the vacuum. We specifically focus on the possibility of the emergence of $η_{\rm w}$ as a collective excitation of the phase of the condensate of the 't Hooft fermion determinant, generated by the electroweak instantons, which breaks the $B+L$ - symmetry spontaneously. We argue that the generation of the 't Hooft vertex is in one-to-one correspondence with its non-zero vacuum expectation value which is cutoff insensitive. We outline certain puzzles about the nature of the emergent $η_{\rm w}$ which require further investigations.

A five-dimensional minimal supergravity theory coupled to vector and hypermultiplets is specified by a set of trilinear couplings, given by an intersection form $C_{IJK}$, and gravitational couplings specified by an integer-valued vector $a_I$ and is consistent when these data define an integral cubic form. For every Calabi-Yau threefold reduction of M-theory, this condition is satisfied automatically. Via suitable redefinitions of the basis of 5D vectors, this is also shown to be the case for the circle reductions of six-dimensional anomaly-free (1,0) theories. When the 6D theory has a $\mathbb{Z}_k$ gauge symmetry, we point out that the consistency of the circle reduction with nontrivial $\mathbb{Z}_k$ holonomy is closely related to 6D constraints derived by Monnier and Moore. These constraints are extended to semidirect products with continuous gauge groups $\mathbb{Z}_k \ltimes G$ and CHL-like circle compactifications. When $\mathbb{Z}_k$ acts on anti-self-dual tensor fields of 6D supergravity, there should be a nontrivial action of holonomy on the topological Green-Schwarz terms.

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 $SU(N)$-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 time-scale 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.

We study a family of generalized hypergeometric integrals defined on punctured Riemann surfaces of genus g. These integrals are closely related to g-loop string amplitudes in chiral splitting, where one leaves the loop-momenta, moduli and all but one puncture un-integrated. We study the twisted homology groups associated to these integrals, and determine their intersection numbers. We make use of these homology intersection numbers to write a double-copy formula for the "complex" version of these integrals -- their closed-string analogues. To verify our findings, we develop numerical tools for the evaluation of the integrals in this work. This includes the recently introduced Enriquez kernels -- integration kernels for higher-genus polylogarithms.

MACS J0138-2155 is the only known cluster to strongly lens two supernovae (SNe), Requiem and Encore, from the same host galaxy at z=1.949. We present seven independent mass models of the galaxy cluster built using six software packages. By conducting a blind analysis (no exchanges of results between modeling teams), we quantified uncertainties due to modeling and software. Through HST, JWST and MUSE observations, we assembled high-quality data products, including eight "gold" lensed image systems consisting of 23 images with secure spectroscopic redshifts, and one "silver" system with a likely redshift value. Restricting to the gold images, we obtain overall consistent model predictions of the positions, magnifications and time delays of SN Encore and SN Requiem images, especially for models with $χ^2 \leq 25$. We predict the appearance of the next images of SNe Encore and Requiem with a time delay of >~3000 days and of ~3700 to 4000 days, respectively, based on a fiducial cosmological model of $H_0 = 70 {\rm\ km\ s^{-1}\ Mpc^{-1}}$ and $Ω_{\rm m} = 0.3$. We obtain relations between $H_0$ and the time delays of SNe Encore and Requiem. In particular, for $H_0 = 73 {\rm\ km\ s^{-1}\ Mpc^{-1}}$, the four lowest $χ^2$ models predict SN Requiem to reappear in ~Apr-Dec 2026; for $H_0 = 67 {\rm\ km\ s^{-1}\ Mpc^{-1}}$, in ~Mar-Nov 2027. Using the newly measured time delay between the two detected images of SN Encore by Pierel et al. (submitted) and our mass models, we jointly infer $H_0 = {\rm 66.9^{+11.2}_{-8.1}\ km\ s^{-1}\ Mpc^{-1}}$, where the uncertainty is dominated by that of the time delay. The long delays of the next-appearing SN Requiem and SN Encore images provide excellent opportunities to measure $H_0$ with an uncertainty of 2-3%. Our mass models form the basis for cosmological inference from this unique lens cluster with two strongly lensed SNe. (Abridged)

The substantial data volumes encountered in modern particle physics and other domains of fundamental physics research allow (and require) the use of increasingly complex data analysis tools and workflows. While the use of machine learning (ML) tools for data analysis has recently proliferated, these tools are typically special-purpose algorithms that rely, for example, on encoded physics knowledge to reach optimal performance. In this work, we investigate a new and orthogonal direction: Using recent progress in large language models (LLMs) to create a team of agents -- instances of LLMs with specific subtasks -- that jointly solve data analysis-based research problems in a way similar to how a human researcher might: by creating code to operate standard tools and libraries (including ML systems) and by building on results of previous iterations. If successful, such agent-based systems could be deployed to automate routine analysis components to counteract the increasing complexity of modern tool chains. To investigate the capabilities of current-generation commercial LLMs, we consider the task of anomaly detection via the publicly available and highly-studied LHC Olympics dataset. Several current models by OpenAI (GPT-4o, o4-mini, GPT-4.1, and GPT-5) are investigated and their stability tested. Overall, we observe the capacity of the agent-based system to solve this data analysis problem. The best agent-created solutions mirror the performance of human state-of-the-art results.

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 (EMRI) 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.

We propose a new model to explain the KM3NeT neutrino event through a low reheating scenario with a suppression in the GW spectrum originating from cosmic string networks. To achieve this, we extend the SM gauge sector by an abelian gauge symmetry and a singlet scalar. Once the abelian gauge symmetry spontaneously breaks, the extra gauge boson acquires mass and becomes a suitable Dark Matter (DM) candidate. Due to the kinetic mixing with the hypercharge gauge group, DM can decay into SM particles. To explain the KM3NeT signal, we need $\mathcal{O}(100)$ PeV DM, which can be produced in the correct order of DM density in a low reheating scenario. In this scenario, the overabundance issue of heavy DM can be tackled by diluting its abundance through the continuous injection of entropy when the matter-like inflaton decays into the SM bath. Using the low reheating scenario, we can obtain the correct value of DM density both for freeze-out and freeze-in mechanisms for super-heavy DM. Moreover, we have studied the Gravitational Waves (GWs) produced from cosmic strings, which fall within the detectable range of future proposed GW experiments. Additionally, the dominance of a quadratic inflaton potential before the reheating temperature changes the temperature-scale factor relation, which suppresses the GW spectrum at higher frequencies. Choosing an arbitrarily low reheating temperature provides only a tiny fraction of the DM density due to dilution from entropy injection. This fraction of the vector DM suggests that only the extragalactic contribution is relevant in the KM3NeT event because DM lifetime is shorter than the age of the Universe.

Dark matter decays into invisible particles can leave an imprint in large-scale structure surveys due to a characteristic redshift-dependent suppression of the power spectrum. We present a model with two quasi-degenerate singlet fermions, $χ_1$ and $χ_2$, in which the heavier state decays as $χ_2 \to \bar χ_1 νν$ on cosmological time-scales, and that also accommodates non-zero neutrino masses. Remarkably, for parameters that yield the correct dark matter abundance via freeze-in and reproduce the observed neutrino masses, dark matter decay can produce detectable signals in forthcoming large-scale structure surveys, a diffuse anti-neutrino flux accessible to JUNO, and a gamma-ray line within the energy range probed by COSI. Both the cosmological lifetime of $χ_2$ as well as the small (radiatively induced) mass splitting among $χ_{1,2}$ are a natural consequence of the mechanism of neutrino mass generation within this model. This highlights the potential role of large-scale structure surveys in probing some classes of neutrino mass models.

We explore the possibility that the underlying flavour structure of the Standard Model could be determined by mass chains on a fractal geometry. We consider, as an example, the theory space on a Sierpinski-like geometry. The fermion mass chains on a Sierpinski-like geometry with three decorations (iterations) lead to three zero modes, which can be identified with the three generations of the Standard Model. This framework also reproduces the measured charged and neutral lepton masses and mixing angles with very few parameters. We also briefly discuss the possible extension to the quark sector.

In April 2013, the TeV blazar Markarian~421 underwent one of its most powerful emission outbursts to date. An extensive multi-instrument campaign featuring MAGIC, VERITAS, and \textit{NuSTAR} provided comprehensive very-high-energy (VHE; $E > 100$\,GeV) and X-ray coverage over nine consecutive days. In this work, we perform a detailed spectral analysis of the X-ray and VHE emissions on sub-hour timescales throughout the flare. We identify several clockwise spectral hysteresis loops in the X-rays, revealing a spectral evolution more complex than a simple harder-when-brighter trend. The VHE spectrum extends beyond 10\,TeV, and its temporal evolution closely mirrors the behavior in the X-rays. We report the first evidence of VHE spectral hysteresis occurring simultaneously with the X-ray loops. To interpret these findings, we apply a time-dependent leptonic model to 240 broadband spectral energy distributions (SEDs) binned on a 15-minute scale, allowing us to self-consistently track the particle distribution's history. Our modeling shows that the majority of the sub-hour flux and spectral variations are driven by changes in the luminosity and slope of the injected electron distribution. The required variations in the electron slope are difficult to reconcile with magnetic reconnection but are consistent with a shock-acceleration scenario where the shock compression ratio evolves by a factor of $\sim2$. The model also points to a relatively stable magnetic field and emitting region size, favoring a scenario where the emission originates from a stationary feature in the jet, such as a recollimation shock. However, this scenario requires a jet Lorentz factor that significantly exceeds values from VLBI measurements to account for the high minimum electron energy implied by the lack of variability in the optical band.

Recent advances in quantum technologies have enabled quantum simulation of gauge theories -- some of the most fundamental frameworks of nature -- in regimes far from equilibrium, where classical computation is severely limited. These simulators, primarily based on neutral atoms, trapped ions, and superconducting circuits, hold the potential to address long-standing questions in nuclear, high-energy, and condensed-matter physics, and may ultimately allow first-principles studies of matter evolution in settings ranging from the early universe to high-energy collisions. Research in this rapidly growing field is also driving the convergence of concepts across disciplines and uncovering new phenomena. In this Review, we highlight recent experimental and theoretical developments, focusing on phenomena accessible in current and near-term quantum simulators, including particle production and string breaking, collision dynamics, thermalization, ergodicity breaking, and dynamical quantum phase transitions. We conclude by outlining promising directions for future research and opportunities enabled by available quantum hardware.

In this paper we argue that the information load carried by a black hole affects its classical perturbations. We refer to this phenomenon as the ``swift memory burden effect" and show that it is universal for objects of high efficiency of information storage. The effect is expected to have observable manifestations, for example, in mergers of astrophysical black holes in Einstein gravity. The black holes with different information loads, although degenerate in the ground state, respond very differently to perturbations. The strength of the imprint is controlled by the memory burden parameter which measures the fraction of the black hole's memory space occupied by the information load. This represents a new macroscopic quantum characteristics of a black hole. We develop a calculable theoretical framework and derive some master formulas which we then test on explicit models of black holes as well as on solitons of high capacity of information storage. We show that the effect must be significant for the spectroscopy of both astrophysical and primordial black holes and can be potentially probed in gravitational wave experiments. We also provide a proposal for the test of the memory burden phenomenon in a table-top laboratory setting with cold bosons.

Planetesimal formation likely lasted for millions of years in the Solar nebula, and the cold classicals in the Kuiper belt are suggested to be the direct products of streaming instability. The presence of minor planetary bodies in the outer Solar System and the exo-Kuiper belts provide key constraints to planet formation models. In this work, we connected dust drift and coagulation, planetesimal formation, N-body gravity, pebble accretion, planet migration, planetary core accretion, gap opening, and internal photoevaporation in one modeling framework. We demonstrate that multiple classes of minor planets, or planetesimals, can form during disk dissipation and remain afterwards, including a scattered group, a resonant group and a dynamically cold group. Significant growth by pebble accretion was prevented by both dynamical heating due to the giant planet in the system and rapid dispersal of the disk towards the end of its lifetime. We also conducted a parameter study which showed that this is not a universal case, where the outcome is determined by the competition for dust between planetesimal formation and pebble accretion. Combining this scenario with sequential planet formation, this model provides a promising pathway towards an outer Solar System formation model.

In this paper, we present analytical results for the two-loop QCD corrections to the production of two partons or a photon and a parton in hadronic collisions, mediated by loops of massive quarks. These amplitudes involve Feynman integrals defined on an elliptic curve. We compute them by generalizing our recent results for the production of two photons to include additional crossings of the corresponding master integrals, which we compute in terms of the same basis of independent iterated integrals. We discuss the analytical properties of the amplitudes, highlighting the cancellations of a large number of elliptic differential forms in their finite remainders. Finally, we elaborate on a strategy for their numerical evaluation based on generalized series expansions at singular points of the physical amplitude, through the introduction of suitable sets of variables that allow us to resolve all singularities.

Under the core-accretion model, gas giants form via runaway accretion. This process starts when the mass of the accreted envelope becomes equal to the mass of the core. Here, we model a population of warm sub-Saturns to search for imprints of their formation history in their internal structure. Using the GAS gianT modeL for Interiors (GASTLI), we calculate a grid of interior structure models on which we perform retrievals for our sample of 28 sub-Saturns to derive their envelope mass fractions ($f_{env}$). For each planet, we run three different retrievals assuming low (-2.0 < log(Fe/H) < 0.5), medium ( 0.5 < log(Fe/H) < 1.4), and high (1.4 < log(Fe/H) < 1.7) atmospheric metallicity. The distribution of $f_{env}$ in our sample is then compared to predictions of planet formation models. When compared to the outcomes of a planetesimal accretion model, we find that we require medium to high atmospheric metallicities to reproduce the simulated planet population. Additionally, we find a bimodal distribution of $f_{env}$ in our sample with a gap that is located at different values of $f_{env}$ for different atmospheric metallicities. For the high atmospheric metallicity case, the gap in the $f_{env}$ distribution is located between 0.5 and 0.7, which is consistent with assumptions by the core-accretion model where runaway accretion starts when $M_{env} \approx M_{core}$ ($f_{env} \sim 0.5$). We also find a bimodal distribution of the hydrogen and helium mass fraction ($f_{H/He}$) with a gap at $f_{H/He} = 0.3$. The location of this gap is independent of the assumed atmospheric metallicity. Lastly, we compare the distributions of our sub-Saturns in the Neptunian savanna to a population of sub-Saturns in the Neptune desert and ridge. We find that the observed $f_{env}$ distribution of savanna and ridge sub-Saturns is consistent with the planets coming from the same underlying population.

Supernova (SN) 1987A is a celebrated laboratory in searches for gamma-ray flashes produced by the radiative decay of sub-GeV particles such as axion-like particles (ALPs), sterile neutrinos, and novel gauge bosons. At large couplings, however, particles decay rapidly inside the stellar envelope, which results in a suppression of the signal. Focusing on the prototypical example of ALPs with a photon coupling, we show that core-collapse SNe of Type Ic are much less affected by this attenuation, thanks to the compactness of their progenitors ensuing from the loss of their envelope. While Fermi-LAT may miss the brief gamma-ray flash from a single Type Ic SN, their high rate allows for a statistical approach: by stacking many events, we can obtain constraints that significantly surpass those from SN 1987A at large couplings. Our approach can be extended to any feebly interacting particle featuring a decay channel into photons.

The polarized light of the cosmic microwave background is sensitive to new physics that violates parity symmetry. For example, the interaction of photons with the fields of elusive dark matter and dark energy could cause a uniform rotation of the plane of linear polarization across the sky, an effect known as cosmic birefringence. We extract the cosmological rotation angle, $β$, using Bayesian analysis of parity-violating correlations, $EB$ and $TB$, of polarization data from the Atacama Cosmology Telescope (ACT) Data Release 6. We use prior probabilities for instrumental miscalibration angles derived from the optics model for the ACT telescope and instruments, and marginalize over a residual intensity-to-polarization leakage. We measure $β= 0.215^\circ\pm 0.074^\circ$ (68\% confidence level), which excludes $β=0$ with a statistical significance of $2.9σ$. Although there remain systematics in the ACT data that are not understood and do not allow us to draw strong cosmological conclusions, this result is consistent with previous independent results from the \wmap\ and \planck\ missions. It is suggestive that independent data sets and analyses using different methodologies have yielded the same sign and comparable magnitudes for $β$.

GRB 250702B was the longest gamma-ray burst ever observed, 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-meter 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 solar masses, dusty, and extremely asymmetric system that is consistent with two galaxies undergoing a major merger. The galactocentric offset, host galaxy properties, and jet characteristics do not definitively distinguish between competing progenitor scenarios. We find that the afterglow and host are consistent with a range of progenitors including a collapsar, a merger between a helium star and a stellar mass black hole, the disruption of a star by a stellar mass compact object, and the tidal disruption of a star by an off-nuclear intermediate mass black hole.

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 ultra-long gamma-ray bursts (GRBs). However, unlike any known GRB, a soft X-ray precursor was discovered by the Einstein Probe up to 24 hours 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 to 65 days (observer frame) after the initial high-energy trigger. The X-ray emission decays steeply as $\sim t^{-1.9}$, and shows short timescale X-ray variability ($ΔT/T < 0.03$) in both Swift and NuSTAR, consistent with flares superposed on an external shock continuum. Serendipitous detections by the Swift Burst Alert Telescope (BAT) out to $\sim$0.3 days and continued NuSTAR variability to $\sim$2 days imply sustained central engine activity; including the precursor, the required engine duration is $\gtrsim 3$ days. Afterglow modeling favors the combination of forward and reverse shock emission in a wind-like ($k \approx 2$) environment. These properties, especially the long-lived engine and soft X-ray precursor, are difficult to reconcile with a collapsar origin, and GRB 250702B does not fit neatly with canonical ultra-long 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. Decisive discrimination between progenitors will require sensitive late-time X-ray observations.

Nonlinear effects in chemical reactions, coupled with amplifying catalysis, can lead to remarkable phenomena like spontaneous symmetry breaking, central to the origin of biological homochirality. Soai's asymmetric autocatalysis is a prototypical reaction for this, where the enantiomeric excess of the product alcohol is amplified during alkylation of pyridyl and pyrimidyl carbaldehydes by diisopropylzinc. However, the complex equilibria and elusive intermediates make the mechanism difficult to clarify. Here we unravel the intricate dynamics of this reaction by in situ high-resolution mass spectrometry, kinetic analysis, and reaction profile simulations. We identify for both the pyrimidyl and the pyridyl systems transient hemiacetalate isopropyl zinc complexes, formed by the addition of the alcoholate product to the aldehyde, as key catalytic intermediates. These diastereomeric complexes enable dual stereocontrol, explaining the observed enantioselectivity. Our analysis confirms the structures of all intermediates and validates the autocatalytic cycle, offering insights into how substituent and structural variations influence reaction performance. This understanding guides the design of new, efficient asymmetric autocatalytic systems.

We present the first gamma-ray burst (GRB) host galaxy with a measured absorption line and electron temperature (T<inline-formula><tex-math>$_e$</tex-math></inline-formula>) based metallicity, using the temperature sensitive [O III]<inline-formula><tex-math>$\lambda$</tex-math></inline-formula>4363 auroral line detected in the JWST/NIRSpec spectrum of the host of GRB 050505 at redshift <inline-formula><tex-math>$z=4.28$</tex-math></inline-formula>. We find that the metallicity of the cold interstellar gas, derived from the absorption lines in the GRB afterglow, of 12 + log(O/H) <inline-formula><tex-math>$\sim 7.7$</tex-math></inline-formula> is in reasonable agreement with the temperature-based emission line metallicity in the warm gas of the GRB host galaxy, which has values of 12 + log(O/H) = 7.80<inline-formula><tex-math>$\pm$</tex-math></inline-formula>0.19 and 7.96<inline-formula><tex-math>$\pm$</tex-math></inline-formula>0.21 for two common indicators. When using strong emission line diagnostics appropriate for high-z galaxies and sensitive to ionization parameter, we find good agreement between the strong emission line metallicity and the other two methods. Our results imply that, for the host of GRB050505, mixing between the warm and the cold interstellar medium along the line of sight to the GRB is efficient, and that GRB afterglow absorption lines can be a reliable tracer of the metallicity of the galaxy. If confirmed with a large sample, this suggest that metallicities determined via GRB afterglow spectroscopy can be used to trace cosmic chemical evolution to the earliest cosmic epochs and in galaxies far too faint for emission line spectroscopy, even for JWST.

The large $N$ analysis of QCD states that the potential for the $η'$ meson develops cusps at $η' = π/ N_f$, $3 π/N_f$, $\cdots$, with $N_f$ the number of flavors. Furthermore, the recent discussion of generalized anomalies tells us that even for finite $N$ there should be cusps if $N$ and $N_f$ are not coprime, as one can show that the domain wall configuration of $η'$ should support a Chern-Simons theory on it, i.e., domains are not smoothly connected. On the other hand, there is a supporting argument for instanton-like, smooth potentials of $η'$ from the analyses of softly-broken supersymmetric QCD for $N_f= N-1$, $N$, and $N+1$. We argue that the analysis of the $N_f = N$ case should be subject to the above anomaly argument, and thus there should be a cusp; while the $N_f = N \pm 1$ cases are consistent, as $N_f$ and $N$ are coprime. We discuss how this cuspy/smooth transition can be understood. For $N_f< N$, we find that the number of branches of the $η'$ potential is $\operatorname{gcd}(N,N_f)$, which is the minimum number allowed by the anomaly. We also discuss the condition for s-confinement in QCD-like theories, and find that in general the anomaly matching of the $θ$ periodicity indicates that s-confinement can only be possible when $N_f$ and $N$ are coprime. The s-confinement in supersymmetric QCD at $N_f = N+1$ is a famous example, and the argument generalizes for any number of fermions in the adjoint representation.

Shocks are promising sites of particle acceleration in extragalactic jets. In electron-ion shocks, electrons can be heated up to large Lorentz factors, making them an attractive scenario to explain the high minimum electron Lorentz factors regularly needed to describe the emission of BL Lac objects. Still, the thermal electron component is commonly neglected when modelling the observations, although it holds key informations on the shock properties. We model the broadband emission of the HSP blazar Mrk421 employing particle distributions that include a thermal relativistic Maxwellian component at low energies followed by a nonthermal power-law, as motivated by PIC simulations. The observations in the optical/UV and MeV-GeV bands efficiently restrict the nonthermal emission from the Maxwellian electrons, which we use to derive constraints on the basic properties, such as the fraction $ε_e$ of the total shock energy stored in the nonthermal electrons. The best-fit model yields a nonthermal electron power-law with an index of ~2.4, close to predictions from shock acceleration. Successful fits are obtained when the ratio between the Lorentz factor at which the nonthermal distribution begins ($γ_{\rm nth}$) and the dimensionless electron temperature ($θ$) satisfies $γ_{\rm nth}/θ\lesssim 8$. Since $γ_{\rm nth}/θ$ controls $ε_e$, the latter limit implies that at least $ε_e \approx 10\%$ of the shock energy is transferred to the nonthermal electrons. These results are almost insensitive to the shock velocity $γ_{\rm sh}$, but radio observations indicate $γ_{\rm sh} \gtrsim 5$ since for lower shock velocities the radio fluxes are overproduced by the Maxwellian electrons. If shocks drive the particle energisation, our findings indicate that they operate in the mildly to fully relativistic regime with efficient electron acceleration.

Blazars are promising high-energy neutrino source candidates. Yet, leptohadronic models face challenges in describing neutrino emission within a viable energy budget, and their predictive power is limited by the commonly used single-zone approximation and the reliance on phenomenological parameters. In this work, we present a new leptohadronic model where a sub-Eddington jet evolves from magnetically- to kinetically dominated. A small fraction of the electrons and protons picked up by the jet are continuously accelerated to a power-law spectrum, estimated based on the local magnetic field strength, turbulence, and ambient density, for which we assume power-law profiles. The model parameters are thus directly tied to the jet physics and are comparable in number to typical single-zone models. We then numerically calculate the emission along the jet. Applying the model to the IceCube candidate TXS 0506+056, we find that protons are accelerated to EeV energies in the inner jet, producing a neutrino flux up to order 100 PeV that is consistent with the public 10 year IceCube point-source data. Proton emission at 0.1 pc describes the X-ray and gamma-ray data, while electron emission at the parsec scale describes the optical data. Protons carry a power of about 1% of the Eddington luminosity, showing that the model is energetically viable. The particle spectra follow $E^{-1.8}$, with diffusion scaling as $E^{0.3}$, ruling out Bohm-like diffusion. Additional particle injection near the broad line region can reproduce the 2017 flare associated to a high-energy neutrino. We also apply the model to blazar PKS 0605-085, which may be associated with a recent neutrino detected by KM3NeT above 100 PeV. The results suggest that blazars are efficient neutrino emitters at ultra-high energies, making them prime candidates for future experiments targeting this challenging energy range.

We present a neural-network framework designed to reconstruct the properties of cosmic-ray nuclei traversing the scintillating-fiber tracking calorimeter of the RadMap Telescope. Employing the Geant4 simulation toolkit and a simplified model of the detector to generate training and test data, we achieve the spectroscopic capabilities required for an accurate determination of the biologically relevant dose that astronauts receive in space. We can reconstruct a particle's trajectory with an angular resolution of better than $1.4^\circ$ and achieve a charge separation of better than $95\%$ for nuclei with $Z\leq8$; specifically, we reach an accuracy of $99.8\%$ for hydrogen. The energy resolution is $<20\%$ for energies below 1 GeV/n and elements up to iron. We also discuss the limitations of our detector, the reconstruction framework, and this feasibility study, as well as possible improvements.

We present simulations of the supernova-driven turbulent interstellar medium (ISM) in a simulation domain of volume (256 pc)³ within which we resolve the formation of protostellar accretion disks and their stellar cores to spatial scales of ~10^-4 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 disks, their location within the larger-scale structure and the streamers connecting these. We find that disks of sizes 10 - 100 au form early in the simulations without magnetic fields, while there are no disks larger than 10 au with ideal MHD. Ambipolar diffusion causes large disks 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 disk. Magnetic fields strengths grow from 0.1 - 1 mG in the protostellar core to more than 10 G in the first Larson core in all simulations with ideal MHD. The rotationally supported disks which form can have rotation speeds >1 km s^-1 even out to further than 100 au from the centre, become gravitationally unstable and form complex spiral substructures with Toomre Q < 1. We conclude that the impact of magnetic fields and non-ideal MHD on the formation of protostellar disks is substantial in realistic formation scenarios from the turbulent ISM.

The innermost parts of the Milky Way (MW) are very difficult to observe due to the high extinction along the line of sight, especially close to the disc mid-plane. However, this region contains the most massive complex stellar component of the MW, the bulge, primarily composed of disc stars whose structure is (re-)shaped by the evolution of the bar. In this work, we extend the application of the orbit superposition method to explore the present-day 3D structure, orbital composition, chemical abundance trends and kinematics of the MW bulge. Thanks to our approach, we are able to transfer astrometry from Gaia and stellar parameters from APOGEE DR 17 to map the inner MW without obscuration by the survey footprint and selection function. We demonstrate that the MW bulge is made of two main populations originating from a metal-poor, high-α thick disc and a metal-rich, low-α thin disc, with a mass ratio of 4:3, seen as two major components in the metallicity distribution function (MDF). Finer MDF structures hint at multiple sub-populations associated with different orbital families of the bulge, which, however, have broad MDFs themselves. Decomposition using 2D Gaussian Mixture Models in the [Fe/H]-[Mg/Fe] plane identifies five components, including a population with ex-situ origin. Two dominant ones correspond to the thin and thick discs, and two in between trace the transition between them. We show that there is no universal metallicity gradient value that can characterise the MW bulge. The radial gradients closely trace the X-shaped bulge density structure, while the vertical gradient variations follow the boxy component. The MW bulge, while on average having subsolar metallicity, is more metal-rich compared to the surrounding disc populations, in agreement with extragalactic observations and state-of-the-art simulations, reinforcing its secular origin.

We describe an attempt of string theoretic derivation of the Gibbons-Hawking entropy. Despite not admitting a de Sitter vacuum, the string theory, by the power of open-close correspondence, captures the Gibbons-Hawking entropy as the entropy of Chan-Paton species on a de Sitter-like state obtained via D-branes. Moreover, this derivation sheds a new light at the origin of the area-form, since the equality takes place for a critical 't Hooft coupling for which the species entropy of open strings saturates the area-law unitarity bound.

In this exploratory work we analyze the possible existence of a strangeness <inline-formula><mml:math><mml:mrow><mml:mi>S</mml:mi><mml:mo>=</mml:mo><mml:mo>-</mml:mo><mml:mn>3</mml:mn></mml:mrow></mml:math></inline-formula>, isospin <inline-formula><mml:math><mml:mrow><mml:mi>I</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:math></inline-formula> pentaquark state <inline-formula><mml:math><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mi>sss</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> generated dynamically from the <inline-formula><mml:math><mml:mrow><mml:mover><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mo>¯</mml:mo></mml:mrow></mml:mover><mml:mi>Ξ</mml:mi></mml:mrow></mml:math></inline-formula> interaction. We employ a unitarized scheme in coupled channels based on the chiral Lagrangian expanded up to next-to-leading order (NLO), and show that the inclusion of the NLO terms can be crucial to provide the necessary attraction that favors the existence of such triply strange pentaquark. The <inline-formula><mml:math><mml:mrow><mml:mover><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mo>¯</mml:mo></mml:mrow></mml:mover><mml:mi>Ξ</mml:mi></mml:mrow></mml:math></inline-formula> femtoscopic correlation functions are calculated as example of a possible experimental measurement in which a direct signal of the <inline-formula><mml:math><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mi>sss</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> state could be observed.

Red supergiants (RSGs), which are progenitors of hydrogen-rich Type II supernovae (SNe), have been known to pulsate from both 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 solar-mass RSG and self-consistently follow the hydrodynamical evolution. We find the growth of large amplitude radial pulsations in the envelope. After a transient phase where 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 non-coherent expansion and contraction in different parts of the envelope, which greatly affect the SN progenitor properties, including its location in the Hertzsprung-Russell diagram. We simulate SN explosions of this model at different pulsations 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.

Context. The distribution of chemical elements in star-forming regions can store information on the chemical enrichment history of galaxies and particularly of recent events. Negative metallicity gradients are expected in galaxies forming inside-out. Azimuthal-averaged profiles are usually fit to the projected chemical distributions to quantify them. However, observations show that the metallicity profiles can be broken. Aims. We aim to study the diversity of metallicity profiles that can arise in the current cosmological context and compare them with available observations. Additionally, we seek to identify the physical processes responsible for breaks in metallicity profiles by using two galaxies as case studies. Methods. We analyzed central galaxies from the cosmological simulations of CIELO project, with stellar masses within the range of 10^8.5 to 10^10.5 M_⊙ at z = 0. A new algorithm, DB-A, was developed to fit multiple power laws to the metallicity profiles, enabling a flexible assessment of metallicity gradients in various galactic regions. The simulations include detailed modeling of gas components, metal-dependent cooling, star formation, and supernova feedback. Results. At z = 0, we find a diversity of shapes, with inner and outer drops and rises, and there are a few galaxies with double breaks. Inner, outer, and middle gradients are in agreement with observations. We also find that using a single linear regression to fit gradients usually traces the middle gradient well. A detailed temporal analysis of the main galaxies of a Local Group analog revealed the occurrence of inner and outer breaks at all cosmic times, with the latter being the most common feature during the evolution of our case studies. Significant variability in the metallicity gradients was found at high redshift, transitioning to more gradual evolution at lower redshifts. Most of the inner breaks have enhanced oxygen abundances in the center, which are linked to gas accretion followed by efficient star formation. Inner breaks with diluted oxygen abundances are less common and are found in galaxies with disrupted gas distributions which are affected by feedback-driven ejection of enriched gas. Outer breaks with high abundances are linked to processes such as the re-accretion of enriched material, extended star formation, and enhanced gas mixing from the circumgalactic medium. Outer breaks with diluted metallicities in the outskirts are found mainly at high redshift and are associated with the accretion of metal-poor gas from cold flows. We also highlight and illustrate the complex interplay of these processes which act often together.

Recent hydrodynamical simulations of isolated barred disc galaxies have suggested a structural change in the distribution of the interstellar medium (ISM) around a stellar mass M_* of 10¹⁰ M_⊙. In the higher-mass regime (M_∗ ≥ 10¹⁰ M_⊙), we observe the formation of a central gas and stellar disc with a typical size of a few hundred parsecs connected through lanes to the ends of the stellar bar. In the lower-mass regime (M_∗ < 10¹⁰ M_⊙), such an inner disc is absent and the gas component exhibits a more chaotic distribution. Observations of nearby star-forming galaxies support the existence of such a change. These inner gas discs may represent an important intermediate scale connecting the large kiloparsec-scale structures with the nuclear (sub-parsec) region, transporting gas inwards to fuel the central supermassive black hole (SMBH). For this work we used an extended set of high-resolution hydrodynamical simulations of isolated disc galaxies with initial properties (i.e. stellar mass, gas fraction, stellar disc scale length, and the bulge mass fraction) with properties covering the range of galaxies in the PHANGS sample to investigate this change of regime. We studied the physical properties of the star-forming ISM in both stellar mass regimes and extracted a few physical tracers: the inner Lindblad resonance (ILR), the probability distribution function (PDF), the virial parameter, and the Mach number. In line with observations, we confirm a structure transition in the simulations that occurs between a stellar mass of 10^9.5 and 10¹⁰ M_⊙. We show that the physical origin of this change of regime is driven by stellar feedback and its contribution relative to the underlying gravitational potential. With their shallower potential and typically higher gas mass fraction, lower-mass disc PHANGS galaxies combine two ingredients that significantly delay or even prevent the formation of a central gas (and stellar) disc. These results shed some light on the observed properties of star-forming barred galaxies and have implications for the star formation regimes, the growth of central structures, and the overall secular evolution of disc galaxies.

We investigate the high-ionization, narrow [Ne V] λ3427 line emission in a sample of over 340 ultrahard X-ray (14–195 keV) selected active galactic nuclei (AGN) drawn from the BAT AGN Spectroscopic Survey project. The analysis includes measurements in individual and stacked spectra and considers several key AGN properties such as X-ray luminosity, supermassive black hole (SMBH) mass, Eddington ratios, and line-of-sight column density. The [Ne V] λ3427 line is robustly detected in ≈43% (146/341) of the AGN in our sample, with no significant trends between the detection rate and key AGN/SMBH properties. In particular, the detection rate remains high even at the highest levels of obscuration (>70% for <inline-formula> <mml:math><mml:mi>log</mml:mi><mml:mfenced><mml:mrow><mml:msub><mml:mi>N</mml:mi><mml:mi>H</mml:mi></mml:msub><mml:mo>/</mml:mo><mml:msup><mml:mi>cm</mml:mi><mml:mrow><mml:mo>‑</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:mfenced><mml:mo>)</mml:mo><mml:mo>≳</mml:mo><mml:mn>23</mml:mn></mml:math> </inline-formula>). On the other hand, even some of our highest signal-to-noise spectra (S/N > 50) lack a robust [Ne v] detection. The typical (median) scaling ratios between [Ne v] line emission and (ultra)hard X-ray emission in our sample are <inline-formula> <mml:math><mml:mi>log</mml:mi><mml:msub><mml:mrow><mml:mi>L</mml:mi></mml:mrow><mml:mrow><mml:mo>[</mml:mo><mml:mi>Ne</mml:mi><mml:mspace></mml:mspace><mml:mi>V</mml:mi><mml:mo>]</mml:mo></mml:mrow></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mrow><mml:mi>L</mml:mi></mml:mrow><mml:mrow><mml:mn>14</mml:mn><mml:mo>‑</mml:mo><mml:mn>150</mml:mn><mml:mspace></mml:mspace><mml:mi>keV</mml:mi></mml:mrow></mml:msub><mml:mo>≃</mml:mo><mml:mo>‑</mml:mo><mml:mn>3.75</mml:mn></mml:math> </inline-formula> and <inline-formula> <mml:math><mml:mi>log</mml:mi><mml:msub><mml:mrow><mml:mi>L</mml:mi></mml:mrow><mml:mrow><mml:mo>[</mml:mo><mml:mi>Ne</mml:mi><mml:mspace></mml:mspace><mml:mi>V</mml:mi><mml:mo>]</mml:mo></mml:mrow></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mrow><mml:mi>L</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn><mml:mo>‑</mml:mo><mml:mn>10</mml:mn><mml:mspace></mml:mspace><mml:mi>keV</mml:mi></mml:mrow></mml:msub><mml:mo>≃</mml:mo><mml:mo>‑</mml:mo><mml:mn>3.36</mml:mn></mml:math> </inline-formula>. The scatter on these scaling ratios, ≲0.5 dex, is comparable to, and indeed smaller than, what is found for other commonly used tracers of AGN radiative outputs (e.g., [O III] λ5007). Otherwise, we find no significant relations between the (relative) strength of [Ne v] and the basic AGN/SMBH properties under study, in contrast with simple expectations from models of SMBH accretion flows. Our results reaffirm the usability of [Ne v] as an AGN tracer even in highly obscured systems, including dual AGN and high-redshift sources.

Aims. We investigated the gas reservoirs, star formation properties, and environment of the ultra-diffuse galaxy GAMA 526784 to understand its formation history, the efficiency of molecular gas conversion into stars, and the possible role of an interacting companion in shaping its current morphology. Methods. We analysed low- and high-resolution CO observations to place constraints on the molecular gas content of the galaxy, compared them with HI data, and examined the star formation efficiency of GAMA 526784. The potential influence of a newly identified nearby dwarf galaxy was assessed using photometric and spatial information. Results. GAMA 526784 exhibits a regular HI reservoir (M_HI/M_⋆ = 2.88), but we are only able to place upper limits on its molecular gas mass (M_H2(5σ)/M_⋆ < 0.23). The galaxy's HI reservoir and CO non-detection can be explained by several mechanisms: (1) the predominance of CO-dark H₂, which remains invisible to CO observations but contributes to star formation; (2) a time delay in HI-to-H₂ conversion following a recent interaction; or (3) elevated turbulence inhibiting gas collapse. An identified companion, optically found at a projected distance of ∼48 kpc, shows similar colours and lies in the direction of the young star clusters in GAMA 526784, indicating a possible association. We hypothesise that this companion may have triggered the formation of the star clusters in GAMA 526784 through a high-velocity encounter. Conclusions. Our findings suggest that GAMA 526784 may have undergone a dwarf–dwarf interaction that significantly influenced its gas reservoirs and star formation activity. The presence of a nearby companion galaxy is consistent with predictions of a high-speed encounter, potentially offering a rare observational example of such an interaction in progress. We hypothesise that this encounter may have played a key role in shaping the system's recent evolution. Future observations, particularly targeting molecular gas tracers beyond CO and resolved HI observations, will be crucial in determining the true extent of GAMA 526784's cold gas reservoir and the nature of its recent star formation activity.

Aims. Pulsating variable stars are invaluable tracers for reconstructing the star formation history and chemical evolution of their host galaxies. In this work, we explore the variable star population of Leo II, a distant dwarf spheroidal satellite of the Milky Way. Methods. We analyse an extensive dataset of ground-based BVRI time-series photometry spanning over 35 years. By examining the properties of RR Lyrae stars, we constrain the early chemical enrichment and spatial variation within Leo II. Additionally, we investigate the anomalous Cepheids in order to connect their characteristics with the galaxy's prolonged star formation history, as revealed by deep HST/WFC3 colour–magnitude diagrams. Results. We identified and characterised 175 variable stars, with all but one associated with Leo II. Our work includes the discovery of 25 new RR Lyrae stars and two new anomalous Cepheids. Moreover, we reclassified V88 as a BL Her variable star. By employing multiple independent methods, including metallicity-luminosity relations for RR Lyrae stars and period–luminosity and period–Wesenheit relations for both RR Lyrae and anomalous Cepheids, we derived a true distance modulus of (m ‑ M)₀ = 21.60 ± 0.03 mag, corresponding to 209 ± 4 kpc. Furthermore, we discuss potential formation scenarios for anomalous Cepheids and suggest that, despite the extended star formation history, they are all compatible having originated from old binary stars, with no contribution from young, evolved single stars.

The stellar disc is the dominant luminous component of the Milky Way (MW). Although our understanding of its structure is rapidly expanding due to advances in large-scale surveys of stellar populations across the Galaxy, our picture of the disc remains substantially obscured by selection functions and an incomplete spatial coverage of observational data. In this work, we present the comprehensive chrono-chemo-kinematic structure of the MW disc, recovered using a novel orbit superposition approach combined with data from APOGEE DR 17. We detected periodic azimuthal metallicity variations within 6–8 kpc with an amplitude of 0.05–0.1 dex peaking along the bar major axis. The radial metallicity profile of the MW also varies with azimuth, displaying a pattern typical among other disc galaxies, namely: a decline outside the solar radius and an almost flat profile in the inner region, attributed to the presence of old, metal-poor high-α populations, comprising ≈40% of the total stellar mass. The geometrically defined thick disc and the high-α populations have comparable masses, but with differences in their stellar population content, which we quantified using the reconstructed 3D MW structure. The well-known [α/Fe]-bimodality in the MW disc, once it has been weighted by the stellar mass, is less pronounced at a given metallicity for the whole galaxy but distinctly visible in a narrow range of galactic radii (5–9 kpc), explaining its relative lack of prominence in external galaxies and galaxy formation simulations. Analysing a more evident double age–abundance sequence, we constructed a scenario for the MW disc formation, advocating for an inner and outer disc dichotomy genetically linked to the MW's evolutionary stages. In this picture, the extended solar vicinity is a transition zone that shares the chemical properties of both the inner (old age-metallicity sequence) and outer discs (young age-metallicity sequence).

AT 2019aalc is a peculiar sequence of highly variable emission events observed towards the nucleus of the broad-line active galactic nucleus (AGN) SDSS J152416.66+045119.0. The system exhibited two distinct UV-optical flares (the first detected in 2019, the second one in 2023). Spectra obtained following the detection of the second flare revealed prominent Bowen fluorescence (BF) and high-ionization coronal emission lines, which were much weaker, if at all detectable, in a spectrum taken following the first flare. We present and analyze a large set of multi-wavelength, multi-epoch data for this source, with particular emphasis on optical spectroscopic monitoring conducted with the Las Cumbres Observatory network. During the relatively slow dimming that followed the second optical flare, the UV-optical light curve shows a sequence of minor rebrightening events, while the BF and the coronal lines vary (roughly) in tandem with these "bumps" in the broadband light curve. Most of the observed behavior of AT 2019aalc links it to the growing class of BF flares while setting it apart from canonical tidal disruption events. However, AT 2019aalc has some outstanding peculiarities, including two short flares seen in its soft X-ray light-curve during the dimming phase of the second optical flare, and which do not seem to be linked to the emission line variations. We discuss the optical and X-ray properties of the source and possible scenarios of the origin of the flare, in particular radiation pressure instabilities in the (preexisting) AGN accretion disk.

Context. Dark matter (DM) particles can interact with particles characterised by the standard model. Although there are a number of constraints derived from direct and indirect detection experiments, the dynamical evolution of astrophysical objects could offer a promising probe for such interactions. Obtaining astrophysical predictions is challenging and primarily limited by our ability to simulate scattering between DM and baryonic particles within N-body and hydrodynamics simulations. Aims. We have developed the first scheme allowing for the simulation of these interacting dark matter (IDM) models, accurately accounting for their angular and velocity dependence, as well as the mass ratio between the DM and baryonic scattering partners. Methods. To describe DM-baryon interactions, we used an N-body code together with its implementation of smoothed-particle hydrodynamics (SPH) and meshless finite mass. The interaction itself was realised in a pairwise fashion by creating a virtual scattering partner from the baryonic particle and allowing it to interact with a DM particle using a scattering routine initially developed for self-interacting dark matter (SIDM). After the interaction, the virtual particle is rejoined with the baryonic particle, fulfilling the requirements of energy and momentum conservation. Results. Through several test problems, we demonstrated that we are able to reproduce the analytic solutions with our IDM scheme. This includes a test for scattering with a physical mass ratio of 1:1000, which is beyond the limits of current SIDM simulations. We comment on various numerical aspects and challenges, and we describe the limitations of our numerical scheme. Furthermore, we study the impact of IDM on halo formation with a collapsing over-density. Conclusions. We find that it is possible to accurately model IDM within N-body and hydrodynamics simulations commonly used in astrophysics. Finally, our scheme allows for novel predictions to be made and new constraints on DM-baryon scattering to be set.

Neutrinos experience collective flavor conversion in extreme astrophysical environments such as core-collapse supernovae (CCSNe). One manifestation of collective conversion is slow flavor conversion (SFC), which has recently attracted renewed interest owing to its ubiquity across different regions of the supernova environment. In this study, we systematically examine the evolution of kinematic decoherence in a dense neutrino gas undergoing SFC, considering lepton number asymmetries as large as 30%. Our findings show that the neutrino gas asymptotically evolves toward a generic state of coarse-grained flavor equilibration which is constrained by approximate lepton number conservation. The equilibration occurs within a few factors of the inverse vacuum oscillation frequency, <inline-formula><mml:math><mml:msup><mml:mi>ω</mml:mi><mml:mrow><mml:mo>-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math></inline-formula>, which corresponds to (anti)neutrinos reaching near flavor equipartition after a few kilometers for typical supernova neutrino energies. Notably, the quasisteady state of the neutrino number densities can be quantitatively described by the neutrino-antineutrino number density ratio <inline-formula><mml:math><mml:msub><mml:mi>n</mml:mi><mml:msub><mml:mover><mml:mi>ν</mml:mi><mml:mo>¯</mml:mo></mml:mover><mml:mi>e</mml:mi></mml:msub></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mi>n</mml:mi><mml:msub><mml:mi>ν</mml:mi><mml:mi>e</mml:mi></mml:msub></mml:msub></mml:math></inline-formula> alone. Such a simple estimation opens new opportunities for incorporating SFC into CCSN simulations, particularly in regions where SFC develops on scales much shorter than those of collisions.

Galaxy groups and clusters are among the best probes of structure formation and growth in a cosmological context. Most of their baryonic component is dominated by hot plasma, known as the intracluster medium (ICM) in clusters or the intragroup medium (IGrM) in groups. Their thermodynamical properties serve as indicators of the halo's dynamical state and can be used to determine halo mass in the self-similar scenario. However, baryonic processes, such as AGN feedback and gas cooling, may affect the global properties of the ICM, especially in the group regime. These effects might lead to deviations from self-similar predictions in the scaling relations of galaxy groups, while they remain in place for massive galaxy clusters. Additionally, the low-mass end of the scaling relations, ranging from 10¹³ to 10¹⁴ M_⊙, remains unclear and poorly populated, as current X-ray surveys detect only the brightest groups. Here, we present the mass-temperature relation across the entire mass range, from massive clusters to low-mass groups (10¹³ M_⊙), as observed by eROSITA. Using spectral stacking from the first eROSITA All-Sky Survey data for optically selected galaxy groups, we find that, in the lower mass range, galaxy groups follow the power-law relation known for galaxy clusters. We provide the best-fit mass–temperature relation, validated over two decades in halo mass, as follows: log₁₀(M₅₀₀/M_⊙) = (1.65 ± 0.11)ṡlog₁₀(T_X/1 keV)+(13.38 ± 0.05). We further validate these results by conducting the same stacking procedure on mock eRASS:4 data using the MAGNETICUM hydrodynamical simulation. This indicates that AGN feedback is more likely to affect the distribution of baryons in the intragroup medium rather than the overall halo gas temperature. No significant changes in the slope of the mass-temperature relation suggest that temperature can serve as a reliable mass proxy across the entire mass range. This supports the use of temperature-derived masses, particularly in cosmological studies, significantly broadening the mass range and enabling applications such as improving cluster mass function studies and cosmological parameter estimates.

The characterization of nearby rocky exoplanets will become feasible with the next generation of telescopes, such as the Extremely Large Telescope (ELT) and the mission concept Habitable Worlds Observatory (HWO). Using an improved model setup, we aim to refine the estimates of reflected and polarized light contrast for a selected sample of rocky exoplanets in the habitable zones of nearby stars. We perform advanced 3D radiative transfer simulations for Earth-like planets orbiting G-type and M-type stars. Our simulations incorporate realistic, wavelength-dependent surface albedo maps and a detailed cloud treatment, including 3D cloud structures and inhomogeneities, to better capture their radiative response. These improvements are based on Earth observations. We present models of increasing complexity, ranging from simple homogeneous representations to a detailed Earth-as-an-exoplanet model. Our results show that averaging homogeneous models fails to capture Earth's full complexity, especially in polarization. Moreover, simplistic cloud models distort the representation of absorption lines at high spectral resolutions, particularly in water bands, potentially biasing atmospheric chemical abundance estimates. Additionally, we provide updated contrast estimates for observing rocky exoplanets around nearby stars with upcoming instruments such as ANDES and PCS at the ELT. Compared to previous studies, our results indicate that reflected light contrast estimates are overestimated by a factor of two when simplified cloud and surface models are used. Instead, measuring the fractional polarization in the continuum and in high-contrast, high-resolution spectra may be more effective for characterizing nearby Earth-like exoplanets. These refined estimates are essential for guiding the design of future ELT instruments and the HWO mission concept.

We study the generalized charm susceptibilities in <inline-formula><mml:math><mml:mrow><mml:mn>2</mml:mn><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:math></inline-formula> flavor QCD on the lattice at several lattice spacings. We show that, below the chiral crossover, these susceptibilities are well described by the hadron resonance gas (HRG) model if charmed hadrons not listed in tables of the Particle Data Group are included. However, the HRG description abruptly breaks down just above the chiral crossover. To understand this, we use a model for the charm pressure in which it is expressed as the sum of partial pressures from charmed baryons, charmed mesons, and charm quarks. We present continuum estimates of these partial pressures and find that, while the partial pressures of charmed mesons and baryons drop below their respective HRG predictions, the charm quark pressure becomes nonzero above the chiral crossover.

We investigate the spectral behavior of scalar fluctuations generated by gravity during inflation and the subsequent reheating phase. We consider a nonperturbative Bogoliubov treatment within the context of pure gravitational reheating. We compute both long- and short-wavelength spectra, first for a massless scalar field, revealing that the spectral index in part of the infrared (IR) regime varies between <inline-formula><mml:math><mml:mo>-</mml:mo><mml:mn>6</mml:mn></mml:math></inline-formula> and <inline-formula><mml:math><mml:mo>-</mml:mo><mml:mn>3</mml:mn></mml:math></inline-formula>, depending on the postinflationary equation of state (EoS), <inline-formula><mml:math><mml:mn>0</mml:mn><mml:mo>≤</mml:mo><mml:msub><mml:mi>w</mml:mi><mml:mi>ϕ</mml:mi></mml:msub><mml:mo>≤</mml:mo><mml:mn>1</mml:mn></mml:math></inline-formula>. Furthermore, we study the mass-breaking effect of the IR spectrum by including the finite mass, <inline-formula><mml:math><mml:msub><mml:mi>m</mml:mi><mml:mi>χ</mml:mi></mml:msub></mml:math></inline-formula>, of the daughter scalar field. We show that for <inline-formula><mml:math><mml:msub><mml:mi>m</mml:mi><mml:mi>χ</mml:mi></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mi>H</mml:mi><mml:mi>e</mml:mi></mml:msub><mml:mo>≳</mml:mo><mml:mn>3</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn></mml:math></inline-formula>, where <inline-formula><mml:math><mml:msub><mml:mi>H</mml:mi><mml:mi>e</mml:mi></mml:msub></mml:math></inline-formula> is the Hubble parameter during inflation, the IR spectrum of scalar fluctuations experiences exponential mass suppression, while for smaller masses, <inline-formula><mml:math><mml:msub><mml:mi>m</mml:mi><mml:mi>χ</mml:mi></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mi>H</mml:mi><mml:mi>e</mml:mi></mml:msub><mml:mo><</mml:mo><mml:mn>3</mml:mn><mml:mo>/</mml:mo><mml:mn>2</mml:mn></mml:math></inline-formula>, the spectrum remains flat in the IR regime regardless of the postinflationary EoS. For any general EoS, we also compute a specific IR scale, <inline-formula><mml:math><mml:msub><mml:mi>k</mml:mi><mml:mi>m</mml:mi></mml:msub></mml:math></inline-formula>, of fluctuations below which the IR spectrum will suffer from this finite mass effect. In the UV regime, oscillations of the inflaton background lead to interference terms that explain the high-frequency oscillations in the spectrum. Interestingly, we find that for any EoS, <inline-formula><mml:math><mml:mn>1</mml:mn><mml:mo>/</mml:mo><mml:mn>9</mml:mn><mml:mo>≲</mml:mo><mml:msub><mml:mi>w</mml:mi><mml:mi>ϕ</mml:mi></mml:msub><mml:mo>≲</mml:mo><mml:mn>1</mml:mn></mml:math></inline-formula>, the spectral behavior turns out to be independent of the EoS, with a spectral index <inline-formula><mml:math><mml:mo>-</mml:mo><mml:mn>6</mml:mn></mml:math></inline-formula>. We have compared this Bogoliubov treatment for the UV regime to perturbative computations with solutions to the Boltzmann equation and found an agreement between the two approaches for any EoS, <inline-formula><mml:math><mml:mn>0</mml:mn><mml:mo>≲</mml:mo><mml:msub><mml:mi>w</mml:mi><mml:mi>ϕ</mml:mi></mml:msub><mml:mo>≲</mml:mo><mml:mn>1</mml:mn></mml:math></inline-formula>. We also explore the relationship between the gravitational reheating temperature and the reheating EoS employing the nonperturbative analytic approach, finding that reheating can occur for <inline-formula><mml:math><mml:msub><mml:mi>w</mml:mi><mml:mi>ϕ</mml:mi></mml:msub><mml:mo>≳</mml:mo><mml:mn>0.6</mml:mn></mml:math></inline-formula>.

The decay of metastable false-vacuum states via bubble nucleation plays a crucial role in many cosmological scenarios. Cold-atom analog experiments will soon provide the first empirical probes of this process, with potentially far-reaching implications for early-universe cosmology and high-energy physics. However, an inevitable difference between these analog systems and the early universe is that the former have a boundary. We show, using a combination of Euclidean calculations and real-time lattice simulations, that these boundaries generically cause rapid bubble nucleation on the edge of the experiment, obscuring the bulk nucleation that is relevant for cosmology. We demonstrate that implementing a high-density trench region at the boundary completely eliminates this problem and recovers the desired cosmological behavior. Our findings are relevant for ongoing efforts to probe vacuum decay in the laboratory, providing a practical solution to a key experimental obstacle.

Line intensity mapping (LIM) is an emerging technique for probing the large scale structure (LSS) in the post-reionisation era. This captures the integrated flux of a particular spectral line emission from multiple sources within a patch of the sky without resolving them. Mapping different galaxy line emissions, such as the HI $21$-cm and CO rotational lines via LIM, can reveal complementary information about the bias with which the line emitters trace the underlying matter distribution and how different astrophysical phenomena affect the clustering pattern of these signals. The stage where the structures in the cosmic web merge to form a single connected structure is known as the percolation transition. Using mock HI $21$-cm and CO($1-0$) LIM signals in the post-reionisation universe, we explore the connectivity of structures through percolation analysis and compare it with that of the underlying galaxy distribution. We probe the relative contributions of voids, filaments, and sheets to the galaxy density and line intensity maps using a morphological measure known as the local dimension. The CO($1-0$) map exhibits an increased filamentary behaviour and larger contribution from sheets than the $21$-cm map. We attempt to explain such an emission of the CO($1-0$) line from biased environments. The upcoming SKA-Mid will produce tomographic intensity maps of the $21$-cm signal at $z \lesssim 3$ in Band-1. CO maps can be produced at these redshifts in phase 2 of SKA-Mid, where the frequency coverage is expected to increase up to $\sim 50$ GHz. We present forecasts for the recovery of the local dimensions of these intensity maps contaminated by instrumental noise, considering SKA-Mid observations.

Atmospheres of transiting exoplanets can be studied spectroscopically using space-based or ground-based observations. Each has its own strengths and weaknesses, so there are benefits to both approaches. This is especially true for challenging targets such as cooler, smaller exoplanets whose atmospheres likely contain many molecular species and cloud decks. We aim to study the atmosphere of the warm Neptune-like exoplanet WASP-107 b (Teq~740 K). Several molecular species have been detected in this exoplanet in recent space-based JWST studies, and we aim to confirm and expand upon these detections using ground-based VLT, evaluating how well our findings agree with previously retrieved atmospheric parameters. We observe two transits of WASP-107 b with VLT/CRIRES+ and create cross-correlation templates of the target atmosphere based on retrieval results from JWST studies. We create different templates to investigate the impact of varying volume mixing ratios of species and inclusion or exclusion of clouds. Considering this target's observational challenges, we create simulated observations prior to evaluating real data to assess expected detection significances. We report detections of two molecular species, CO (~6 S/N) and H2O (~4.5 S/N). This confirms previous space-based detections and demonstrates, for the first time, the capability of VLT/CRIRES+ to detect species in targets cooler than hot Jupiters using transmission spectroscopy. We show our analysis is sensitive to cloud inclusion, but less so to different volume mixing ratios. Interestingly, our detection deviates from its expected location in our Kp-vsys diagrams, and we speculate on possible reasons for this. We demonstrate that the error budget for relatively cooler exoplanets is severely reduced in comparison to hotter exoplanets, and underline need for further work in context of high-resolution spectroscopy.

Precise predictions for Higgs decays are a crucial ingredient of the search for beyond the Standard Model (BSM) physics and the Standard Model Effective Field Theory (SMEFT) is a valuable tool for quantifying deviations from the Standard Model (SM). We present the complete set of predictions for the 2- and 3- body Higgs decays at next-to-leading order (NLO), considering QCD and electroweak corrections and including all contributions from the dimension-6 SMEFT operators and with an arbitrary flavor structure. Including the NLO SMEFT results for Higgs decays greatly increases the sensitivity to BSM physics of the $e^+e^-\rightarrow Zh$ process at FCC-ee, as compared with that obtained using only the total cross section.

The C-MetaLL project has provided homogeneous spectroscopic abundances of 290 Classical Cepheids (DCEPs) for which we have the intensity-averaged magnitudes in multiple optical and near-infrared (NIR) bands, periods, pulsation modes, and Gaia parallaxes. Our goal is to derive updated period--Wesenheit--metallicity (PWZ) relations using the largest and most homogeneous metallicity sample ever used for such analyses, covering a range of $-1.3<$[Fe/H]$<+0.3$ dex. We computed several optical and NIR Wesenheit magnitudes using 275 DCEPs with reliable parallaxes, by applying a robust photometric parallax technique, which simultaneously fits all parameters -- including the global Gaia parallax counter-correction -- and handles outliers without data rejection. We find a stronger metallicity dependence ($γ\approx -0.5$ mag/dex in optical, $-0.4$ mag/dex in NIR) than recent literature reports. Gaia parallax zero-point conter-corrections ($ε$) vary smoothly across bands, with an average value of $\sim$10 $μ$as, aligning with previous determinations. Applying our PWZ relations to LMC Cepheids yields distances generally consistent within $1σ$ with geometric estimates. The choice of reddening law has a negligible impact, while using only fundamental-mode pulsators significantly increases the uncertainties. Including $α$-element corrections increases $|γ|$ and reduces $ε$. However, we find statistically consistent $γ$ values with the literature, particularly for the key Wesenheit magnitude in the HST bands, by restricting the sample to the brighter (i.e. closer) objects, or by including only pulsators with $-0.7<$[Fe/H]$<$0.2 dex. Our results hint at a large $γ$ or a non-linear dependence on metallicity of DCEP luminosities at the metal-poor end, which is difficult to quantify with the precision of parallaxes of the present dataset.

We generalize the framework of spurion analysis to a class of selection rules arising from non-invertible fusion algebras in perturbation theory. As a first step toward systematic applications to particle physics, we analyze the near-group fusion algebras, defined by fusion rules built from a finite Abelian group $G$ extended by a single non-invertible element. Notable examples include the Fibonacci and Ising fusion rules. We introduce a systematic scheme for labeling coupling constants at the level of the non-invertible fusion algebra, enabling consistent tracking of couplings when constructing composite amplitudes from simpler building blocks. Our labeling provides a clear interpretation of why the tree-level exact non-invertible selection rules are violated through radiative corrections, a unique phenomenon essential to ``loop-induced groupification''. We also identify the limit where the near-group fusion algebra is lifted to a $G\times \mathbb{Z}_2$ group, which provides an alternative scheme of spurion analysis consistent with the original one based on the near-group algebra. Meanwhile, we highlight the distinctions between the selection rules imposed by the near-group fusion algebra and those from breaking the $G\times \mathbb{Z}_2$ group.

We present ProMage, a feed-forward neural network that emulates the computation of observer- and rest-frame magnitudes from the generative galaxy SED package ProSpect. The network predicts magnitudes conditioned on input galaxy physical properties, including redshift, star formation history, gas and dust parameters. ProMage accelerates magnitude computation by a factor of $10^4$ compared to ProSpect, while achieving per-mille relative accuracy for $99\%$ of sources in the test set across the $g,r,i,z,y$ Hyper Suprime-Cam bands. This acceleration is key to enabling fast inference of galaxy physical properties in next-generation Stage IV surveys and to generating large catalogue realisations in forward-modelling frameworks such as GalSBI-SPS.

Various so-called anomalies have been found in both the WMAP and Planck cosmic microwave background (CMB) temperature data that exert a mild tension against the highly successful best-fit 6 parameter cosmological model, potentially providing hints of new physics to be explored. That these are real features on the sky is uncontested. However, given their modest significance, whether they are indicative of true departures from the standard cosmology or simply statistical excursions, due to a mildly unusual configuration of temperature anisotropies on the sky which we refer to as the "fluke hypothesis", cannot be addressed further without new information. No theoretical model of primordial perturbations has to date been constructed that can explain all of the temperature anomalies. Therefore, we focus in this paper on testing the fluke hypothesis, based on the partial correlation between the temperature and $E$-mode CMB polarisation signal. In particular, we compare the properties of specific statistics in polarisation, built from unconstrained realisations of the $Λ$CDM cosmological model as might be observed by the LiteBIRD satellite, with those determined from constrained simulations, where the part of the $E$-mode anisotropy correlated with temperature is constrained by observations of the latter. Specifically, we use inpainted Planck 2018 SMICA temperature data to constrain the $E$-mode realisations. Subsequent analysis makes use of masks defined to minimise the impact of the inpainting procedure on the $E$-mode map statistics. We find that statistical assessments of the $E$-mode data alone do not provide any evidence for or against the fluke hypothesis. However, tests based on cross-statistical measures determined from temperature and $E$ modes can allow this hypothesis to be rejected with a moderate level of probability.

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 slight changes in this threshold also explored) in the Milky Way subject to be followed up by future massive spectroscopic surveys, we have developed a Gaia DR3 plus literature data based methodology. We trained a Balanced Random Forest (BRF) with the spectral types from the compilation by Skiff et al. (2014) as labels. Our approach yields a completeness of $\sim80\%$ and a purity ranging from $0.51 \pm 0.02$ for probabilities between 0.6 and 0.7, up to $0.85 \pm 0.05$ 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 in 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 $\sim$50\%. As a byproduct, we developed an automatic methodology for spectral typing optimized for LAMOST spectra, based on line detection and characterization guiding a decision path.

The thermal confinement phase transition (PT) in $SU(N)$ Yang-Mills theory is first-order for $N\geq 3$, with bounce action scaling as $N^2$. Remarkably, lattice data for the action include a small coefficient whose presence likely strongly alters the PT dynamics. We give evidence, utilizing insights from softly-broken SUSY YM models, that the small coefficient originates from a deconfined phase instability just below the critical temperature. We predict the maximum achievable supercooling in $SU(N)$ theories to be a few percent, which can be tested on the lattice. We briefly discuss the potentially significant suppression of the associated cosmological gravitational wave signals.

Many galactic globular clusters (GCs) contain at least two stellar populations. Recent observational studies found that the radial distributions of the first (P1) and second population (P2) differ in dynamically-young GCs. Since P2 is conventionally assumed to form more centrally concentrated, the rapid mixing (or even inversion) in some GCs but not others is puzzling. We investigate whether dynamical processes specific to certain GCs might cause this. Specifically, we evaluate the expansion of P2 by binary-single interactions in the cluster core and whether these can mix the P1/P2 radial distributions, using a set of toy-models with varying numbers and masses of primordial binaries. We find that even one massive binary star can push the central P2 outwards, but multiple binaries are required to fully mix P1 and P2 within a few relaxation times. We also compare our results to observed properties of mixed young GCs (NGC 4590, 5053, or 5904).

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 (MS) or red giant (RG) 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 $\sim5-45$ ($\sim1-8$) detectable UCXBs in the Milky Way (Andromeda galaxy), including $\sim1$ 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 $\sim 10^3$ 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 study the approach to equilibrium of bottomonium in the quark-gluon plasma within the open quantum system framework. We perform large-scale simulations of the long-time behavior in three dimensions using the quantum trajectory method to observe the emergence of steady states and determine the timescale of thermalization in position-, angular-momentum-, and color-space. We find that the thermalization timescale increases with decreasing temperature and decreasing coupling to the medium, which is given by transport coefficients of the medium. Additionally, we observe that the steady states exhibit small corrections to the Gibbs state due to medium interactions and show that these corrections diminish for weaker medium coupling and higher temperature. At a temperature of $450\,$MeV, quarkonium relaxes to a state that is approximately thermal, with the most significant correction being a smaller overlap of the $1S$ state with respect to the Gibbs state. We compare these findings with the master equation obtained at leading order in the expansion of the binding energy over the temperature, which we find to have a trivial steady state.

Our recent works [1,2] revisit the proof of chiral symmetry breaking in the confining regime of four-dimensional QCD-like theories, i.e. <mml:math><mml:mi>S</mml:mi><mml:mi>U</mml:mi><mml:mo>(</mml:mo><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub><mml:mo>)</mml:mo></mml:math> gauge theories with <mml:math><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>f</mml:mi></mml:mrow></mml:msub></mml:math> flavors of vectorlike quarks in the fundamental representation. The analysis relies on the structure of 't Hooft anomaly matching and persistent mass conditions for theories with same <mml:math><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub></mml:math> and different <mml:math><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>f</mml:mi></mml:mrow></mml:msub></mml:math>. In this paper, we work out concrete examples with <mml:math><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>3</mml:mn></mml:math> and <mml:math><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>5</mml:mn></mml:math> to support and elucidate the results of [1,2]. Within the same examples, we also test some claims made in earlier works.

A unique galaxy at z = 2.2, zC406690, has a striking clumpy large-scale ring structure that persists from rest-frame UV to near-infrared, yet has an ordered rotation and lies on the star formation main sequence. We combine new JWST/NIRCam and Atacama Large Millimeter/submillimeter Array (ALMA) band 4 observations, together with previous Very Large Telescope/SINFONI integral field spectroscopy and Hubble Space Telescope imaging to reexamine its nature. The high-resolution Hα kinematics is best fitted if the mass is distributed within a ring with total mass M_ring ≈ 2 × 10¹⁰ M_⊙ and radius R_ring = 4.6 kpc, together with a central undetected mass component (e.g., a "bulge") with a dynamical mass of M_bulge = 8 × 10¹⁰ M_⊙. We also consider a purely flux-emitting ring superposed over a faint exponential disk, or a highly "cuspy" dark matter halo, both disfavored against a massive ring model. The low-resolution CO(4–3) line and 142 GHz continuum emission imply total molecular and dust gas masses of M_mol,gas = 7.1 × 10¹⁰ M_⊙ and M_dust = 3 × 10⁸ M_⊙, respectively, over the entire galaxy, giving a dust-to-gas ratio of 0.7%. We estimate that roughly half the gas and dust mass lie inside the ring, and that ∼10% of the total dust is in a foreground screen that attenuates the stellar light of the bulge in the rest-frame UV to near-infrared. Sensitive high-resolution ALMA observations will be essential to confirm this scenario and study the gas and dust distribution.

We present a global neutrino oscillation analysis of models with a single large extra dimension in which right-handed neutrinos possess bulk Dirac masses. Two scenarios are considered: Large Extra Dimensions with bulk masses and the Dark Dimension framework, both predicting a tower of sterile Kaluza-Klein states that mix with active neutrinos. Using data from MINOS/MINOS+, KamLAND, and Daya Bay, we perform a joint likelihood analysis. No signatures of these theories were found. Therefore, we constrain the compactification radius under different bulk mass and Yukawa coupling assumptions. Large positive bulk masses or sizable Yukawas lead to strong bounds, while small couplings or negative bulk masses remain less constrained.

We present a microscopic model of the dark sector that resolves the Hubble tension within standard current datasets based on well-known fundamental principles, gauge symmetry and spontaneous symmetry breaking. It builds on the Hot New Early Dark Energy (Hot NEDE) setup, featuring a dark $SU(N)$ gauge symmetry broken to $SU(N-1)$ in a supercooled phase transition that creates a thermal bath of self-interacting dark radiation in the epoch between Big Bang Nucleosynthesis and recombination. Adding a fermion multiplet charged under the gauge symmetry provides a naturally stable component of dark matter that interacts with dark radiation. Spontaneous symmetry breaking predicts a decoupling of this interaction once the dark sector cools down, that we refer to as dark radiation matter decoupling (DRMD). We find agreement between the SH${}_0$ES determination of $H_0$ as well as combined Planck 2018, Pantheon+ and DESI baryon acoustic oscillation (BAO) data at 1.4$σ$ level, compared to a 5.7$σ$ tension in the $Λ$ Cold Dark Matter model. We also provide a simplified three-parameter DRMD model encoding the essential features, while the full model offers additional falsifiable predictions.

We study the scaling relation between the black hole and stellar mass ($M_\bullet-M_*$), diagnosing the residual $Δ\log(M_\bullet/M_\odot)$ ($Δ$) in this relation to understand the coevolution of the galaxy and black hole (BH) in the cosmological hydrodynamic simulation SIMBA. We showed that SIMBA can reproduce the observed $M_\bullet-M_*$ relation well with little difference between central and satellite galaxies. By using the median value to determine the residuals, we found that the residual is correlated with galaxy cold gas content, star formation rate, colour and black hole accretion properties. Both torque and Bondi models implemented in SIMBA, contribute to this residual, with torque accretion playing a major role at high redshift and low-mass galaxies, while Bondi (also BH merge) takes over at low redshift and massive galaxies. By dividing the sample into two populations: $Δ>0$ and $Δ<0$, we compared their evolution paths following the main progenitors. With evolution tracking, we proposed a simple picture for the BH-galaxy coevolution: Early-formed galaxies seeded black holes earlier, with stellar mass increasing rapidly to quickly reach the point of triggering `jet mode' feedback. This process reduced the cold gas content and stopped the growth of $M_*$, effectively quenching galaxies. Meanwhile, during the initial phase of torque accretion growth, the BH mass is comparable between galaxies formed early and those formed later. However, those galaxies that formed earlier appear to attain a marginally greater BH mass when shifting to Bondi accretion, aligning with the galaxy transition time. As the early-formed galaxies reach this point earlier -- leaving a longer time for them to have Bondi accretion as well as merging, their residuals become positive, i.e., having more massive BHs at $z=0$ compared to these late-formed galaxies at the same $M_*$. This picture is further supported by the strong positive correlation between the residuals and the galaxy age, which we are proposing as a verification with observation data on this story suggested by SIMBA.

Understanding the ages of stars is crucial for unraveling the formation history and evolution of our Galaxy. Traditional methods for estimating stellar ages from spectroscopic data often struggle with providing appropriate uncertainty estimations and are severely constrained by the parameter space. In this work, we introduce a new approach using normalizing flows—a type of deep generative model—to estimate stellar ages for evolved stars with improved accuracy and robust uncertainty characterization. The model is trained on stellar masses for evolved stars derived from asteroseismology and predicts the relationship between the carbon and nitrogen abundances of a given star and its age. Unlike standard neural network techniques, normalizing flows enable the recovery of full likelihood distributions for individual stellar ages, offering a richer and more informative perspective on uncertainties. Our method yields age estimations for 378,720 evolved stars and achieves a typical absolute age uncertainty of approximately 2 Gyr. By intrinsically accounting for the coverage and density of the training data, our model ensures that the resulting uncertainties reflect both the inherent noise in the data and the completeness of the sampled parameter space. Applying this method to data from the fifth-generation Sloan Digital Sky Survey Milky Way Mapper, we have produced the largest stellar age catalog for evolved stars to date.

A set of data from 68 cryogenic detectors operated in the CRESST dark matter search experiment between 2013 and 2019 was collected and labeled to train binary classifiers for data cleaning. Here, we describe the data set and how the trained models can be applied to new data. The data and models are available online.

In order to compress and more easily interpret Lyman-$α$ forest (Ly$α$F) datasets, summary statistics, e.g. the power spectrum, are commonly used. However, such summaries unavoidably lose some information, weakening the constraining power on parameters of interest. Recently, machine learning (ML)-based summary approaches have been proposed as an alternative to human-defined statistical measures. This raises a question: can ML-based summaries contain the full information captured by traditional statistics, and vice versa? In this study, we apply three human-defined techniques and one ML-based approach to summarize mock Ly$α$F data from hydrodynamical simulations and infer two thermal parameters of the intergalactic medium, assuming a power-law temperature-density relation. We introduce a metric for measuring the improvement in the figure of merit when combining two summaries. Consequently, we demonstrate that the ML-based summary approach not only contains almost all of the information from the human-defined statistics, but also that it provides significantly stronger constraints by a ratio of better than 1:3 in terms of the posterior volume on the temperature-density relation parameters.

We present a microscopic model of the dark sector that resolves the Hubble tension within standard current datasets based on well-known fundamental principles, gauge symmetry and spontaneous symmetry breaking. It builds on the Hot New Early Dark Energy (Hot NEDE) setup, featuring a dark $SU(N)$ gauge symmetry broken to $SU(N-1)$ in a supercooled phase transition that creates a thermal bath of self-interacting dark radiation in the epoch between Big Bang Nucleosynthesis and recombination. Adding a fermion multiplet charged under the gauge symmetry provides a naturally stable component of dark matter that interacts with dark radiation. Spontaneous symmetry breaking predicts a decoupling of this interaction once the dark sector cools down, that we refer to as dark radiation matter decoupling (DRMD). We find agreement between the SH${}_0$ES determination of $H_0$ as well as combined Planck 2018, Pantheon+ and DESI baryon acoustic oscillation (BAO) data at 1.4$σ$ level, compared to a 5.7$σ$ tension in the $Λ$ Cold Dark Matter model. We also provide a simplified three-parameter DRMD model encoding the essential features, while the full model offers additional falsifiable predictions.

Effective Field Theories (EFTs) have become indispensable tools for physics beyond the

Standard Model (BSM) to parameterize new physics in a model-independent way. To

obtain consistent predictions, the underlying assumptions have to be specified, and the

EFT has to be applied systematically. For BSM physics, two particular EFTs are widely

used: the Standard Model Effective Field Theory (SMEFT) and the electroweak chiral

Lagrangian, often referred to as the Higgs Effective Field Theory (HEFT). These two

approaches are based on distinct organizing principles. This thesis is dedicated to inves-

tigating the systematic application of both frameworks. For SMEFT, we argue that a power-counting scheme based solely on canonical dimensions is insufficient. It must be supplemented by a loop-order counting scheme, conveniently expressed through the assignment of chiral dimensions. By accounting for both canonical and chiral dimensions, a clear hierarchical structure emerges among the operators, enabling a more meaningful identification of potentially dominant contributions in high-energy processes. As a concrete example, we explore the interplay between these two

counting schemes by matching the Two-Higgs Doublet Model (2HDM) to SMEFT in the

decoupling limit. [...]

Two detector modules with lithium aluminate targets were operated in the CRESST underground setup between February and June 2021. The data collected in this period was used to set the currently strongest cross-section upper limits on the spin-dependent interaction of dark matter (DM) with protons and neutrons for the mass region between 0.25 and 1.5 GeV/c$^2$. The data are available online. In this document, we describe how the data set should be used to reproduce our dark matter results.

A flux of ultra-high-energy (UHE) neutrinos is generally expected to be produced by astrophysical sources at cosmological distances and to reach Earth. In this paper, we investigate the impact of neutrino scattering with dark matter (DM) particles in both the intergalactic medium and the Milky Way on the total flux, energy spectrum, and arrival directions of UHE neutrinos. We emphasize the complementarity of neutrino detectors at different latitudes to probe the anisotropy in the flux at Earth due to the attenuation of the neutrino flux in the Milky Way dark matter halo. We also discuss that, with mild astrophysical assumptions, limits on the DM-$ν$ scattering cross section can be placed even if the neutrino sources are unknown. Finally, we explore all this phenomenology with the recent UHE neutrino event KM3230213A, and place the corresponding limits in the DM-$ν$ scattering cross-section.

The majority of Galactic globular star clusters (GCs) have been reported to contain at least two populations of stars (we use P1 for the primordial and P2 for the chemically-enriched population). Recent observational studies found that dynamically-old GCs have P1 and P2 spatially mixed due to relaxation processes. However, in dynamically-young GCs, where P2 is expected to be more centrally concentrated from birth, the spatial distributions of P1 and P2 are sometimes very different from system to system. This suggests that more complex dynamical processes specific to certain GCs might have shaped those distributions. We aim to investigate the discrepancies between the spatial concentration of P1 and P2 stars in dynamically-young GCs. Our focus is to evaluate whether massive binary stars (e.g. BHs) can cause the expansion of the P2 stars through binary-single interactions in the core, and whether they can mix or even radially invert the P1 and P2 distributions. We use a set of theoretical and empirical arguments to evaluate the effectiveness of binary-single star scattering. We then construct a set of direct N-body models with massive primordial binaries to verify our estimates further and gain more insights into the dynamical processes in GCs. We find that binary-single star scatterings can push the central P2 stars outwards within a few relaxation times. While we do not produce radial inversion of P1 and P2 for any initial conditions we tested, this mechanism systematically produces clusters where P1 and P2 look fully mixed even in projection. The mixing is enhanced 1) in denser GCs, 2) in GCs containing more binary stars, and 3) when the mass ratio between the binary components and the cluster members is higher. Binary-single star interactions seem able to explain the observable properties of some dynamically-young GCs (e.g. NGC4590 or NGC5904) where P1 and P2 are fully radially mixed.

The motivic coaction of multiple zeta values and multiple polylogarithms encodes both structural insights on and computational methods for scattering amplitudes in a variety of quantum field theories and in string theory. In this work, we propose coaction formulae for iterated integrals over holomorphic Eisenstein series that arise from configuration-space integrals at genus one. Our proposal is motivated by formal similarities between the motivic coaction and the single-valued map of multiple polylogarithms at genus zero that are exposed in their recent reformulations via zeta generators. The genus-one coaction of this work is then proposed by analogies with the construction of single-valued iterated Eisenstein integrals via zeta generators at genus one. We show that our proposal exhibits the expected properties of a coaction and deduce $f$-alphabet decompositions of the multiple modular values obtained from regularized limits.

Self-assembly processes in biological and synthetic biomolecular systems are often governed by the spatial separation of biochemical processes. While previous work has focused on optimizing self-assembly through fine-tuned reaction parameters or using phase-separated liquid compartments with fast particle exchange, the role of slow inter-compartmental exchange remains poorly understood. Here, we demonstrate that slow particle exchange between reaction domains can enhance self-assembly efficiency through a cooperative mechanism: delay-facilitated assembly. Using a minimal model of irreversible self-assembly in two compartments with distinct reaction and exchange dynamics, we identify scenarios that maximize yield and minimize assembly time, even under conditions where isolated compartments would fail to facilitate any self-assembly. The mechanism relies on a separation of timescales between intra-compartmental reactions and inter-compartmental exchange and is robust across a wide range of geometries, including spatially extended domains with diffusive transport. We demonstrate that this effect enables geometric control of self-assembly processes through compartment volumes and exchange rates, eliminating the need for fine-tuning local reaction rates. These results offer a conceptual framework for leveraging spatial separation in synthetic self-assembly design and suggest that biological systems may use slow particle exchange to improve assembly efficiency.

Electroweakly interacting stable spin-1 particle in the (1-10) TeV mass range can be a dark matter candidate with rich testability. In particular, one or even two gamma-ray line-like features are expected to be a smoking-gun signature for indirect detection in this scenario. The presence of large Sudakov logarithmic corrections, though, significantly complicates the theoretical prediction of the gamma-ray spectrum. We resum these corrections at the next-to-leading-log (NLL) accuracy using Soft-Collinear Effective field Theory (SCET). Rather interestingly, we find that the LL- and NLL-resummed endpoint spectra for this model are, up to an overall factor, identical to already existing calculations in the contexts of spin-0 and spin-1/2 (i.e. wino-like) scenarios. We discuss how this non-trivial "exact universality" irrespective of DM spin at these accuracies comes about despite the completely different SCET operator bases. Our resummations allow us to reduce the uncertainty, demonstrated in the energy spectrum with distinctive two peaks from annihilations into γγ, Zγ channel and a photon with Z ₂-even extra heavy neutral boson Z ^'. We discuss the prospect of improving accuracy further, which is crucial for the heavier DM mass region and realistic resolution in future gamma-ray observations.

Context. Intermediate neutron-capture processes are thought to occur in stellar environments where protons are ingested into a hot helium-burning convective region. It has been shown that proton ingestion episodes can happen in the formation of hot-subdwarf stars, and that neutron-capture processes are possible in those cases. Moreover, some helium-rich hot subdwarfs display extraordinarily high abundances of heavy elements such as Zr, Yr, and Pb on their surfaces. These elements can be produced by both slow and intermediate neutron-capture processes. Aims. We explore under which conditions neutron-capture processes can occur in late helium core flashes, that is, those occurring in the cores of stripped red-giant stars. We explore the dependence of such processes on the metallicity of the star, and how much the star is stripped before the He flash takes place. Methods. We computed evolutionary models through the helium core flash and the subsequent hydrogen ingestion episode in stripped red-giant stars. Stellar structure models were then used in post-processing to compute the detailed evolution of neutron-capture elements. Results. We find that for metallicities of 10^‑3 and below, neutron densities can be as high as 10¹⁵ cm^‑3 and intermediate neutron-capture processes occur in some of our models. The results depend very strongly on the H-envelope mass that survives after the stripping, which alters the nucleosynthesis during the flashes, and therefore the behavior of the convective motions. Interestingly, we find that computed abundances in some of our models closely match the element abundances up to tin observed for EC 22536-5304, the only well-studied star for which the hot-flasher scenario assumed in our models is the most likely evolutionary path. Conclusions. Intermediate neutron-capture processes can occur in the He-core flash experienced by the cores of some stripped red giants, and this might be connected to the abundances of heavy elements observed in some helium-rich hot-subdwarf stars. The agreement between the observed abundances in EC 22536-5304 and those of our models offers support to our nucleosynthesis calculations. Moreover, if confirmed, the idea that heavy element abundances retain signatures of the different evolutionary channels opens the possibility that heavy element abundances in iHe-sdOB stars can be used to infer their evolutionary origin.

The relativistic <mml:math><mml:msub><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mrow><mml:mrow><mml:mi>low</mml:mi></mml:mrow><mml:mspace></mml:mspace><mml:mi>k</mml:mi></mml:mrow></mml:msub></mml:math> is developed from a renormalization group method for the first time, to provide softened NN interactions for relativistic <mml:math><mml:mi>a</mml:mi><mml:mi>b</mml:mi><mml:mspace></mml:mspace><mml:mi>i</mml:mi><mml:mi>n</mml:mi><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:mi>i</mml:mi><mml:mi>o</mml:mi></mml:math> calculations. Starting from a given bare NN interaction, the renormalization group method eliminates the repulsive core while keeping the low-energy on-shell T-matrix and, consequently, the two-body observables unchanged. We derive the relativistic <mml:math><mml:msub><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mrow><mml:mrow><mml:mi>low</mml:mi></mml:mrow><mml:mspace></mml:mspace><mml:mi>k</mml:mi></mml:mrow></mml:msub></mml:math> interactions from the relativistic Bonn NN interactions across a wide range of cutoffs and study nuclear matter using the relativistic Brueckner-Hartree-Fock theory in the full Dirac space. Our results demonstrate that the resulting relativistic <mml:math><mml:msub><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mrow><mml:mrow><mml:mi>low</mml:mi></mml:mrow><mml:mspace></mml:mspace><mml:mi>k</mml:mi></mml:mrow></mml:msub></mml:math> interactions provide a proper description of nuclear saturation, exhibiting only mild cutoff dependence. Therefore, the relativistic <mml:math><mml:msub><mml:mrow><mml:mi>V</mml:mi></mml:mrow><mml:mrow><mml:mrow><mml:mi>low</mml:mi></mml:mrow><mml:mspace></mml:mspace><mml:mi>k</mml:mi></mml:mrow></mml:msub></mml:math> shows promise for providing reliable softened NN interactions for future relativistic <mml:math><mml:mi>a</mml:mi><mml:mi>b</mml:mi><mml:mspace></mml:mspace><mml:mi>i</mml:mi><mml:mi>n</mml:mi><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:mi>i</mml:mi><mml:mi>o</mml:mi></mml:math> calculations of finite nuclei.

Context. The multitude of different architectures found for evolved exoplanet systems are in all likelihood set during the initial planet-formation phase in the circumstellar disk. To understand this process, we have to study the earliest phases of planet formation. Aims. Complex sub-structures, believed to be driven by embedded planets, have been detected in a significant portion of the disks observed at high angular resolution. We aim to extend the sample of such disks to low stellar masses and to connect the disk morphology to the expected proto-planet properties. Methods. In this study, we used VLT/SPHERE to obtain resolved images on the scale of ∼10 au of the circumstellar disk in the 2MASSJ16120668-3010270 system in polarized scattered light. We searched for the thermal radiation of recently formed gas giants embedded in the disk. Additionally, we used VLT/XSHOOTER to obtain the stellar properties in the system. Results. We resolve the disk in the 2MASSJ16120668-3010270 system for the first time in scattered near-infrared light and reveal an exceptionally structured disk. We find an inner disk (reaching out to 40 au) with two spiral arms, separated by a gap from an outer ring extending to 115 au. By comparison with our own model and hydrodynamic models from the literature, we find that these structures are consistent with the presence of an embedded gas giant with a mass range between 0.1 M_Jup and 5 M_Jup depending on the employed model and their underlying assumptions. Our SPHERE observations find a tentative candidate point source within the disk gap, the brightness of which would be consistent with this mass range if it indeed traces thermal emission by an embedded planet. This interpretation is somewhat strengthened by the proximity of this signal to compact millimeter continuum emission in the disk gap, which may trace circumplanetary material. It is, however, unclear if this tentative companion candidate could be responsible for the observed disk gap size, given its close proximity to the inner disk. Generally, our VLT/SPHERE observations set an upper limit of ∼5 M_Jup in the disk gap (∼0.2"‑0.5"), consistently with our modeling results. The 2MASSJ16120668-3010270 system is one of only a few systems that shows this exceptional morphology of spiral arms located inside a scattered light gap and ring. We speculate that this may have to do with a higher disk viscosity compared with other systems such as PDS 70. If planets in the disk are confirmed, 2MASSJ16120668-3010270 will become a prime laboratory for the study of planet-disk interaction. ★Based on observations made with ESO telescopes at the La Silla Paranal Observatory under program IDs 111.255B.001, 1104.C-0415(D) and 109.23BC.001.

We apply population synthesis techniques to analyze TYPHOON long slit spectra of the starburst barred spiral galaxy M83. The analysis covers a central square of 5' side length. We determine the spatial distribution of dust through the analysis of reddening and extinction, together with star formation rates, ages, and metallicities of young and old stellar populations. For the first time, a spatial one-to-one comparison of metallicities derived from full spectral fitting techniques with those obtained from individual young stellar probes has been carried out. The comparison with blue supergiant stars, young massive star clusters, and super star clusters shows a high degree of concordance when wavelength coverage in the B band is available. The metallicity of the young population is supersolar and does not show a radial metallicity gradient along the investigated part of the disk, in agreement with our chemical evolution model. However, a notable decrease in metallicity is observed in a tightly confined region at the galaxy center, coinciding with circumnuclear orbits. We attribute this to matter infall either from the circumgalactic medium, a dwarf galaxy interloper, or, alternatively, to active-galactic-nucleus-interrupted chemical evolution. We confirm the presence of a dust cavity with a diameter of 260 pc close to the galaxy center. Dust absorption and molecular CO emission are spatially well correlated. We find an anticorrelation between R_V, the ratio of dust attenuation to reddening, and the emission strength of molecular species present in photodissociation regions. We confirm our results by using alternative fitting algorithms and stellar libraries.

At any given scale, 3$\times$2-point statistics extract only three numbers from the joint distribution of the cosmic matter density and galaxy density fluctuations: their variances and their covariance. It is well known that the full shape of the PDF of those fluctuations contains significantly more information than can be accessed through these three numbers. But the study of the PDF of cosmic density fluctuations in real observational data is still in its infancy. Here we present \verb|CosMomentum|, a public software toolkit for calculating theoretical predictions for the full shape of the joint distribution of a line-of-sight projected tracer density and the gravitational lensing convergence. We demonstrate that an analysis of this full shape of the PDF can indeed disentangle complicated tracer bias and stochasticity relations from signatures of cosmic structure growth. Our paper also provides back-drop for an upcoming follow-up study, which prepares PDF analyses for application to observational data by incorporating the impact of realistic weak lensing systematics.