The R³B (Reactions with Relativistic Radioactive Beams) experiment as a major instrument of the NUSTAR collaboration for the research facility FAIR in Darmstadt is designed for kinematically complete studies of reactions with high-energy radioactive beams. Part of the broad physics program of R³B is to constrain the asymmetry term in the nuclear equation-of-state and hence improve the description of highly asymmetric nuclear matter (e.g., in neutron stars). For a precise determination of the neutron-skin thickness – an observable which is directly correlated with the symmetry energy in theoretical calculations – by measuring absolute fragmentation cross sections, it is essential to quantify the uncertainty and challenge the reaction model under stable conditions. During the successful FAIR Phase-0 campaign of R³B, we precisely measured the energy dependence of total interaction cross sections in ¹²C+¹²C collisions, for a direct comparison with calculations based on the eikonal reaction theory.

We compute the partition function for the $N=1$ spinning particle, including pictures and the large Hilbert space, and show that it counts the dimension of the BRST cohomology in two- and four-dimensional target space. We also construct a quadratic action in the target space. Furthermore, we find a consistent interaction as a derived bracket based on the associative product of world line fields, leading to an interacting theory of multiforms in space-time. Finally, we comment on the equivalence of the multiform theory with a Dirac fermion. We also identify the chiral anomaly of the latter with a Hodge anomaly for the multiform theory, which manifests itself as a deformation of the gauge fixing.

So far, even the highest resolution galaxy formation simulations with gravitational softening have failed to reproduce realistic life cycles of star clusters. We present the first star-by-star galaxy models of star cluster formation to account for hydrodynamics, star formation, stellar evolution, and collisional gravitational interactions between stars and compact remnants using the updated SPHGAL + KETJU code, part of the GRIFFIN project. Gravitational dynamics in the vicinity of <inline-formula><tex-math id="TM0001" notation="LaTeX">$>3$</tex-math></inline-formula> M<inline-formula><tex-math id="TM0002" notation="LaTeX">$_\odot$</tex-math></inline-formula> stars and their remnants are solved with a regularized integrator (KETJU) without gravitational softening. Comparisons of idealized star cluster evolution with SPHGAL + KETJU and direct N-body show broad agreement and the failure of simulations that use gravitational softening. In the hydrodynamical simulations of idealized dwarf galaxies run with SPHGAL + KETJU, clusters up to <inline-formula><tex-math id="TM0003" notation="LaTeX">$\sim 900$</tex-math></inline-formula> M<inline-formula><tex-math id="TM0004" notation="LaTeX">$_\odot$</tex-math></inline-formula> form compact (effective radii 0.1-1 pc) and their sizes increase by up to a factor of 10 in agreement with previous N-body simulations and the observed sizes of exposed star clusters. The sizes increase rapidly once the clusters become exposed due to photoionizing radiation. On average 63 per cent of the gravitationally bound clusters disrupt during the first 100 Myr of evolution in the galactic tidal field. The addition of collisional dynamics reduces the fraction of supernovae in bound clusters by a factor of <inline-formula><tex-math id="TM0005" notation="LaTeX">$\sim 1.7$</tex-math></inline-formula>; however, the global star formation and outflow histories change by less than 30 per cent. We demonstrate that the accurate treatment of gravitational encounters with massive stars enables more realistic star cluster life cycles from the earliest stages of cluster formation until disruption in simulated low-mass galaxies.

Galaxy and halo scaling relations, connecting a broad range of parameters, are well established from observations. The origin of many of these relations and their scatter is still a matter of debate. It remains a sizable challenge for models to simultaneously and self-consistently reproduce as many scaling relations as possible. We introduce the Magneticum Pathfinder hydrodynamical cosmological simulation suite, to date the suite that self-consistently covers the largest range in box volumes and resolutions. It is the only cosmological simulation suite that is tuned on the hot gas content of galaxy clusters instead of the stellar mass function. By assessing the successes and shortcomings of tuning to the hot gas component of galaxy clusters, we aim to further our understanding of the physical processes shaping the Universe. We analyze the importance of the hot and cold gas components for galaxy and structure evolution. We analyze 28 scaling relations, covering large-scale global parameters as well as internal properties for halos ranging from massive galaxy clusters down to galaxies, and show their predicted evolution from z=4 to z=0 in comparison with observations. These include the halo-to-stellar-mass and Kennicutt--Schmidt relations, the cosmic star formation rate density as well as the Fundamental Plane. Magneticum Pathfinder matches a remarkable number of the observed scaling relations from z=4 to z=0, including challenging relations like the number density of quiescent galaxies at cosmic dawn, the mass--size evolution, the mass--metallicity relation, the Magorrian relation, and the temperature--mass relation. We compile our data to allow for straightforward future comparisons. Galaxy properties and scaling relations arise naturally and the large scatter in observables at high redshift is crucial to distinguish the various galaxy formation models reproducing the z=0 relations.

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.

Future telescopes will characterize rocky exoplanets in reflected light, revealing their albedo, which depends on surface, cloud, and atmospheric properties. Identifying these features is crucial for assessing habitability. We present reference spectra and phase curves for an unresolved Earth-like exoplanet in reflected and polarized light, showing how phase- and wavelength-dependent reflectance reveals key planetary properties. Using the 3D radiative transfer code MYSTIC, we enhance surface and cloud modeling with validated, wavelength-dependent albedo maps of Earth's seasonal and spectral features, alongside a novel treatment of sub-grid cloud variability using ERA5 reanalysis data. Our models, incorporating high-resolution 3D cloud structures, show that sub-grid cloud variability reduces total reflectance and increases phase curve variability, especially at large phase angles where ocean glint dominates. We also find that neglecting wavelength-dependent albedo maps overestimates the vegetation red edge in spectra. Comparing an Ocean planet to an Earth-like planet with seasonal cloud variability, we show that polarization is more sensitive than intensity alone in distinguishing both cases. Moreover, polarization captures richer surface details, making it a crucial tool for resolving retrieval degeneracies. Our simulations serve as a reference for observing Earth as an exoplanet and provide benchmarks for optimizing observational strategies and retrieval frameworks for future telescopes targeting small, rocky exoplanets.

Among the well-known methods to approximate derivatives of expectancies computed by Monte-Carlo simulations, averages of pathwise derivatives are often the easiest one to apply. Computing them via algorithmic differentiation typically does not require major manual analysis and rewriting of the code, even for very complex programs like simulations of particle-detector interactions in high-energy physics. However, the pathwise derivative estimator can be biased if there are discontinuities in the program, which may diminish its value for applications. This work integrates algorithmic differentiation into the electromagnetic shower simulation code HepEmShow based on G4HepEm, allowing us to study how well pathwise derivatives approximate derivatives of energy depositions in a sampling calorimeter with respect to parameters of the beam and geometry. We found that when multiple scattering is disabled in the simulation, means of pathwise derivatives converge quickly to their expected values, and these are close to the actual derivatives of the energy deposition. Additionally, we demonstrate the applicability of this novel gradient estimator for stochastic gradient-based optimization in a model example.

We show experimentally that an effect of motion of ions, observed in a plasma-based accelerator, depends inversely on the plasma ion mass. The effect appears within a single wakefield event and manifests itself as a bunch tail, occurring only when sufficient motion of ions suppresses wakefields. Wakefields are driven resonantly by multiple bunches, and simulation results indicate that the ponderomotive force causes the motion of ions. In this case, the effect is also expected to depend on the amplitude of the wakefields, experimentally confirmed through variations in the drive bunch charge.

We calculate two-loop renormalization group equations (RGEs) in the Standard Model Effective Field Theory (SMEFT) with right-handed neutrinos, i.e., the so-called $ν$SMEFT, up to dimension five. Besides the two-loop RGEs of dimension-five (dim-5) operators, we also present those of the renormalizable couplings, including contributions from dim-5 operators. We check consistency relations among the first and second poles of $\varepsilon \equiv (4-d)/2$ with $d$ being the space-time dimension for all renormalization constants and find that those for lepton doublet and right-handed neutrino wave-function renormalization constants, as well as for renormalization constants of charged-lepton and neutrino Yukawa coupling matrices, do not hold. This leads to divergent RG functions for these fields and Yuwawa coupling matrices. We figure out that such infinite RG functions arise from the non-invariance of fields and Yukawa coupling matrices under field redefinitions, considering that flavor transformations are a kind of linear field redefinitions. Those infinite RG functions will disappear once one restores contributions from the derivative of renormalization constants with respect to the Wilson coefficients of redundant operators or, alternatively, considers the RGEs of flavor invariants, which are physical quantities and remain invariant under field redefinitions.

We study stellar core growth in simulations of merging massive (<inline-formula><tex-math id="TM0001" notation="LaTeX">$M_\star \gt 10^{11}\, \mathrm{M}_{\odot }$</tex-math></inline-formula>) elliptical galaxies by a supermassive black hole (SMBH) displaced by gravitational wave induced recoil velocity. With controlled, dense sampling of the SMBH recoil velocity, we find the core radius originally formed by SMBH binary scouring can grow by a factor of 2-3 when the recoil velocity exceeds <inline-formula><tex-math id="TM0002" notation="LaTeX">$\sim 50$</tex-math></inline-formula> per cent of the central escape velocity, and the mass deficit grows by up to a factor of <inline-formula><tex-math id="TM0003" notation="LaTeX">$\sim 4$</tex-math></inline-formula>. Using Bayesian inference we predict the distribution of stellar core sizes formed through this process to peak at <inline-formula><tex-math id="TM0004" notation="LaTeX">$\sim 1\, \mathrm{kpc}$</tex-math></inline-formula>. An orbital decomposition of stellar particles within the core reveals that radial orbits dominate over tube orbits when the recoil velocity exceeds the velocity dispersion of the core, whereas tube orbits dominate for the lowest recoil kicks. A change in orbital structure is reflected in the anisotropy parameter, with a central tangential bias present only for recoil velocities less than the local stellar velocity dispersion. Emulating current integral field unit observations of the stellar line-of-sight velocity distribution, we uncover a distinct signature in the Gauss-Hermite symmetric deviation coefficient <inline-formula><tex-math id="TM0005" notation="LaTeX">$h_4$</tex-math></inline-formula> that uniquely constrains the core size due to binary scouring. This signature is insensitive to the later evolution of the stellar mass distribution due to SMBH recoil. Our results provide a novel method to estimate the SMBH recoil magnitude from observations of local elliptical galaxies, and implies these galaxies primarily experienced recoil velocities less than the stellar velocity dispersion of the core.

The synthesis of life from non-living matter has captivated and divided scientists for centuries. This bold goal aims at unraveling the fundamental principles of life and leveraging its unique features, such as its resilience, sustainability, and ability to evolve. Synthetic life represents more than an academic milestone—it has the potential to revolutionize biotechnology, medicine, and materials science. Although the fields of synthetic biology, systems chemistry, and biophysics have made great strides toward synthetic life, progress has been hindered by social, philosophical, and technical challenges, such as vague goals, misaligned interdisciplinary efforts, and incompletely addressing public and ethical concerns. Our perspective offers a roadmap toward the synthesis of life based on discussions during a 2-week workshop with scientists from around the globe.

We present a formulation of coherent states as of consistent quantum description of classical configurations in the Becchi-Rouet-Stora-Tyutin (BRST)-invariant quantization of electrodynamics. The quantization with proper gauge-fixing is performed on the vacuum of the theory, whereas other backgrounds are obtained as BRST-invariant coherent states. One of the key insights is the possibility of constructing the coherent states of pure-gauge configurations. This provides a coherent state understanding of topologically nontrivial configurations in gauge theories and makes a number of features, such as the suppression of transitions between topologically distinct sectors, very transparent at full quantum level. As an example, we construct the Nielsen-Olesen string as a BRST-invariant coherent state. The Abelian pure-gauge configurations can also be viewed as useful analogs for a set of space-times related by coordinate reparametrizations in general relativity.

Historically, various methods have been employed to understand the origin of the elements, including observations of elemental abundances which have been compared to Galactic Chemical Evolution (GCE) models. It is also well known that 1D Local Thermodynamic Equilibrium (LTE) measurements fail to accurately capture elemental abundances. Non-LTE (NLTE) effects may play a significant role, and neglecting them leads to erroneous implications in galaxy modelling. In this paper, we calculate 3D NLTE abundances of seven key iron-peak and neutron-capture elements (Mn, Co, Ni, Sr, Y, Ba, Eu) based on carefully assembled 1D LTE literature measurements, and investigate their impact within the context of the OMEGA+ GCE model. Our findings reveal that 3D NLTE abundances are significantly higher for iron-peak elements at [Fe/H] <-3, with (for the first time ever) [Ni/Fe] and (confirming previous studies) [Co/Fe] on average reaching 0.6-0.8 dex, and [Mn/Fe] reaching -0.1 dex, which current 1D core-collapse supernova (CCSN) models cannot explain. We also observe a slightly higher production of neutron-capture elements at low metallicities, with 3D NLTE abundances of Eu being higher by +0.2 dex at [Fe/H] =-3. 3D effects are most significant for iron-peak elements in the very metal-poor regime, with average differences between 3D NLTE and 1D NLTE reaching up to 0.15 dex. Thus, ignoring 3D NLTE effects introduces significant biases, so including them should be considered whenever possible.

We introduce a novel orbit superposition method designed to reconstruct the stellar density structure, kinematics, and chemical abundance distribution of the entire Milky Way by leveraging 6D phase-space information from its resolved stellar populations, limited by the spatial coverage of APOGEE DR17.

Central regions of nearby disc galaxies display a large variety of structures in their stellar and gas disc that illustrates the outcome of a complex and dynamic evolution. The most visible central structure inside the bar region is the inner molecular disc (the so-called Central Molecular Zone (CMZ) in the Milky Way). Recent observational campaigns have shown that those inner molecular discs have a typical size ranging from a few hundred parsecs to one kiloparsec and tend to appear at the centre of barred discs. The physical phenomena involved in the building, consumption (e.g., star formation) and long-term evolution of those inner gas structures are still strongly debated. It is commonly accepted that the bar plays a role in the fuelling of gas from the large few kiloparsec scale to the inner molecular disc region. However, the exact physical processes involved in the loss of gas angular momentum (e.g., gravitational torques, shear, feedback) and its transport to the centre are not fully understood. Moreover, inner gas discs are intermediate-scale structures which connect the large kiloparsec scale and the subparsec scale physics (e.g., stellar-driven feedback, magnetic torques) involved in the fuelling of the central supermassive black hole (SMBH). Therefore, those inner discs can be considered as ‘gas reservoirs’ and may be efficient suppliers of material for the flickering of the central black hole, the so-called Active Galactic Nuclei (AGN). [...]

This study presents a novel method using spin quantum sensors to explore temporal variations of fundamental constants, significantly expanding the frequency range and providing constraints on scalar dark matter.

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 SDSS-V Milky Way Mapper, we have produced the largest stellar age catalog for evolved stars to date.

We have carried out a systematic search for galaxy-scale lenses exploiting multi-band imaging data from the third public data release of the Hyper Suprime-Cam (HSC) survey with the focus on false-positive removal, after applying deep learning classifiers to all 110 million sources with i-Kron radius above 0.8". To improve the performance, we tested the combination of multiple networks from our previous lens search projects and found the best performance by averaging the scores from five of our networks. Although this ensemble network leads already to a false-positive rate (FPR) of 0.01% at a true-positive rate (TPR) of 75% on known real lenses, we have elaborated techniques to further clean the network candidate list before visual inspection. In detail, we tested the rejection using SExtractor and the modeling network from HOLISMOKES IX, which resulted together in a candidate rejection of 29% without lowering the TPR. We carried out a comprehensive multi-stage visual inspection involving eight individuals and identified 95 grade A (average grade G >2.5) and 503 grade B (2.5 >G >1.5) lens candidates, including 92 discoveries reported for the first time. This inspection also incorporated a novel environmental characterization using histograms of photometric redshifts. We publicly release the average grades, mass model predictions, and environment characterization of all visually inspected candidates, while including references for previously discovered systems, which makes this catalog one of the largest compilation of known lenses. The results demonstrate that (1) the combination of multiple networks enhances the selection performance and (2) both automated masking tools as well as modeling networks, which can be easily applied to hundreds of thousands of network candidates, help reduce the number of false positives that is the main limitation in lens search to date.

Context. Theoretical models of structure formation predict the presence of a hot gaseous atmosphere around galaxies. While this hot circumgalactic medium (CGM) has been observationally confirmed through UV absorption lines, the detection of its direct X-ray emission remains scarce. Recent results from the eROSITA collaboration have claimed the detection of the CGM out to the virial radius for a stacked sample of Milky Way-mass galaxies. Aims. We investigate theoretical predictions of the intrinsic CGM X-ray surface brightness (SB) using simulated galaxies and connect them to their global properties, such as the gas temperature, hot gas fraction, and stellar mass. Methods. We selected a sample of central galaxies from the ultra-high-resolution cosmological volume (48 cMpc h^‑1) of the Magneticum Pathfinder set of hydrodynamical cosmological simulations. We classified them as star-forming (SF) or quiescent (QU) based on their specific star formation rate (SFR). For each galaxy, we generated X-ray mock data using the X-ray photon simulator PHOX, from which we obtained SB profiles out to the virial radius for different X-ray emitting components; namely, gas, active galactic nuclei (AGNs), and X-ray binaries (XRBs). We fit a β-profile to the gas component of each galaxy and observed trends between its slope and global quantities of the simulated galaxy. Results. We found marginal differences among the average total SB profile in SF and QU galaxies beyond r > 0.05 R_vir. The relative contribution from hot gas exceeds 70% and is non-zero (≲10%) for XRBs in both galaxy types. At small radii (r < 0.05 R_vir), XRBs dominate the SB profile over the hot gas for QU galaxies. We found positive correlations between the galaxies' global properties and the normalization of their SB profiles. The fitted β-profile slope is correlated with the total gas luminosity, which, in turn, shows strong connections to the current accretion rate of the central supermassive black hole (SMBH). We found the halo scaling relations to be consistent with the literature.

We introduce an extension of the evolution mapping framework to cosmological models that include massive neutrinos. The original evolution mapping framework exploits a degeneracy in the linear matter power spectrum when expressed in ${\rm Mpc}$ units, which compresses its dependence on cosmological parameters into those that affect its shape and a single extra parameter $\sigma_{12}$, defined as the RMS linear variance in spheres of radius $12 {\rm Mpc}$. We show that by promoting the scalar amplitude of fluctuations, $A_{\rm s}$, to a shape parameter, we can additionally describe the suppression due to massive neutrinos at any redshift to sub-0.01\% accuracy across a wide range of masses and for different numbers of mass eigenstates. This methodology has been integrated into the public COMET package, enhancing its ability to emulate predictions of state-of-the-art perturbative models for galaxy clustering, such as the effective field theory (EFT) model. Additionally, the updated software now accommodates a broader cosmological parameter space for the emulator, enables the simultaneous generation of multiple predictions to reduce computation time, and incorporates analytic marginalisation over nuisance parameters to expedite posterior estimation. Finally, we explore the impact of different infrared resummation techniques on galaxy power spectrum multipoles, demonstrating that any discrepancies can be mitigated by EFT counterterms without impacting the cosmological parameters.

Solid-state phonon and charge detectors probe the scattering of weakly interacting particles, such as dark matter and neutrinos, through their low recoil thresholds. Recent advancements have pushed sensitivity to eV-scale energy depositions, uncovering previously-unseen low-energy excess backgrounds. While some arise from known processes such as thermal radiation, luminescence, and stress, others remain unexplained. This review examines these backgrounds, their possible origins, and parallels to low-energy effects in solids. Their understanding is essential for interpreting particle interactions at and below the eV-scale.

Dark matter (DM) environments around black holes (BHs) can influence their mergers through dynamical friction, causing gravitational wave (GW) dephasing during the inspiral phase. While this effect is well studied for collisionless dark matter (CDM), it remains unexplored for self-interacting dark matter (SIDM) due to the typically low DM density in SIDM halo cores. In this work, we show that SIDM models with a massive force mediator can support dense enough DM spikes, significantly affecting BH mergers and producing a distinct GW dephasing. Using ${N}$-body simulations, we analyze GW dephasing in binary BH inspirals within CDM and SIDM spikes. By tracking the binary's motion in different SIDM environments, we show that the Laser Interferometer Space Antenna (LISA) can distinguish DM profiles shaped by varying DM interaction strengths, revealing detailed properties of SIDM.

We demonstrate that chiral symmetry breaking occurs in the confining regime of QCD-like theories with <mml:math altimg="si1.svg"><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub></mml:math> colors and <mml:math altimg="si2.svg"><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. Our proof is based on a novel strategy, called 'downlifting', by which solutions of the 't Hooft anomaly matching and persistent mass conditions for a theory with <mml:math altimg="si3.svg"><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>f</mml:mi></mml:mrow></mml:msub><mml:mo linebreak="goodbreak" linebreakstyle="after">‑</mml:mo><mml:mn>1</mml:mn></mml:math> flavors are constructed from those of a theory with <mml:math altimg="si2.svg"><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, while <mml:math altimg="si1.svg"><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub></mml:math> is fixed. By induction, chiral symmetry breaking is proven for any <mml:math altimg="si22.svg"><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>f</mml:mi></mml:mrow></mml:msub><mml:mo>≥</mml:mo><mml:msub><mml:mrow><mml:mi>p</mml:mi></mml:mrow><mml:mrow><mml:mi>m</mml:mi><mml:mi>i</mml:mi><mml:mi>n</mml:mi></mml:mrow></mml:msub></mml:math> in the confining regime, where <mml:math altimg="si5.svg"><mml:msub><mml:mrow><mml:mi>p</mml:mi></mml:mrow><mml:mrow><mml:mi>m</mml:mi><mml:mi>i</mml:mi><mml:mi>n</mml:mi></mml:mrow></mml:msub></mml:math> is the smallest prime factor of <mml:math altimg="si1.svg"><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub></mml:math>. The proof can be extended to <mml:math altimg="si6.svg"><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>f</mml:mi></mml:mrow></mml:msub><mml:mo linebreak="goodbreak" linebreakstyle="after"><</mml:mo><mml:msub><mml:mrow><mml:mi>p</mml:mi></mml:mrow><mml:mrow><mml:mi>m</mml:mi><mml:mi>i</mml:mi><mml:mi>n</mml:mi></mml:mrow></mml:msub></mml:math> under the additional assumption on the absence of phase transitions when quark masses are sent to infinity. Our results do not rely on assumptions on the spectrum of massless bound states other than the fact that they are color-singlet hadrons.

We investigate the energy release in the interacting magnetospheres of binary neutron stars (BNSs) with global 3D force-free electrodynamics simulations. The system dynamics depend on the inclinations χ₁ and χ₂ of the stars' magnetic dipole moments relative to their orbital angular momentum. The simplest aligned configuration (χ₁ = χ₂ = 0^∘) has no magnetic field lines connecting the two stars. Remarkably, it still develops separatrix current sheets warping around each star and a dissipative region at the interface of the two magnetospheres. A Kelvin–Helmholtz (KH)–type instability drives significant dissipation at the magnetospheric interface, generating local Alfvénic turbulence and escaping fast magnetosonic waves. Binaries with inclined magnetospheres release energy in two ways: via KH instability at the interface and via magnetic reconnection flares in the twisted flux bundles connecting the companions. Outgoing compressive waves occur in a broad range of BNS parameters, possibly developing shocks and sourcing fast radio bursts. We discuss implications for X-ray and radio precursors of BNS mergers.

Robust modeling of non-linear scales is critical for accurate cosmological inference in Stage IV surveys. For weak lensing analyses in particular, a key challenge arises from the incomplete understanding of how non-gravitational processes, such as supernovae and active galactic nuclei — collectively known as baryonic feedback — affect the matter distribution. Several existing methods for modeling baryonic feedback treat it independently from the underlying cosmology, an assumption which has been found to be inaccurate by hydrodynamical simulations. In this work, we examine the impact of this coupling between baryonic feedback and cosmology on parameter inference at LSST Y1 precision. We build mock 3×2pt data vectors using the Magneticum suite of hydrodynamical simulations, which span a wide range of cosmologies while keeping subgrid parameters fixed. We perform simulated likelihood analyses for two baryon mitigation techniques: (i) the Principal Component Analysis (PCA) method which identifies eigenmodes for capturing the effect baryonic feedback on the data vector and (ii) HMCODE2020 [1] which analytically models the modification in the matter distribution using a halo model approach. Our results show that the PCA method is more robust than HMCODE2020 with biases in Ω_m-S ₈ up to 0.3σ and 0.6σ, respectively, for large deviations from the baseline cosmology. For HMCODE2020, the bias correlates with the input cosmology while for PCA we find no such correlation.

Cyanopolyynes are among the largest and most commonly observed interstellar complex organic molecules in star-forming regions. They are believed to form primarily in the gas phase, but their formation routes are not well understood. We present a comprehensive study of the gas-phase formation network of cyanobutadiyne, HC<inline-formula><tex-math id="TM0001" notation="LaTeX">$_5$</tex-math></inline-formula>N, based on new theoretical calculations, kinetics experiments, astronomical observations, and astrochemical modelling. We performed new quantum mechanics calculations for six neutral-neutral reactions in order to derive reliable rate coefficients and product branching fractions. We also present new CRESU data on the rate coefficients of three of these reactions (C<inline-formula><tex-math id="TM0002" notation="LaTeX">$_3$</tex-math></inline-formula>N + C<inline-formula><tex-math id="TM0003" notation="LaTeX">$_2$</tex-math></inline-formula>H<inline-formula><tex-math id="TM0004" notation="LaTeX">$_2$</tex-math></inline-formula>, C<inline-formula><tex-math id="TM0005" notation="LaTeX">$_2$</tex-math></inline-formula>H + HC<inline-formula><tex-math id="TM0006" notation="LaTeX">$_3$</tex-math></inline-formula>N, CN + C<inline-formula><tex-math id="TM0007" notation="LaTeX">$_4$</tex-math></inline-formula>H<inline-formula><tex-math id="TM0008" notation="LaTeX">$_2$</tex-math></inline-formula>) obtained at temperatures as low as 24 K. In practice, six out of nine reactions currently used in astrochemical models have been updated in our reviewed network. We also report the tentative detection of the <inline-formula><tex-math id="TM0009" notation="LaTeX">$^{13}$</tex-math></inline-formula>C isotopologues of HC<inline-formula><tex-math id="TM0010" notation="LaTeX">$_5$</tex-math></inline-formula>N in the L1544 prestellar core. We derived a lower limit of <inline-formula><tex-math id="TM0011" notation="LaTeX">$^{12}$</tex-math></inline-formula>C/<inline-formula><tex-math id="TM0012" notation="LaTeX">$^{13}$</tex-math></inline-formula>C > 75 for the HC<inline-formula><tex-math id="TM0013" notation="LaTeX">$_5$</tex-math></inline-formula>N isotopologues, which does not allow to bring new constraints to the HC<inline-formula><tex-math id="TM0014" notation="LaTeX">$_5$</tex-math></inline-formula>N chemistry. Finally, we verified the impact of the revised reactions by running the GRETOBAPE astrochemical model. We found good agreement between the HC<inline-formula><tex-math id="TM0015" notation="LaTeX">$_5$</tex-math></inline-formula>N predicted and observed abundances in cold (<inline-formula><tex-math id="TM0016" notation="LaTeX">$\sim$</tex-math></inline-formula>10 K) objects, demonstrating that HC<inline-formula><tex-math id="TM0017" notation="LaTeX">$_5$</tex-math></inline-formula>N is mainly formed by neutral-neutral reactions in these environments. In warm molecular shocks, instead, the predicted abundances are a factor of ten lower with respect to observed ones. In this environment possessing an higher gas ionization fraction, we speculate that the contribution of ion-neutral reactions could be significant.

A possible way of constructing polylogarithms on Riemann surfaces of higher genera facilitates integration kernels, which can be derived from generating functions incorporating the geometry of the surface. Functional relations among polylogarithms rely on identities for those integration kernels. In this article, we derive identities for Enriquez' meromorphic generating function and investigate the implications for the associated integration kernels. The resulting identities are shown to be exhaustive and therefore reproduce all identities for Enriquez' kernels conjectured in arXiv:2407.11476 recently.

The inner Solar System is depleted in refractory carbon in comparison to the interstellar medium and the depletion likely took place in the protoplanetary disk phase of the Solar System. We study the effect of photolysis of refractory carbon in the upper layers of the protosolar disk and its interplay with dust collisional growth and vertical mixing. We make use of a 1D Monte Carlo model to simulate dust coagulation and vertical mixing. To model the FUV flux of the disk, we use a simple analytical prescription and benchmark it with data from a radiative transfer simulation. We study the effects of fragmentation and bouncing on dust distribution and the propagation of carbon depletion. We find that when bouncing is included, the size distribution is truncated at smaller sizes than fragmentation-limited size distributions but there is a loss of small grains as well. The population of small grains is reduced due to fewer fragmentation events and this reduces the effectiveness of photolysis. We find that dust collisional growth and vertical mixing increase the effectiveness of carbon depletion by efficiently replenishing carbon to the upper regions of the disk with higher FUV flux. It takes around 100-300 kyr to reach the measured carbon abundances at 1 au, depending on the strength of the turbulence in the disk. These timescales are faster than reported by previous studies. Collisional redistribution and turbulent mixing are important aspects of dust evolution that should be included when modeling dust chemistry as they can influence the efficiency of chemical processes. Photolysis, along with another process such as sublimation, most likely played a key role in refractory carbon depletion that we see around us in the inner Solar System.

We present a systematic study of one-loop quantum corrections in scalar effective field theories from a geometric viewpoint, emphasizing the role of field-space curvature and its renormalisation. By treating the scalar fields as coordinates on a Riemannian manifold, we exploit field redefinition invariance to maintain manifest coordinate independence of physical observables. Focusing on the non-linear sigma model (NLSM) and \(\phi^4\) theory, we demonstrate how loop corrections induce momentum- and scale-dependent shifts in the curvature of the field-space manifold. These corrections can be elegantly captured through the recently proposed geometry-kinematics duality, which generalizes the colour-kinematics duality in gauge theories to curved field-space backgrounds. Our results highlight a universal structure emerging in the contractions of Riemann tensors that contribute to renormalisation of the field-space curvature. In particular, we find explicit expressions and a universal structure for the running curvature and Ricci scalar in simple models, illustrating how quantum effects reshape the underlying geometry. This geometric formulation unifies a broad class of scalar EFTs, providing insight into the interplay of curvature, scattering amplitudes, and renormalisation.

This paper presents a quantitative analysis of the stellar content in the Local Group dwarf irregular galaxy NGC 6822 by comparing stellar evolution models and observations in color-magnitude diagrams (CMDs) and color-color diagrams (CC-Ds). Our analysis is based on optical ground-based g,r,i photometry, and deep archive HST photometry of two fields in the galaxy disk. We compared young, intermediate-age, and old stellar populations with isochrones from the BaSTI-IAC library and found that NGC 6822 hosts a quite metal-rich ([Fe/H] = -0.7 to -0.4) young component with an age ranging from 20 to 100 Myr. The intermediate-age population experienced a modest chemical enrichment between 4 and 8 Gyr ago while stars older than 11 Gyr have a low metal abundance ([Fe/H] ~ -1.70). We also identified the AGB clump population with a luminosity peak at i ~ 23.35 mag. Our analysis of both the CMD and the optical-NIR-MIR CC-Ds of AGB oxygen- and carbon-rich stars, using the PARSEC+COLIBRI isochrones with and without circumstellar dust, reveal that this stellar component exhibits a spread in age from 1 to 2 Gyr and in metallicity between [Fe/H]=-1.30 and -1.70. The stellar models we used reproduce very well the two distinct color sequences defined by AGB O- and C-rich stars in the various optical-NIR-MIR CC-Ds, suggesting that they are reliable diagnostics to identify and characterise intermediate-age stellar populations. However, we also find that evolutionary prescriptions in the optical i-(r-i) CMDs predict, at fixed color, systematically lower luminosities than observed AGB stars.

Star clusters can interact and merge in galactic discs, halos, or centers. We present direct N-body simulations of binary mergers of star clusters with M_⋆ = 2.7 × 10⁴ M_⊙ each, using the N-body code BIFROSTwith subsystem regularisation and post-Newtonian dynamics. We include 500 M_⊙ massive black holes (MBHs) in the progenitors to investigate their impact on remnant evolution. The MBHs form hard binaries interacting with stars and stellar black holes (BHs). A few Myr after the cluster merger, this produces sizable populations of runaway stars (~800 with v_ej ≳ 50kms^-1) and stellar BHs (~30) escaping within 100 Myr. The remnants lose ~30% of their BH population and ~3% of their stars, with ~30 stars accelerated to high velocities ≳ 300kms^-1. Comparison simulations of isolated clusters with central hard MBH binaries and cluster mergers without MBHs show that the process is driven by MBH binaries, while those with a single 1000 M_⊙ MBH in isolated or merging clusters produce fewer runaway stars at lower velocities. Low-eccentricity merger orbits yield rotating remnants (v_rot ~ 3kms^-1) , but probing the presence of MBHs via kinematics alone remains challenging. We expect the binary MBHs to merge within a Hubble time, producing observable gravitational-wave (GW) events detectable by future GW detectors such as the Einstein Telescope and LISA. The results suggest that interactions with low-mass MBH binaries formed in merging star clusters are an important additional channel for producing runaway and high-velocity stars, free-floating stellar BHs and compact objects.

Ongoing and upcoming wide-field surveys at different wavelengths will measure the distribution of galaxy clusters with unprecedented precision, demanding accurate models for the two-point correlation function (2PCF) covariance. In this work, we assess a semi-analytical framework for the cluster 2PCF covariance that employs three nuisance parameters to account for non-Poissonian shot noise, residual uncertainties in the halo bias model, and subleading noise terms. We calibrate these parameters on a suite of fast approximate simulations generated by PINOCCHIO as well as full $N$-body simulations from OpenGADGET3. We demonstrate that PINOCCHIO can reproduce the 2PCF covariance measured in OpenGADGET3 at the few percent level, provided the mass functions are carefully rescaled. Resolution tests confirm that high particle counts are necessary to capture shot-noise corrections, especially at high redshifts. We perform the parameter calibration across multiple cosmological models, showing that one of the nuisance parameters, the non-Poissonian shot-noise correction $\alpha$, depends mildly on the amplitude of matter fluctuations $\sigma_8$. In contrast, the remaining two parameters, $\beta$ controlling the bias correction and $\gamma$ controlling the secondary shot-noise correction, exhibit more significant variation with redshift and halo mass. Overall, our results underscore the importance of calibrating covariance models on realistic mock catalogs that replicate the selection function of forthcoming surveys and highlight that approximate methods, when properly tuned, can effectively complement full $N$-body simulations for precision cluster cosmology.

Cosmic shear, galaxy clustering, and the abundance of massive halos each probe the large-scale structure of the Universe in complementary ways. We present cosmological constraints from the joint analysis of the three probes, building on the latest analyses of the lensing-informed abundance of clusters identified by the South Pole Telescope (SPT) and of the auto- and cross-correlation of galaxy position and weak lensing measurements (<inline-formula><mml:math display="inline"><mml:mn>3</mml:mn><mml:mo>×</mml:mo><mml:mn>2</mml:mn><mml:mi>pt</mml:mi></mml:math></inline-formula>) in the Dark Energy Survey (DES). We consider the cosmological correlation between the different tracers and we account for the systematic uncertainties that are shared between the large-scale lensing correlation functions and the small-scale lensing-based cluster mass calibration. Marginalized over the remaining <inline-formula><mml:math display="inline"><mml:mi mathvariant="normal">Λ</mml:mi></mml:math></inline-formula> cold dark matter (<inline-formula><mml:math display="inline"><mml:mi mathvariant="normal">Λ</mml:mi><mml:mi>CDM</mml:mi></mml:math></inline-formula>) parameters (including the sum of neutrino masses) and 52 astrophysical modeling parameters, we measure <inline-formula><mml:math display="inline"><mml:msub><mml:mi mathvariant="normal">Ω</mml:mi><mml:mi mathvariant="normal">m</mml:mi></mml:msub><mml:mo>=</mml:mo><mml:mn>0.300</mml:mn><mml:mo>±</mml:mo><mml:mn>0.017</mml:mn></mml:math></inline-formula> and <inline-formula><mml:math display="inline"><mml:msub><mml:mi>σ</mml:mi><mml:mn>8</mml:mn></mml:msub><mml:mo>=</mml:mo><mml:mn>0.797</mml:mn><mml:mo>±</mml:mo><mml:mn>0.026</mml:mn></mml:math></inline-formula>. Compared to constraints from Planck primary cosmic microwave background (CMB) anisotropies, our constraints are only 15% wider with a probability to exceed of 0.22 (<inline-formula><mml:math display="inline"><mml:mn>1.2</mml:mn><mml:mi>σ</mml:mi></mml:math></inline-formula>) for the two-parameter difference. We further obtain <inline-formula><mml:math display="inline"><mml:msub><mml:mi>S</mml:mi><mml:mn>8</mml:mn></mml:msub><mml:mo>≡</mml:mo><mml:msub><mml:mi>σ</mml:mi><mml:mn>8</mml:mn></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mi mathvariant="normal">Ω</mml:mi><mml:mi mathvariant="normal">m</mml:mi></mml:msub><mml:mo>/</mml:mo><mml:mn>0.3</mml:mn><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mn>0.5</mml:mn></mml:msup><mml:mo>=</mml:mo><mml:mn>0.796</mml:mn><mml:mo>±</mml:mo><mml:mn>0.013</mml:mn></mml:math></inline-formula> which is lower than the Planck measurement at the <inline-formula><mml:math display="inline"><mml:mn>1.6</mml:mn><mml:mi>σ</mml:mi></mml:math></inline-formula> level. The combined SPT cluster, DES <inline-formula><mml:math display="inline"><mml:mn>3</mml:mn><mml:mo>×</mml:mo><mml:mn>2</mml:mn><mml:mi>pt</mml:mi></mml:math></inline-formula>, and Planck datasets mildly prefer a nonzero positive neutrino mass, with a 95% upper limit <inline-formula><mml:math display="inline"><mml:mo>∑</mml:mo><mml:msub><mml:mi>m</mml:mi><mml:mi>ν</mml:mi></mml:msub><mml:mo><</mml:mo><mml:mn>0.25</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>eV</mml:mi></mml:math></inline-formula> on the sum of neutrino masses. Assuming a <inline-formula><mml:math display="inline"><mml:mi>w</mml:mi><mml:mi>CDM</mml:mi></mml:math></inline-formula> model, we constrain the dark energy equation of state parameter <inline-formula><mml:math display="inline"><mml:mi>w</mml:mi><mml:mo>=</mml:mo><mml:mo>-</mml:mo><mml:mn>1.1</mml:mn><mml:msubsup><mml:mn>5</mml:mn><mml:mrow><mml:mo>-</mml:mo><mml:mn>0.17</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo><mml:mn>0.23</mml:mn></mml:mrow></mml:msubsup></mml:math></inline-formula> and when combining with Planck primary CMB anisotropies, we recover <inline-formula><mml:math display="inline"><mml:mi>w</mml:mi><mml:mo>=</mml:mo><mml:mo>-</mml:mo><mml:mn>1.2</mml:mn><mml:msubsup><mml:mn>0</mml:mn><mml:mrow><mml:mo>-</mml:mo><mml:mn>0.09</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo><mml:mn>0.15</mml:mn></mml:mrow></mml:msubsup></mml:math></inline-formula>, a <inline-formula><mml:math display="inline"><mml:mn>1.7</mml:mn><mml:mi>σ</mml:mi></mml:math></inline-formula> difference with a cosmological constant. The precision of our results highlights the benefits of multiwavelength multiprobe cosmology and our analysis paves the way for upcoming joint analyses of next-generation datasets.

We investigate cosmological correlators for conformally coupled ϕ⁴ theory in four-dimensional de Sitter space. These in-in correlators differ from scattering amplitudes for massless particles in flat space due to the spacelike structure of future infinity in de Sitter. They also require a regularization which preserves de Sitter-invariance, which makes the flat space limit subtle to define at loop-level. Nevertheless we find that up to two loops, the in-in correlators are structurally simpler than the wave function and have the same transcendentality as flat space amplitudes. Moreover, we show that their loop integrands can be recast in terms of flat space integrands and can be derived from a novel recursion relation.

Neutron supermirrors (SMs) are a crucial part of many scattering and particle physics experiments. So far, Ni(Mo)/Ti SMs have been used in experiments that require to transport a polarized neutron beam due to their lower saturation magnetization compared to Ni/Ti SMs. However, next generation $\beta$ decay experiments require SMs that depolarize below $10^{-4}$ per reflection to reach their targeted precision. The depolarization of a polarized neutron beam due to reflection from Ni(Mo)/Ti SMs has not yet been measured to that precision. Recently developed Cu/Ti SMs with a very low saturation magnetization compared to Ni(Mo)/Ti may serve as an alternative. In this paper, we test the performance of both mirrors. At a first stage, we present four-states polarized neutron reflectivity (PNR) curves of Ni(Mo) and Cu monolayers measured at the neutron reflectometer SuperADAM and perform a full polarization analysis, showing a difference between the magnetic scattering length density (mSLD) of both materials, with Cu having a lower mSLD than Ni(Mo). These results are corroborated with the full polarization analysis of four-states PNR curves of $m=2$ Ni(Mo)/Ti and Cu/Ti SMs. In a second stage, we measured the depolarization ($D$) that a polarized neutron beam suffers after reflection from the same Ni(Mo)/Ti and Cu/Ti SMs by using the Opaque Test Bench setup. We find upper limits for the depolarization of $D_\text{Cu/Ti(4N5)}<7.6\times 10^{-5}$, $D_\text{Ni(Mo)/Ti}<8.5\times 10^{-5}$, and $D_\text{Cu/Ti(2N6)}<6.0\times 10^{-5}$ at the $1\sigma$ confidence level, where (4N5) corresponds to a Ti purity of $99.995\%$ and (2N6) to $99.6\%$. The uncertainties are statistical. These results show that all three SMs are suitable for being used in next generation $\beta$ decay experiments. We found no noticeable dependence of $D$ on the $q$ value or the magnetizing field, in which the samples were placed.

Motivated by JWST observations of dense, clumpy and clustered high redshift star formation, we simulate the hierarchical assembly of nine $M_{\mathrm{cl}}=10^6 M_\odot$ star clusters using the BIFROST N-body code. Our low metallicity models ($0.01Z_\odot$) 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 $M_\mathrm{\bullet}\sim6200 M_\odot$, stellar multiplicity boosting the IMBH masses by a factor of $2$--$3$. The IMBHs tidally disrupt (TDE) $\sim50$ stars in $10$ Myr with peak TDE rates of $\Gamma\sim10^{-5}$ yr$^{-1}$ per cluster. These IMBHs are natural seeds for supermassive black holes (SMBHs) and the hierarchical assembly frequently leads to $>2$ SMBH seeds per cluster and their rapid mergers ($t<10$ Myr). We propose that a gravitational wave (GW) driven merger of IMBHs with $1000 M_\odot \lesssim M_\bullet \lesssim 10000 M_\odot$ with comparable masses is a characteristic GW fingerprint of SMBH seed formation at redshifts $z>10$, 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.

[Abridged] Cassiopeia A (Cas A) provides a unique opportunity to study supernova (SN) dynamics and interactions with the circumstellar medium (CSM). Recent JWST observations revealed the "Green Monster" (GM), a structure with a likely CSM origin. We investigate its pockmarked morphology, characterized by circular holes and rings, by examining the role of small-scale ejecta structures interacting with a dense circumstellar shell. We adopted a neutrino-driven SN model to trace the evolution of its explosion from core collapse to the age of the Cas A remnant using high-resolution 3D magnetohydrodynamic simulations. Besides other processes, the simulations include self-consistent calculations of radiative losses, accounting for deviations from electron-proton temperature equilibration and ionization equilibrium, as well as the ejecta composition derived from the SN. The GM's morphology is reproduced by dense ejecta clumps and fingers interacting with an asymmetric, forward-shocked circumstellar shell. The clumps and fingers form by hydrodynamic instabilities growing at the interface between SN ejecta and shocked CSM. Radiative cooling accounting for effects of non-equilibrium of ionization enhances the ejecta fragmentation, forming dense knots and thin filamentary structures that penetrate the shell, producing a network of holes and rings with properties similar to those observed. The origin of the holes and rings in the GM can be attributed to the interaction of ejecta with a shocked circumstellar shell. By constraining the timing of this interaction and analyzing the properties of these structures, we provide a distinction of this scenario from an alternative hypothesis, which attributes these features to fast-moving ejecta knots penetrating the shell ahead of the forward shock.

Aims. We use Gaia DR3 astrometry and photometry to analyze the spatial distribution of the young stellar populations and stellar clusters and to search for new OB star candidates in the Carina Nebula complex and the full extent (∼5°, corresponding to ∼200 pc) of the Car OB1 association. Methods. We first performed a new census of high-mass stars in Car OB1 and compiled a comprehensive catalog of 517 stars with known spectral types (128 O-type, WR, and supergiant stars, and 389 B-type stars) that have Gaia DR3 parallaxes consistent with membership in the association. We applied the clustering algorithm DBSCAN on the Gaia DR3 data of the region to find stellar clusters, determine their distances and kinematics, and estimate ages. We also used Gaia astrometry and the additional astrophysical_parameters table to perform a spatially unbiased search for further high-mass members of Car OB1 over the full area of the association. Results. Our DBSCAN analysis finds 15 stellar clusters and groups in Car OB1, four of which were not known before. Most clusters (80%) show signs of expansion or contraction, four of them with a ≥2σ significance. We find a global expansion of the Car OB1 association with a velocity of v_out = 5.25 ± 0.02 km s^‑1. A kinematic traceback of the high-mass stars shows that the spatial extent of the association was at a minimum 3–4 Myr ago. Using astrophysical parameters by Gaia DR3, we identified 15 new O-type and 589 new B-type star candidates in Car OB1. The majority (≳54%) of the high-mass stars constitute a non-clustered distributed stellar population. Based on our sample of high-mass stars, we estimate a total stellar population of at least ∼8 × 10⁴ stars in Car OB1. Conclusions. Our study is the first systematic astrometric analysis that covers the full spatial extent of the Car OB1 association, and it therefore substantially increases the knowledge of the distributed stellar population and spatial evolution of the entire association. Our results suggest suggests Car OB1 to be the most massive known star-forming complex in our Galaxy.

Radiation is crucial not only for observing astrophysical objects, but also for transporting energy and momentum. However, accurate on-the-fly radiation transport in astrophysical simulations is challenging and computationally expensive. Here we introduce AREPO-IDORT (Implicit Discrete Ordinates Radiation Transport), a scheme coupled to the explicit magnetohydrodynamic (MHD) solver in the 3D moving-mesh code AREPO. The discrete ordinates scheme means we directly solve for the specific intensities along discrete directions. We solve the time-dependent relativistic radiation transport equation via an implicit Jacobi-like iterative finite-volume solver, which overcomes the small radiation time-steps needed by explicit methods. Compared to commonly-used moment-based methods, e.g. flux-limited diffusion or M1 closure, this scheme has the advantage of correctly capturing the direction of radiation in both optically-thick and thin regions. It is based on the scheme by Jiang 2021 for the adaptive mesh refinement code ATHENA++, but we generalize the scheme to support (1) an unstructured moving-mesh, (2) local time-stepping, and (3) general equations of state. We show various test problems that commonly-used moment-based methods fail to reproduce accurately. To apply the scheme to a real astrophysics problem, we show the first global 3D radiation hydrodynamic simulation of the entire convective envelope of a red supergiant star. (abridged) For this problem, the radiation module only takes less than half of the total computational cost. Our current scheme assumes grey radiation, is first-order accurate in both time and space (abridged). We expect our scheme will enable more accurate multi-scale radiation MHD simulations involving supersonic bulk motions, ranging from planet formation in protoplanetary disks, stars and associated transients, to accretion flows near black holes.

Context. Brown dwarfs are the bridge between low-mass stars and giant planets. One way of shedding light on their dominant formation mechanism is to study them at the earliest stages of their evolution, when they are deeply embedded in their parental clouds. Several works have identified pre- and proto-brown dwarf candidates using different observational approaches. Aims. The aim of this work is to create a database of all the objects classified as very young substellar candidates in the literature in order to study them homogeneously. Methods. We gathered all the information about very young substellar candidates available in the literature until 2020. We retrieved their published photometry from the optical to the centimetre regime, and we wrote our own codes to derive their bolometric temperatures and luminosities, and their internal luminosities. We also populated the database with other parameters extracted from the literature, such as the envelope masses, their detection in some molecular species, and the presence of outflows. Results. The result of our search is the SUbstellar CANdidates at the Earliest Stages (SUCANES) database, containing 174 objects classified as potential very young substellar candidates in the literature. We present an analysis of the main properties of the retrieved objects. Since we updated the distances to several star forming regions, we were able to reject some candidates based on their internal luminosities. We also discuss the derived physical parameters and envelope masses for the best substellar candidates isolated in SUCANES. As an example of a scientific exploitation of this database, we present a feasibility study for the detection of radio jets with upcoming facilities: the next generation Very Large Array and the Square Kilometer Array interferometers. The SUCANES database is accessible through a graphical user interface, and it is open to any potential user.

We show how a method to construct canonical differential equations for multi-loop Feynman integrals recently introduced by some of the authors can be extended to cases where the associated geometry is of Calabi-Yau type and even beyond. This can be achieved by supplementing the method with information from the mixed Hodge structure of the underlying geometry. We apply these ideas to specific classes of integrals whose associated geometry is a one-parameter family of Calabi-Yau varieties, and we argue that the method can always be successfully applied to those cases. Moreover, we perform an in-depth study of the properties of the resulting canonical differential equations. In particular, we show that the resulting canonical basis is equivalent to the one obtained by an alternative method recently introduced in the literature. We apply our method to non-trivial and cutting-edge examples of Feynman integrals necessary for gravitational wave scattering, further showcasing its power and flexibility.

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

Aims. We introduce the SISSI (Supernovae In a Stratified, Shearing Interstellar medium) simulation suite, which aims to enable a more comprehensive understanding of supernova remnants (SNRs) evolving in a complex interstellar medium (ISM) structured under the influence of galactic rotation, gravity and turbulence. Methods. We utilize zoom-in simulations of 30 SNRs expanding in the ISM of a simulated isolated disk galaxy. The ISM of the galaxy is resolved down to a maximum resolution of $\sim 12\,\text{pc}$, while we achieve a zoomed-in resolution of $\sim 0.18\, \text{pc}$ in the vicinity of the explosion sources. We compute the time-evolution of the SNRs' geometry and compare it to the observed geometry of the Local Bubble. Results. During the early stages of evolution, SNRs are well described by existing analytical models. On longer timescales, starting at about a percent of the orbital timescale, they depart from spherical symmetry and become increasingly prolate or oblate. The timescale for the departure from spherical symmetry is shorter than the expectation from a simple model for the deformation by galactic shear, suggesting that galactic shear alone cannot explain these differences. Yet, the alignment of the minor- and major axis of the SNRs is in line with expectations from said model, indicating that the deformation might have a shear-related origin. A comparison with the geometry of the Local Bubble reveals that it might be slightly younger than previously believed, but otherwise has a standard morphology for a SNR of its age and size. Conclusions. Studying the geometry of SNRs can reveal valuable insights about the complex interactions shaping their dynamical evolution. Future studies targeting the geometry of Galactic SNRs may use this insight to obtain a clearer picture of the processes shaping the Galactic ISM.

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

The strongly lensed Supernova (SN) Encore at a redshift of $z = 1.949$, discovered behind the galaxy cluster MACS J0138$-$2155 at $z=0.336$, provides a rare opportunity for time-delay cosmography and studies of the SN host galaxy, where previously another SN, called SN Requiem, had appeared. To enable these studies, we combine new James Webb Space Telescope (JWST) imaging, archival Hubble Space Telescope (HST) imaging, and new Very Large Telescope (VLT) spectroscopic data to construct state-of-the-art lens mass models that are composed of cluster dark-matter (DM) halos and galaxies. We determine the photometric and structural parameters of the galaxies across six JWST and five HST filters. We use the color-magnitude and color-color relations of spectroscopically-confirmed cluster members to select additional cluster members, identifying a total of 84 galaxies belonging to the galaxy cluster. We construct seven different mass models using a variety of DM halo mass profiles, and explore both multi-plane and approximate single-plane lens models. As constraints, we use the observed positions of 23 multiple images from eight multiply lensed sources at four distinct spectroscopic redshifts. In addition, we use stellar velocity dispersion measurements to obtain priors on the galaxy mass distributions. We find that six of the seven models fit well to the observed image positions. Mass models with cored-isothermal DM profiles fit well to the observations, whereas the mass model with a Navarro-Frenk-White cluster DM profile has an image-position $\chi^2$ value that is four times higher. We build our ultimate model by combining four multi-lens-plane mass models and predict the image positions and magnifications of SN Encore and SN Requiem. Our work lays the foundation for building state-of-the-art mass models of the cluster for future cosmological analysis and SN host galaxy studies.

Precision spectroscopy of the electron spectrum of the tritium $\beta$-decay near the kinematic endpoint is a direct method to determine the effective electron antineutrino mass. The KArlsruhe TRItium Neutrino (KATRIN) experiment aims to determine this quantity with a sensitivity of better than 0.3$\,$eV (90$\,$% C.L.). An inhomogeneous electric potential in the tritium source of KATRIN can lead to distortions of the $\beta$-spectrum, which directly impact the neutrino-mass observable. This effect can be quantified through precision spectroscopy of the conversion-electrons of co-circulated metastable $^{83m}$Kr. Therefore, dedicated, several-weeks long measurement campaigns have been performed within the KATRIN data taking schedule. In this work, we infer the tritium source potential observables from these measurements, and present their implications for the neutrino-mass determination.

Understanding the coevolution of supermassive black holes and their host galaxies requires tracing their growth over time. Mass measurements of distant black holes have been limited to active nuclei and commonly rely on spatially unresolved observations, leading to large uncertainties. Accurate masses can be determined by resolving the kinematics of stars within the sphere of influence, which has heretofore been possible only in the local universe. Using JWST, we have measured the mass $M_{\bullet}=6.0^{+2.1}_{-1.7}\times10^9$ ${\rm M}_{\odot}$ of an inactive black hole in a gravitationally lensed quiescent galaxy at redshift $z=1.95$, along with detailed host properties. Comparisons to local galaxies suggest that the correlation between $M_{\bullet}$ and bulge mass has evolved substantially, whereas the correlation with stellar velocity dispersion may have been in place for 10 Gyr.

A puzzling population of extremely massive quiescent galaxies at redshifts beyond z = 3 has recently been revealed by JWST and the Atacama Large Millimeter/submillimeter Array, some of them with stellar ages that show their quenching times to be as high as z = 6, while their stellar masses are already above 5 × 10¹⁰ M _⊙. These extremely massive yet quenched galaxies challenge our understanding of galaxy formation at the earliest stages. Using the hydrodynamical cosmological simulation suite Magneticum Pathfinder, we show that such massive quenched galaxies at high redshifts can be successfully reproduced with similar number densities as observed. The stellar masses, sizes, formation redshifts, and star formation histories of the simulated quenched galaxies match those determined with JWST. Following these quenched galaxies at z = 3.4 forward in time, we find 20% to be accreted onto a more massive structure by z = 2, and from the remaining 80% about 30% rejuvenate up to z = 2, another 30% stay quenched, and the remaining 40% rejuvenate on a very low level of star formation. Stars formed through rejuvenation are mostly formed on the outer regions of the galaxies, not in the centers. Furthermore, we demonstrate that the massive quenched galaxies do not reside in the most massive nodes of the cosmic web, but rather live in side nodes of approximately Milky Way halo mass. Even at z = 0, only about 10% end up in small-mass galaxy clusters, while most of the quenched galaxies at z = 3.4 end up in group-mass halos, with about 20% actually not even reaching 10¹³ M _⊙ in halo mass.

Our picture of galaxy evolution currently assumes that galaxies spend their life on the star formation main sequence until they may eventually be quenched. However, recent observations show indications that the full picture might be more complicated. We reveal how the star formation rates of galaxies evolve, possible causes and imprints of different evolution scenarios on galactic features. We follow the evolution of central galaxies in the highest-resolution box of the Magneticum Pathfinder cosmological hydrodynamical simulations and classify their evolution scenarios with respect to the star formation main sequence. We find that a major fraction of the galaxies undergoes long-term cycles of quenching and rejuvenation on Gyr timescales. This expands the framework of galaxy evolution from a secular evolution to a sequence of multiple active and passive phases. Only 14% of field galaxies on the star formation main sequence at z~0 actually evolved along the scaling relation, while the bulk of star forming galaxies in the local universe have undergone cycles of quenching and rejuvenation. In this work we describe the statistics of these galaxy evolution modes and how this impacts their stellar masses, ages and metallicities today. Galaxies with rejuvenation cycles can be distinguished well from main-sequence-evolved galaxies in their features at z~0. We further explore possible explanations and find that the geometry of gas accretion at the halo outskirts shows a strong correlation with the star formation rate evolution, while the density parameter as a tracer of environment shows no significant correlation. A derivation of star formation rates from gas accretion with simple assumptions only works reasonably well in the high-redshift universe where accreted gas gets quickly converted into stars.

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

By employing the potential non-relativistic quantum chromodynamics (pNRQCD) effective field theory within an open quantum system framework, we derive a Lindblad equation governing the evolution of the heavy-quarkonium reduced density matrix, accurate to next-to-leading order (NLO) in the ratio of the state's binding energy to the medium's temperature [1]. The derived NLO Lindblad equation provides a more reliable description of heavy-quarkonium evolution in the quark-gluon plasma at low temperatures compared to the leading-order truncation. For phenomenological applications, we numerically solve this equation using the quantum trajectories algorithm. By averaging over Monte Carlo-sampled quantum jumps, we obtain solutions without truncation in the angular momentum quantum number of the considered states. Our analysis highlights the importance of quantum jumps in the nonequilibrium evolution of bottomonium states within the quark-gluon plasma [2]. Additionally, we demonstrate that the quantum regeneration of singlet states from octet configurations is essential to explain experimental observations of bottomonium suppression. The heavy-quarkonium transport coefficients used in our study align with recent lattice QCD determinations.

Cosmic birefringence (CB) is the rotation of the photons' linear polarisation plane during propagation. Such an effect is a tracer of parity-violating extensions of standard electromagnetism and would probe the existence of a new cosmological field acting as dark matter or dark energy. It has become customary to employ cosmic microwave background (CMB) polarised data to probe such a phenomenon. Recent analyses on Planck and WMAP data provide a hint of detection of the isotropic CB angle with an amplitude of around $0.3^\circ$ at the level of $2.4$ to $3.6\sigma$. In this work, we explore the LiteBIRD capabilities in constraining such an effect, accounting for the impact of the more relevant systematic effects, namely foreground emission and instrumental polarisation angles. We build five semi-independent pipelines and test these against four different simulation sets with increasing complexity in terms of non-idealities. All the pipelines are shown to be robust and capable of returning the expected values of the CB angle within statistical fluctuations for all the cases considered. We find that the uncertainties in the CB estimates increase with more complex simulations. However, the trend is less pronounced for pipelines that account for the instrumental polarisation angles. For the most complex case analysed, we find that LiteBIRD will be able to detect a CB angle of $0.3^\circ$ with a statistical significance ranging from $5$ to $13 \, \sigma$, depending on the pipeline employed, where the latter uncertainty corresponds to a total error budget of the order of $0.02^\circ$.

Aims. We investigate the role of cosmic ray (CR) halos in shaping the properties of starburst-driven galactic outflows. Methods. We develop a microphysical model for galactic outflows driven by a continuous central feedback source, incorporating a simplified treatment of CRs. The model parameters are linked to the effective properties of a starburst. By analyzing its asymptotic behavior, we derive a criterion for launching starburst-driven galactic outflows and determine the corresponding outflow velocities. Results. We find that in the absence of CRs, galactic outflows can only be launched if the star-formation rate (SFR) surface density exceeds a critical threshold proportional to the dynamical equilibrium pressure. In contrast, CRs can always drive slow outflows. CRs dominate in systems with SFR surface densities below the critical threshold but become negligible in highly star-forming systems. However, in older systems with established CR halos, the CR contribution to outflows diminishes once the outflow reaches the galactic scale height, rendering CRs ineffective in sustaining outflows in such systems. Conclusions. Over cosmic time, galaxies accumulate relic CRs in their halos, providing additional non-thermal pressure support that suppresses low-velocity CR-driven outflows. We predict that such low-velocity outflows are expected only in young systems that have not yet built up significant CR halos. In contrast, fast outflows in starburst galaxies, where the SFR surface density exceeds the critical threshold, are primarily driven by momentum injection and remain largely unaffected by CR halos.

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. We explore under which conditions neutron-capture processes can occur in late helium core flashes, i.e. those occurring in the cores of stripped red-giant stars. We compute evolutionary models through the helium core flash and the subsequent hydrogen ingestion episode in stripped red giant stars. Stellar structure models are then used in post-processing to compute the detailed evolution of neutron-capture elements. We find that for metallicities of $10^{-3}$ and below, neutron densities can be as high as $10^{15}\,$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. 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. Intermediate neutron capture processes can occur in the He-core flash experienced by the cores of some stripped red giants, and 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 latest generation of cosmic-ray direct detection experiments is providing a wealth of high-precision data, stimulating a very rich and active debate in the community on the related strong discovery and constraining potentials on many topics, namely dark matter nature, and the sources, acceleration, and transport of Galactic cosmic rays. However, interpretation of these data is strongly limited by the uncertainties on nuclear and hadronic cross-sections. This contribution is one of the outcomes of the \textit{Cross-Section for Cosmic Rays at CERN} workshop series, that built synergies between experimentalists and theoreticians from the astroparticle, particle physics, and nuclear physics communities. A few successful and illustrative examples of CERN experiments' efforts to provide missing measurements on cross-sections are presented. In the context of growing cross-section needs from ongoing, but also planned, cosmic-ray experiments, a road map for the future is highlighted, including overlapping or complementary cross-section needs from applied topics (e.g., space radiation protection and hadrontherapy).

Data from particle physics experiments are unique and are often the result of a very large investment of resources. Given the potential scientific impact of these data, which goes far beyond the immediate priorities of the experimental collaborations that obtain them, it is imperative that the collaborations and the wider particle physics community publish and preserve sufficient information to ensure that this impact can be realised, now and into the future. The information to be published and preserved includes the algorithms, statistical information, simulations and the recorded data. This publication and preservation requires significant resources, and should be a strategic priority with commensurate planning and resource allocation from the earliest stages of future facilities and experiments.

[abridged] AGN feedback is a crucial ingredient for understanding galaxy evolution. However, a complete quantitative time-dependent framework, including the dependence of such feedback on AGN, host galaxy, and host halo properties, is yet to be developed. Using the complete sample of 682 radio AGN from the LOFAR-eFEDS survey ($z0.4$), we derive the average jet power of massive galaxies and its variation as a function of stellar mass ($M_*$), halo mass ($M_h$) and radio morphology. We compare the incidence distributions of compact and complex radio AGN as a function of specific black hole kinetic power, $λ_{\rm Jet}$, and synthesise, for the first time, the radio luminosity function (RLF) by $M_*$ and radio morphology. Our RLF and derived total radio AGN kinetic luminosity density, $\log Ω_{\rm kin}/[\rm {W~Mpc^{-3}}]=32.15_{-0.34}^{+0.18}$, align with previous work. We find that kinetic feedback from radio AGN dominates over any plausible inventory of radiatively-driven feedback for galaxies with $\log M_*/M_\odot > 10.6$. More specifically, it is the compact radio AGN which dominate this global kinetic energy budget for all but the most massive galaxies ($10.6 < \log M_*/M_{\odot} < 11.5$). Subsequently, we compare the average injected jet energy against the galaxy and halo binding energy, and against the total thermal energy of the host gas within halos. We find that radio AGN cannot fully unbind their host galaxies nor host halos. However, they have enough energy to impact the global thermodynamical heating and cooling balance in small halos and significantly contribute to offsetting local cooling flows in even the most massive clusters cores. Overall, our findings provide important insights on jet powering, accretion processes and black hole-galaxy coevolution via AGN feedback, as well as a clear observational benchmark to calibrate AGN feedback simulations.

The measurement of the bound-state $β$ decay of $^{205}\mathrm{Tl}^{81+}$ at the Experimental Storage Ring at GSI, Darmstadt, has recently been reported with substantial impact on the use of $^{205}\mathrm{Pb}$ as an early Solar System chronometer and the low-energy measurement of the solar neutrino spectrum via the LOREX project. Due to the technical challenges in producing a high-purity $^{205}\mathrm{Tl}^{81+}$ secondary beam, a robust statistical method needed to be developed to estimate the variation in the contaminant $^{205}\mathrm{Pb}^{81+}$ produced during the fragmentation reaction. Here we show that Bayesian and Monte Carlo methods produced comparable estimates for the contaminant variation, each with unique advantages and challenges given the complex statistical problems for this experiment. We recommend the adoption of such methods in future experiments that exhibit unknown statistical fluctuations.

Cosmic Voids are a promising probe of cosmology for spectroscopic galaxy surveys due to their unique response to cosmological parameters. Their combination with other probes promises to break parameter degeneracies. Due to simplifying assumptions, analytical models for void statistics are only representative of a subset of the full void population. We present a set of neural-based emulators for void summary statistics of watershed voids, which retain more information about the full void population than simplified analytical models. We build emulators for the void size function and void density profiles traced by the halo number density using the Quijote suite of simulations for a broad range of the $\Lambda\mathrm{CDM}$ parameter space. The emulators replace the computation of these statistics from computationally expensive cosmological simulations. We demonstrate the cosmological constraining power of voids using our emulators, which offer orders-of-magnitude acceleration in parameter estimation, capture more cosmological information compared to analytic models, and produce more realistic posteriors compared to Fisher forecasts. We find that the parameters $\Omega_m$ and $\sigma_8$ in this Quijote setup can be recovered to $14.4\%$ and $8.4\%$ accuracy respectively using void density profiles; including the additional information in the void size function improves the accuracy on $\sigma_8$ to $6.8\%$. We demonstrate the robustness of our approach to two important variables in the underlying simulations, the resolution, and the inclusion of baryons. We find that our pipeline is robust to variations in resolution, and we show that the posteriors derived from the emulated void statistics are unaffected by the inclusion of baryons with the Magneticum hydrodynamic simulations. This opens up the possibility of a baryon-independent probe of the large-scale structure.

Collective oscillations in dense neutrino gases (flavor waves) are notable for their instabilities that cause fast flavor conversion. We develop a quantum theory of interacting neutrinos and flavor wave quanta, which are analogous to plasmons, but also carry flavor. The emission or absorption of such flavor plasmons $\psi$, or flavomons, changes the neutrino flavor. When an angular crossing occurs, the process $\nu_\mu\to\nu_e+\psi$ is more rapid than its inverse along the direction of the crossing, triggering stimulated $\psi$ emission and fast instability. Calculating the rate via Feynman diagrams matches the fast instability growth rate. Our novel $\nu$ and $\psi$ kinetic equations, corresponding to quasi-linear theory, describe instability evolution without resolving the small scales of the flavomon wavelength, potentially overcoming the main challenge of fast flavor evolution.

Finding the best parametrization for cosmological models in the absence of first-principle theories is an open question. We propose a data-driven parametrization of cosmological models given by the disentangled 'latent' representation of a variational autoencoder (VAE) trained to compress cosmic microwave background (CMB) temperature power spectra. We consider a broad range of $\Lambda$CDM and beyond-$\Lambda$CDM cosmologies with an additional early dark energy (EDE) component. We show that these spectra can be compressed into 5 ($\Lambda$CDM) or 8 (EDE) independent latent parameters, as expected when using temperature power spectra alone, and which reconstruct spectra at an accuracy well within the Planck errors. These latent parameters have a physical interpretation in terms of well-known features of the CMB temperature spectrum: these include the position, height and even-odd modulation of the acoustic peaks, as well as the gravitational lensing effect. The VAE also discovers one latent parameter which entirely isolates the EDE effects from those related to $\Lambda$CDM parameters, thus revealing a previously unknown degree of freedom in the CMB temperature power spectrum. We further showcase how to place constraints on the latent parameters using Planck data as typically done for cosmological parameters, obtaining latent values consistent with previous $\Lambda$CDM and EDE cosmological constraints. Our work demonstrates the potential of a data-driven reformulation of current beyond-$\Lambda$CDM phenomenological models into the independent degrees of freedom to which the data observables are sensitive.

Ultra-hot Jupiters, an extreme class of planets not found in our solar system, provide a unique window into atmospheric processes. The extreme temperature contrasts between their day- and night-sides pose a fundamental climate puzzle: how is energy distributed? To address this, we must observe the 3D structure of these atmospheres, particularly their vertical circulation patterns, which can serve as a testbed for advanced Global Circulation Models (GCM) [e.g. 1]. Here, we show a dramatic shift in atmospheric circulation in an ultra-hot Jupiter: a unilateral flow from the hot star-facing side to the cooler space-facing side of the planet sits below an equatorial super-rotational jet stream. By resolving the vertical structure of atmospheric dynamics, we move beyond integrated global snapshots of the atmosphere, enabling more accurate identification of flow patterns and allowing for a more nuanced comparison to models. Global circulation models based on first principles struggle to replicate the observed circulation pattern [3], underscoring a critical gap between theoretical understanding of atmospheric flows and observational evidence. This work serves as a testbed to develop more comprehensive models applicable beyond our Solar System as we prepare for the next generation of giant telescopes.

We use the effective field theory approach to systematically study the dynamics of classical and quantum systems in an oscillating magnetic field. We find that the fast field oscillations give rise to an effective interaction which is able to confine charged particles as well as neutral particles with a spin magnetic moment. The effect is reminiscent of the renown dynamical stabilization of charges by the oscillating electric field and provides a foundation for a new class of magnetic traps. The properties characteristic to the dynamical magnetic confinement are reviewed.

Transit spectroscopy usually relies on the integration of one or several transits to achieve the S/N necessary to resolve spectral features. Consequently, high-S/N observations of exoplanet atmospheres are essential for disentangling the complex chemistry and dynamics beyond global trends. In this study, we combined two partial 4-UT transits of the ultrahot Jupiter WASP-121 b, observed with the ESPRESSO at the VLT in order to revisit its titanium chemistry. Through cross-correlation analysis, we achieved detections of H I, Li I, Na I, K I, Mg I, Ca I, Ti I, V I, Cr I, Mn I, Fe I, Fe II, Co I, Ni I, Ba II, Sr I, and Sr II. Additionally, narrow-band spectroscopy allowed us to resolve strong single lines, resulting in significant detections of H$\alpha$, H$\beta$, H$\gamma$, Li I, Na I, K I, Mg I, Ca II, Sr I, Sr II, and Mn I. Our most notable finding is the high-significance detection of Ti I ($\sim$ 5$\sigma$ per spectrum, and $\sim$ 19$\sigma$ stacked in the planetary rest frame). Comparison with atmospheric models reveals that Ti I is indeed depleted compared to V I. We also resolve the planetary velocity traces of both Ti I and V I, with Ti I exhibiting a significant blueshift toward the end of the transit. This suggests that Ti I primarily originates from low-latitude regions within the super-rotating jet observed in WASP-121 b. Our observations suggest limited mixing between the equatorial jet and the mid-latitudes, in contrast with model predictions from GCMs. We also report the non-detection of TiO, which we attribute to inaccuracies in the line list that could hinder its detection, even if present. Thus, the final determination of the presence of TiO must await space-based observations. We conclude that the 4-UT mode of ESPRESSO is an excellent testbed for achieving high S/N on relatively faint targets, paving the way for future observations with the ELT.

Observations of molecular lines are a key tool to determine the main physical properties of prestellar cores. However, not all the information is retained in the observational process or easily interpretable, especially when a larger number of physical properties and spectral features are involved. We present a methodology to link the information in the synthetic spectra with the actual information in the simulated models (i.e., their physical properties), in particular, to determine where the information resides in the spectra. We employ a 1D gravitational collapse model with advanced thermochemistry, from which we generate synthetic spectra. We then use neural network emulations and the SHapley Additive exPlanations (SHAP), a machine learning technique, to connect the models' properties to the specific spectral features. Thanks to interpretable machine learning, we find several correlations between synthetic lines and some of the key model parameters, such as the cosmic-ray ionization radial profile, the central density, or the abundance of various species, suggesting that most of the information is retained in the observational process. Our procedure can be generalized to similar scenarios to quantify the amount of information lost in the real observations. We also point out the limitations for future applicability.

We report the discovery and characterization of two sub-Saturns from the Transiting Exoplanet Survey Satellite (TESS) using high- resolution spectroscopic observations from the MaHPS spectrograph at the Wendelstein Observatory and the SOPHIE spectrograph at the Haute-Provence Observatory. Combining photometry from TESS, KeplerCam, LCOGT, and MuSCAT2, along with the radial velocity measurements from MaHPS and SOPHIE, we measured precise radii and masses for both planets. TOI-5108 b is a sub-Saturn, with a radius of 6.6 ± 0.1 R_⊕ and a mass of 32 ± 5 M_⊕. TOI-5786 b is similar to Saturn, with a radius of 8.54 ± 0.13 R_⊕ and a mass of 73 ± 9 M_⊕. The host star for TOI-5108 b is a moderately bright (Vmag 9.75) G-type star. TOI-5786 is a slightly dimmer (Vmag 10.2) F-type star. Both planets are close to their host stars, with periods of 6.75 days and 12.78 days, respectively. This puts TOI-5108 b just within the bounds of the Neptune desert, while TOI-5786 b is right above the upper edge. We estimated hydrogen-helium (H/He) envelope mass fractions of 38% for TOI-5108 b and 74% for TOI-5786 b. However, when using a model for the interior structure that includes tidal effects, the envelope fraction of TOI-5108 b could be much lower (~20%), depending on the obliquity. We estimated mass-loss rates between 1.0 x 10⁹ g/s and 9.8 x 10⁹ g/s for TOI-5108 b and between 3.6 x 10⁸ g/s and 3.5 x 10⁹ g/s for TOI-5786 b. Given their masses, both planets could be stable against photoevaporation. Furthermore, at these mass-loss rates, there is likely no detectable signal in the metastable helium triplet with the James Webb Space Telescope (JWST). We also detected a transit signal for a second planet candidate in the TESS data of TOI-5786, with a period of 6.998 days and a radius of 3.83 ± 0.16 R_⊕. Using our RV data and photodynamical modeling, we were able to provide a 3-σ upper limit of 26.5 M_⊕ for the mass of the potential inner companion to TOI-5786 b.

We transform the one-loop four-point type I open superstring gluon amplitude to correlation functions on the celestial sphere including both the (non-)orientable planar and non-planar sector. This requires a Mellin transform with respect to the energies of the scattered strings, as well as to integrate over the open-string worldsheet moduli space. After accomplishing the former we obtain celestial string integrands with remaining worldsheet integrals <mml:math altimg="si1.svg"><mml:mi mathvariant="normal">Ψ</mml:mi><mml:mrow><mml:mo stretchy="true">(</mml:mo><mml:mi>β</mml:mi><mml:mo stretchy="true">)</mml:mo></mml:mrow></mml:math>, where β is related to the conformal scaling dimensions of the conformal primary operators under consideration. Employing an alternative approach of performing an <mml:math altimg="si2.svg"><mml:msup><mml:mrow><mml:mi>α</mml:mi></mml:mrow><mml:mrow><mml:mo>‧</mml:mo></mml:mrow></mml:msup></mml:math>-expansion of the open superstring amplitude first and Mellin transforming afterwards, we obtain a fully integrated expression, capturing the pole structure in the β-plane. The same analysis is performed at tree-level yielding similar results. We conclude by solving <mml:math altimg="si1.svg"><mml:mi mathvariant="normal">Ψ</mml:mi><mml:mrow><mml:mo stretchy="true">(</mml:mo><mml:mi>β</mml:mi><mml:mo stretchy="true">)</mml:mo></mml:mrow></mml:math> for specific values of β, consistently reproducing the results of the <mml:math altimg="si2.svg"><mml:msup><mml:mrow><mml:mi>α</mml:mi></mml:mrow><mml:mrow><mml:mo>‧</mml:mo></mml:mrow></mml:msup></mml:math>-expansion ansatz. In all approaches we find that the dependence on <mml:math altimg="si2.svg"><mml:msup><mml:mrow><mml:mi>α</mml:mi></mml:mrow><mml:mrow><mml:mo>‧</mml:mo></mml:mrow></mml:msup></mml:math> reduces to that of a simple overall factor of <mml:math altimg="si3.svg"><mml:msup><mml:mrow><mml:mo stretchy="true">(</mml:mo><mml:msup><mml:mrow><mml:mi>α</mml:mi></mml:mrow><mml:mrow><mml:mo>‧</mml:mo></mml:mrow></mml:msup><mml:mo stretchy="true">)</mml:mo></mml:mrow><mml:mrow><mml:mi>β</mml:mi><mml:mo linebreak="badbreak" linebreakstyle="after">‑</mml:mo><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:math> at loop and <mml:math altimg="si185.svg"><mml:msup><mml:mrow><mml:mo stretchy="true">(</mml:mo><mml:msup><mml:mrow><mml:mi>α</mml:mi></mml:mrow><mml:mrow><mml:mo>‧</mml:mo></mml:mrow></mml:msup><mml:mo stretchy="true">)</mml:mo></mml:mrow><mml:mrow><mml:mi>β</mml:mi></mml:mrow></mml:msup></mml:math> at tree level, consistent with previous literature.

We performed a detailed spectroscopic analysis of three extremely metal-poor RR Lyrae stars, exploring uncharted territories at these low metallicities for this class of stars. Using high-resolution spectra acquired with HARPS-N at TNG, UVES at VLT, and PEPSI at LBT, and employing Non-Local Thermodynamic Equilibrium (NLTE) spectral synthesis calculations, we provide abundance measurements for Fe, Al, Mg, Ca, Ti, Mn, and Sr. Our findings indicate that the stars have metallicities of [Fe/H] = ‑3.40 ± 0.05, ‑3.28 ± 0.02, and ‑2.77 ± 0.05 for HD 331986, DO Hya, and BPS CS 30317-056, respectively. Additionally, we derived their kinematic and dynamical properties to gain insights into their origins. Interestingly, the kinematics of one star (HD 331986) is consistent with the Galactic disc, while the others exhibit Galactic halo kinematics, albeit with distinct chemical signatures. We compared the [Al/Fe] and [Mg/Mn] ratios of the current targets with recent literature estimates to determine whether these stars were either accreted or formed in situ, finding that the adopted chemical diagnostics are ineffective at low metallicities ([Fe/H] ≲ ‑1.5). Finally, the established horizontal branch evolutionary models, indicating that these stars arrive at hotter temperatures on the Zero-Age Horizontal Branch (ZAHB) and then transition into RR Lyrae stars as they evolve, fully support the existence of such low-metallicity RR Lyrae stars. As a consequence, we can anticipate detecting more of them when larger samples of spectra become available from upcoming extensive observational campaigns. ⋆ Based on observations acquired at the Telescopio Nazionale Galileo under program A43DDT3, on a DDT program with PEPSI at LBT (2021-2022, PI Crestani) and on VLT ESO programs 69.C-0423(A) and 165.N-0276(A).

We present constraints on the <inline-formula><mml:math display="inline"><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>R</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> gravity model using a sample of 1005 galaxy clusters in the redshift range 0.25–1.78 that have been selected through the thermal Sunyaev-Zel'dovich effect from South Pole Telescope data and subjected to optical and near-infrared confirmation with the multicomponent matched filter algorithm. We employ weak gravitational lensing mass calibration from the Dark Energy Survey Year 3 data for 688 clusters at <inline-formula><mml:math display="inline"><mml:mi>z</mml:mi><mml:mo><</mml:mo><mml:mn>0.95</mml:mn></mml:math></inline-formula> and from the Hubble Space Telescope for 39 clusters with <inline-formula><mml:math display="inline"><mml:mn>0.6</mml:mn><mml:mo><</mml:mo><mml:mi>z</mml:mi><mml:mo><</mml:mo><mml:mn>1.7</mml:mn></mml:math></inline-formula>. Our cluster sample is a powerful probe of <inline-formula><mml:math display="inline"><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>R</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> gravity, because this model predicts a scale-dependent enhancement in the growth of structure, which impacts the halo mass function (HMF) at cluster mass scales. To account for these modified gravity effects on the HMF, our analysis employs a semianalytical approach calibrated with numerical simulations. Combining calibrated cluster counts with primary cosmic microwave background temperature and polarization anisotropy measurements from the Planck 2018 release, we derive robust constraints on the <inline-formula><mml:math display="inline"><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>R</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> parameter <inline-formula><mml:math display="inline"><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>R</mml:mi><mml:mn>0</mml:mn></mml:mrow></mml:msub></mml:math></inline-formula>. Our results, <inline-formula><mml:math display="inline"><mml:msub><mml:mi>log</mml:mi><mml:mn>10</mml:mn></mml:msub><mml:mo stretchy="false">|</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>R</mml:mi><mml:mn>0</mml:mn></mml:mrow></mml:msub><mml:mo stretchy="false">|</mml:mo><mml:mo><</mml:mo><mml:mo>-</mml:mo><mml:mn>5.32</mml:mn></mml:math></inline-formula> at the 95% credible level, are the tightest current constraints on <inline-formula><mml:math display="inline"><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>R</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> gravity from cosmological scales. This upper limit rules out <inline-formula><mml:math display="inline"><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>R</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula>-like deviations from general relativity that result in more than a <inline-formula><mml:math display="inline"><mml:mo>∼</mml:mo><mml:mn>20</mml:mn><mml:mo>%</mml:mo></mml:math></inline-formula> enhancement of the cluster population on mass scales <inline-formula><mml:math display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>M</mml:mi></mml:mrow><mml:mrow><mml:mn>200</mml:mn><mml:mi mathvariant="normal">c</mml:mi></mml:mrow></mml:msub><mml:mo>></mml:mo><mml:mn>3</mml:mn><mml:mo>×</mml:mo><mml:msup><mml:mrow><mml:mn>10</mml:mn></mml:mrow><mml:mrow><mml:mn>14</mml:mn></mml:mrow></mml:msup><mml:msub><mml:mrow><mml:mi>M</mml:mi></mml:mrow><mml:mrow><mml:mo stretchy="false">⊙</mml:mo></mml:mrow></mml:msub></mml:mrow></mml:math></inline-formula>.

In the present study, we employ three distinct, physically motivated speed of sound bounds to construct hybrid models, where the high-density phase is described by the maximally stiff equation of state. In particular, we consider the bounds related to special relativity, relativistic kinetic theory, and conformality. The low-density hadronic phase is described by a state-of-the-art microscopic relativistic Brueckner-Hartree-Fock theory. This work aims to access the effect of the different speed of sound constraints on the relevant parameter space of the key parameters of first-order phase transitions by utilizing recent astronomical data. This involves a systematic analysis that also includes two distinct schemes for the construction of hybrid models (abrupt and smooth). Finally, a relevant discussion is conducted on the possible occurrence of a thermodynamic inconsistency that is related to the stability of the high-density phase over hadronic matter at large densities.

Context. The intense X-ray and UV emission of some active M stars has raised questions about the habitability of planets around M-type stars. Aims. We aim to determine the unbiased distribution of X-ray luminosities in complete, volume-limited samples of nearby M dwarfs, and compare them to those of K and G dwarfs. Methods. We constructed volume-complete samples of 205 M stars with a spectral type ≤ M6 within 10 pc of the Sun, 129 K stars within 16 pc, and 107 G stars within 20 pc. We used X-ray data from Chandra, XMM-Newton, eROSITA, and ROSAT to obtain the X-ray luminosities of the stars. Results. Our samples reach an X-ray detection completeness of 85%, 86%, and 80% for M, K, and G stars, respectively. The fractional X-ray luminosities relative to the bolometric luminosities, log(L_X/L_bol), of the M stars show a bimodal distribution, with one peak at around ‑5, mostly contributed by early M stars (M0–M4), and another peak around ‑3.5, contributed mainly by M4–M6 stars. The comparison of the different spectral classes shows that 63% of all M stars in our sample (80% of the M stars with a spectral type < M4) have L_X/L_bol values that are within the central 80% quantile of the distribution function for G stars. In addition, 55% of all M stars in our sample (and 72% of the M stars with a spectral type < M4) have L_X/L_bol less than 10 times the solar value. Conclusions. The X-ray activity levels of the majority (≳60%) of nearby M dwarfs no later than M6 are actually not higher than the typical (80% quantile) levels for G-type stars. The X-ray irradiation of habitable-zone planets around these stars should therefore not present a specific problem for their habitability.

The formation details of globular clusters (GCs) are still poorly understood due to their old ages and the lack of detailed observations of their formation. A large variety of models for the formation and evolution of GCs have been created to improve our understanding of their origins, based on GC properties observed at <inline-formula><tex-math id="TM0001" notation="LaTeX">$z=0$</tex-math></inline-formula>. We present the first side-by-side comparison of six current GC formation models with respect to their predictions for the GC ages and formation redshifts in Milky Way (MW)-like galaxies. We find that all the models are capable of forming most of the surviving GCs at more than <inline-formula><tex-math id="TM0002" notation="LaTeX">$10 \,\mathrm{G}{\rm {yr}}$</tex-math></inline-formula> ago, in general agreement with the observation that most GCs are old. However, the measured MW GC ages are still systematically older than those predicted in the galaxies of four of the models. Investigating the variation of modelled GC age distributions for general MW-mass galaxies, we find that some of the models predict that a significant fraction of MW-mass galaxies would entirely lack a GC population older than <inline-formula><tex-math id="TM0003" notation="LaTeX">$10 \,\mathrm{G}{\rm {yr}}$</tex-math></inline-formula>, whereas others predict that all MW-mass galaxies have a significant fraction of old GCs. This will have to be further tested in upcoming surveys, as systems without old GCs in that mass range are currently not known. Finally, we show that the models predict different formation redshifts for the oldest surviving GCs, highlighting that models currently disagree about whether the recently observed young star clusters at high redshifts could be the progenitors of today's GCs.

Strongly lensed supernovae (SNe) are a rare class of transient that can offer tight cosmological constraints that are complementary to methods from other astronomical events. We present a follow-up study of one recently discovered strongly lensed SN, the quadruply imaged type Ia SN 2022qmx (aka "SN Zwicky"), at z = 0.3544. We measure updated, template-subtracted photometry for SN Zwicky and derive improved time delays and magnifications. This is possible because SNe are transient, fading away after reaching their peak brightness. Specifically, we measure point-spread-function photometry for all four images of SN Zwicky in three Hubble Space Telescope WFC3/UVIS passbands (F475W, F625W, and F814W) and one WFC3/IR passband (F160W), with template images taken ∼11 months after the epoch in which the SN images appear. We find consistency to within 2σ between lens-model-predicted time delays (≲1 day) and measured time delays with HST colors (≲2 days), including the uncertainty from chromatic microlensing that may arise from stars in the lensing galaxy. The standardizable nature of SNe Ia allows us to estimate absolute magnifications for the four images, with images A and C being elevated in magnification compared to lens model predictions by about 6σ and 3σ, respectively, confirming previous work. We show that millilensing or differential dust extinction is unable to explain these discrepancies, and we find evidence for the existence of microlensing in images A, C, and potentially D that may contribute to the anomalous magnification.

We identify a chain of galaxies along an almost straight line in the nearby Universe with a projected length of ~5 Mpc. The galaxies are distributed within projected distances of only 7–105 kpc from the axis of the identified filament. They have redshifts in a very small range of z = 0.0361‑0.0370 so that their radial velocities are consistent with galaxy proper motions. The filament galaxies are mainly star forming and have stellar masses in a range of 10^9.1‑10^10.7 M_⊙. We search for systems with similar geometrical properties in the full-sky mock galaxy catalog of the MillenniumTNG simulations and find that, although such straight filaments are unusual and rare, they are predicted by ΛCDM simulations (4% incidence). We study the cold H I gas in a 1.3 Mpc section of the filament through H I 21 cm emission line observations and detect 11 H I sources, many more than expected from the H I mass function in a similar volume. They have H I masses 10^8.5‑10^9.5 M_⊙ and are mostly within ~120 kpc projected distance from the filament axis. None of these H I sources has a confirmed optical counterpart. Their darkness together with their large H I 21 cm line widths indicates that they contain gas that might not yet be virialized. These clouds must be marking the peaks of the dark matter and H I distributions over large scales within the filament. The presence of such gas clouds around the filament spines is predicted by simulations, but this is the first time that the existence of such clouds in a filament is observationally confirmed.

Observed low-mass galaxies with nuclear star clusters (NSCs) can host accreting massive black holes (MBH). We present simulations of dwarf galaxies (<inline-formula><tex-math id="TM0001" notation="LaTeX">$M_{\mathrm{baryon}} \sim 0.6\!-\!2.4 \times 10^8 \rm \, M_\odot$</tex-math></inline-formula>) at solar mass resolution (<inline-formula><tex-math id="TM0002" notation="LaTeX">$0.5\rm \, M_\odot \lt \mathit{ m}_{\mathrm{gas}} \lt 4 \rm \, M_\odot$</tex-math></inline-formula>) with a multiphase interstellar medium (ISM) and investigate the impact of NSCs on MBH growth and nuclear star formation (SF). The GRIFFIN simulation model includes non-equilibrium low temperature cooling, chemistry and the effect of H II regions and supernovae (SNe) from massive stars. Individual stars are sampled down to 0.08 <inline-formula><tex-math id="TM0003" notation="LaTeX">$\rm M_\odot$</tex-math></inline-formula> and their non-softened gravitational interactions with MBHs are computed with the regularized KETJU integrator. MBHs with masses in the range of <inline-formula><tex-math id="TM0004" notation="LaTeX">$10^2 \!-\! 10^5 \, \rm M_\odot$</tex-math></inline-formula> are represented by accreting sink particles without feedback. We find that the presence of NSCs boost nuclear SF (i.e. NSC growth) and MBH accretion by funneling gas to the central few parsecs. Low-mass MBHs grow more rapidly on <inline-formula><tex-math id="TM0005" notation="LaTeX">$\sim 600$</tex-math></inline-formula> Myr time-scales, exceeding their Eddington rates at peak accretion. MBH accretion and nuclear SF is episodic (i.e. leads to multiple stellar generations), coeval and regulated by SN explosions. On 40-60 Myr time-scales the first SN of each episode terminates MBH accretion and nuclear SF. Without NSCs, low-mass MBHs do not grow and MBH accretion and reduced nuclear SF become irregular and uncorrelated. This study gives the first insights into the possible co-evolution of MBHs and NSCs in low-mass galaxies and highlights the importance of considering dense NSCs in galactic studies of MBH growth.

Using two-dimensional general relativistic resistive magnetohydrodynamic simulations, we investigate the properties of the sheath separating the black hole jet from the surrounding medium. We find that the electromagnetic power flowing through the jet sheath is comparable to the overall accretion power of the black hole. The sheath is an important site of energy dissipation as revealed by the copious appearance of reconnection layers and plasmoid chains. About 20% of the sheath power is dissipated between 2 and 10 gravitational radii. The plasma in the dissipative sheath moves along a nearly paraboloidal surface with transrelativistic bulk motions dominated by the radial component, whose dimensionless 4-velocity is ∼1.2 ± 0.5. In the frame moving with the mean (radially dependent) velocity, the distribution of stochastic bulk motions resembles a Maxwellian with an "effective bulk temperature" of ∼100 keV. Scaling the global simulation to Cygnus X-1 parameters gives a rough estimate of the Thomson optical depth across the jet sheath, ∼0.01–0.1, and it may increase in future magnetohydrodynamic simulations with self-consistent radiative losses. These properties suggest that the dissipative jet sheath may be a viable "coronal" region, capable of upscattering seed soft photons into a hard, nonthermal tail, as seen during the hard states of X-ray binaries and active galactic nuclei.

Cosmic-ray acceleration processes in astrophysical plasmas are often investigated with fully kinetic or hybrid kinetic numerical simulations, which enable us to describe a detailed microphysics of particle energization mechanisms. Tracing of individual particles in such simulations is especially useful in this regard. However, visually inspecting particle trajectories introduces a significant amount of bias and uncertainty, making it challenging to pinpoint specific acceleration mechanisms. Here, we present a novel approach utilizing neural networks to assist in the analysis of individual particle data. We demonstrate the effectiveness of this approach using the dataset from our recent particle-in-cell (PIC) simulations of non-relativistic perpendicular shocks, which consists of 252 000 electrons, each characterized by their position, momentum, and electromagnetic field at particle's position, recorded in a time series of 1200 time steps. These electrons cross a region affected by the electrostatic Buneman instability, and a small percentage of them attain high energies. We perform classification, regression, and anomaly detection algorithms on the dataset by using a convolutional neural network, a multi-layer perceptron, and an autoencoder. Despite the noisy and imbalanced dataset, all methods demonstrate the capability to differentiate between thermal and accelerated electrons with remarkable accuracy. The proposed methodology may considerably simplify particle classification in large-scale PIC and hybrid simulations.

The braking torque that dictates the timing properties of magnetars is closely tied to the large-scale dipolar magnetic field on their surface. The formation of this field has been a topic of ongoing debate. One proposed mechanism, based on macroscopic principles, involves an inverse cascade within the neutron star's crust. However, this phenomenon has not been observed in realistic simulations. In this study, we provide compelling evidence supporting the feasibility of the inverse cascading process in the presence of an initial helical magnetic field within realistic neutron star crusts and discuss its contribution to the amplification of the large-scale magnetic field. Our findings, derived from a systematic investigation that considers various coordinate systems, peak wavenumber positions, crustal thicknesses, magnetic boundary conditions, and magnetic Lundquist numbers, reveal that the specific geometry of the crustal domain–with its extreme aspect ratio–requires an initial peak wavenumber from small-scale structures for the inverse cascade to occur. However, this same aspect ratio confines the cascade to structures on the scale of the crust, making the formation of a large-scale dipolar surface field unlikely. Despite these limitations, the inverse cascade remains a significant factor in the magnetic field evolution within the crust and may help explain highly magnetized objects with weak surface dipolar fields, such as low-field magnetars and central compact objects.

High-cadence high-resolution spectroscopic observations of infant Type II supernovae (SNe) represent an exquisite probe of the atmospheres and winds of exploding red-supergiant (RSG) stars. Using radiation hydrodynamics and radiative transfer calculations, we studied the gas and radiation properties during and after the phase of shock breakout, considering RSG star progenitors enshrouded within a circumstellar material (CSM) that varies in terms of the extent, density, and velocity profile. In all cases, the original, unadulterated CSM structure is probed only at the onset of shock breakout, seen in high-resolution spectra as narrow, often blueshifted emission components, possibly with an additional absorption trough. As the SN luminosity rises during breakout, radiative acceleration of the unshocked CSM starts, leading to a broadening of the "narrow" lines by several 100 (up to several 1000) km s^‑1, depending on the CSM properties. This acceleration is at its maximum close to the shock, where the radiative flux is greater and thus typically masked by optical-depth effects. Generally, the narrow-line broadening is greater for more compact, tenuous CSM because of the proximity to the shock where the flux is born; it is smaller in the denser and more extended CSM. Narrow-line emission should show a broadening that slowly increases first (the line forms further out in the original wind), then sharply rises (the line forms in a region that is radiatively accelerated), before decreasing until late times (the line forms further away in regions more weakly accelerated). Radiative acceleration is expected to inhibit X-ray emission during the early (IIn) phase. Although high spectral resolution is critical at the earliest times to probe the original slow wind, the radiative acceleration and the associated line broadening may be captured with medium resolution. This would allow for a simultaneous view of narrow, Doppler-broadened line emission, as well as extended, electron-scattering broadened emission.

Low-metallicity environments are subject to inefficient cooling. They also have low dust-to-gas ratios and therefore less efficient photoelectric (PE) heating than in solar-neighbourhood conditions, where PE heating is one of the most important heating processes in the warm neutral interstellar medium (ISM). We perform magnetohydrodynamic simulations of stratified ISM patches with a gas metallicity of 0.02 Z<inline-formula><tex-math id="TM0001" notation="LaTeX">$_\odot$</tex-math></inline-formula> as part of the SILCC project. The simulations include non-equilibrium chemistry, heating, and cooling of the low-temperature ISM as well as anisotropic cosmic-ray (CR) transport, and stellar tracks. We include stellar feedback in the form of far-ultraviolet and ionizing (FUV and extreme ultraviolet, EUV) radiation, massive star winds, supernovae, and CR injection. From the local CR energy density, we compute a CR heating rate that is variable in space and time. In this way, we can compare the relative impact of PE and CR heating on the metal-poor ISM and find that CR heating can dominate over PE heating. Models with a uniform CR ionization rate of <inline-formula><tex-math id="TM0002" notation="LaTeX">$\zeta$</tex-math></inline-formula> = 3 <inline-formula><tex-math id="TM0003" notation="LaTeX">$\times$</tex-math></inline-formula> 10<inline-formula><tex-math id="TM0004" notation="LaTeX">$^{-17}$</tex-math></inline-formula> s<inline-formula><tex-math id="TM0005" notation="LaTeX">$^{-1}$</tex-math></inline-formula> suppress or severely delay star formation, since they provide a larger amount of energy to the ISM due to CR heating. Models with a variable CR ionization rate form stars predominantly in pristine regions with low PE heating and CR ionization rates where the metal-poor gas is able to cool efficiently. Because of the low metallicity, the amount of formed stars in all runs is not enough to trigger outflows of gas from the mid-plane.

We present a complete set of physical parameters for three early-type eclipsing binary systems in the Large Magellanic Cloud (LMC): OGLE LMC-ECL-17660, OGLE LMC-ECL-18794, and HV 2274, together with the orbital solutions. The first and third systems comprise B-type stars, while the second has O-type components and exhibits a total eclipse. We performed a complex analysis that included modeling light and radial velocity curves, O ‑ C analysis, and additional non-LTE spectroscopic analysis for the O-type system. We found that OGLE LMC-ECL-17660 is at least a triple, and tentatively, a quadruple. A significant nonlinear period decrease was determined for HV 2274. Its origin is unclear, possibly due to a faint, low-mass companion on a wide orbit. The analyzed components have masses ranging from 11.7 M_⊙ to 22.1 M_⊙, radii from 7.0 R_⊙ to 14.2 R_⊙, and temperatures between 22,500 and 36,000 K. For HV 2274, the precision of our masses and radii is about six times higher than in previous studies. The position of the components of all six systems analyzed in this series on the mass–luminosity and mass–radius diagrams indicates they are evolutionarily advanced on the main sequence. Our sample contributes significantly to the knowledge of physical parameters of early-type stars in the mass range of 11 M_⊙–23 M_⊙. A new mass–luminosity relation for O- and B-type stars in the LMC is provided. Additionally, we used the measured apsidal motion of the systems to compare the observational and theoretical internal structure constant.

The interaction of relativistic particles with plasma, relevant to astrophysics and laboratory-based plasma wakefield accelerators, is governed by plasma instabilities leading to electromagnetic fluctuations and filamentary structures. Wakefield-driven and current-driven instabilities of particle beams with a well-defined extent are analysed through theory and particle-in-cell simulations and compared to experimental observations, providing a basis for experimental designs.

We compute analytically the three-loop correlation function of the local operator tr ϕ³ inserted into three on-shell states, in maximally supersymmetric Yang-Mills theory. The result is expressed in terms of Chen iterated integrals. We also present our result using generalised polylogarithms, and evaluate them numerically, finding agreement with a previous numerical result in the literature. We observe that the result depends on fewer kinematic singularities compared to individual Feynman integrals. Furthermore, upon choosing a suitable definition of the finite part, we find that the latter satisfies powerful symbol adjacency relations similar to those previously observed for the tr ϕ² case.

Strongly lensed quasars provide valuable insights into the rate of cosmic expansion, the distribution of dark matter in foreground deflectors, and the characteristics of quasar hosts. However, detecting them in astronomical images is difficult due to the prevalence of non-lensing objects. To address this challenge, we developed a generative deep learning model called VariLens, built upon a physics-informed variational autoencoder. This model seamlessly integrates three essential modules: image reconstruction, object classification, and lens modeling, offering a fast and comprehensive approach to strong lens analysis. VariLens is capable of rapidly determining both (1) the probability that an object is a lens system and (2) key parameters of a singular isothermal ellipsoid (SIE) mass model – including the Einstein radius (θ_E), lens center, and ellipticity – in just milliseconds using a single CPU. A direct comparison of VariLens estimates with traditional lens modeling for 20 known lensed quasars within the Subaru Hyper Suprime-Cam (HSC) footprint shows good agreement, with both results consistent within 2σ for systems with θ_E < 3″. To identify new lensed quasar candidates, we began with an initial sample of approximately 80 million sources, combining HSC data with multiwavelength information from Gaia, UKIRT, VISTA, WISE, eROSITA, and VLA. After applying a photometric preselection aimed at locating z > 1.5 sources, the number of candidates was reduced to 710 966. Subsequently, VariLens highlights 13 831 sources, each showing a high likelihood of being a lens. A visual assessment of these objects results in 42 promising candidates that await spectroscopic confirmation. These results underscore the potential of automated deep learning pipelines to efficiently detect and model strong lenses in large datasets, substantially reducing the need for manual inspection.

We present a computation of the one-loop QCD corrections to top-quark pair production in association with a $W$ boson, including terms up to order $\varepsilon^2$ in dimensional regularization. Providing a first glimpse into the complexity of the corresponding two-loop amplitude, this result is a first step towards a description of this process at next-to-next-to-leading order (NNLO) in QCD. We perform a tensor decomposition and express the corresponding form factors in terms of a basis of independent special functions with compact rational coefficients, providing a structured framework for future developments. In addition, we derive an explicit analytic representation of the form factors, valid up to order $\varepsilon^0$, expressed in terms of logarithms and dilogarithms. For the complete set of special functions required, we obtain a semi-numerical solution based on generalized power series expansion.

The post-inflationary Peccei-Quinn (PQ) symmetry breaking scenario provides a unique opportunity to pinpoint the QCD axion dark matter mass, which is a crucial input for laboratory experiments that are designed for probing specific mass ranges. Predicting their mass requires a precise knowledge of how axions are produced from the decay of topological defects in the early Universe that are inevitably formed. In this contribution, we present recent results on the analysis of the spectrum of axions radiated from global strings based on large scale numerical simulations of the cosmological evolution of the PQ field on a static lattice. We highlight several systematic effects that have been overlooked in previous works, such as the dependence on the initial conditions, contaminations due to oscillations in the spectrum, and discretisation effects; some of which could explain the discrepancy in the current literature. Taking these uncertainties into account and performing the extrapolation to cosmologically relevant string tensions, we find that the dark matter mass is predicted to be in the range of $95\,\mu\text{eV} \lesssim m_a \lesssim 450 \, \mu\text{eV}$, which will be probed by some of the next generation direct detection experiments.

We have observed the late Class I protostellar source Elias 29 at a spatial resolution of 70 au with the Atacama Large Millimeter/submillimeter Array as part of the FAUST Large Program. We focus on the line emission of SO, while that of ³⁴SO, C¹⁸O, CS, SiO, H¹³CO⁺, and DCO⁺ are used supplementarily. The spatial distribution of the SO rotational temperature (T_rot(SO)) is evaluated by using the intensity ratio of its two rotational excitation lines. Besides in the vicinity of the protostar, two hot spots are found at a distance of 500 au from the protostar; T_rot(SO) locally rises to 53<inline-formula> </inline-formula> K at the interaction point of the outflow and the southern ridge, and 72<inline-formula> </inline-formula> K within the southeastern outflow probably due to a jet-driven bow shock. However, the SiO emission is not detected at these hot spots. It is likely that active gas accretion through the disk-like structure and onto the protostar still continues even at this evolved protostellar stage, at least sporadically, considering the outflow/jet activities and the possible infall motion previously reported. Interestingly, T_rot(SO) is as high as 20–30 K even within the quiescent part of the southern ridge apart from the protostar by 500–1000 au without clear kinematic indication of current outflow/jet interactions. Such a warm condition is also supported by the low deuterium fractionation ratio of HCO⁺ estimated by using the H¹³CO⁺ and DCO⁺ lines. The B-type star HD147889 ∼0.5 pc away from Elias 29, previously suggested as a heating source for this region, is likely responsible for the warm condition of Elias 29.

In this paper, we define absorptive Compton amplitudes, which capture the absorption factor for waves of spin-weight-<inline-formula><mml:math display="inline"><mml:mi>s</mml:mi></mml:math></inline-formula> scattering in black hole perturbation theory. At the leading order, in the <inline-formula><mml:math display="inline"><mml:mi>G</mml:mi><mml:mi>M</mml:mi><mml:mi>ω</mml:mi></mml:math></inline-formula> expansion, such amplitudes are purely imaginary and expressible as contact terms. Equipped with these amplitudes we compute the mass change in black hole scattering events via the Kosower-Maybee-O'Connell formalism, where the rest mass of a Schwarzschild/Kerr black hole is modified due to absorption of gravitational, electromagnetic, or scalar fields sourced by other compact object. We reproduced the power loss previously computed in the post-Newtonian expansion. The results presented here hold for similar mass ratios and generic spin orientation, while keeping the Kerr spin parameter to lie in the physical region <inline-formula><mml:math display="inline"><mml:mi>χ</mml:mi><mml:mo>≤</mml:mo><mml:mn>1</mml:mn></mml:math></inline-formula>.

Transit spectroscopy usually relies on the integration of one or several transits to achieve the signal-to-noise ratio (S/N) necessary to resolve spectral features. Consequently, high-S/N observations of exoplanet atmospheres, where we can forgo integration, are essential for disentangling the complex chemistry and dynamics beyond global trends. In this study, we combined two partial 4-UT transits of the ultrahot Jupiter WASP-121 b, observed with the ESPRESSO at the European Southern Observatory's Very Large Telescope in order to revisit its titanium chemistry. Through cross-correlation analysis, we achieved detections of H I, Li I, Na I, K I, Mg I, Ca I, Ti I, V I, Cr I, Mn I, Fe I, Fe II, Co I, Ni I, Ba II, Sr I, and Sr II. Additionally, narrow-band spectroscopy allowed us to resolve strong single lines, resulting in significant detections of Hα, Hβ, Hγ, Li I, Na I, K I, Mg I, Ca II, Sr I, Sr II, and Mn I. Our most notable finding is the high-significance detection of Ti I (∼5σ per spectrum, and ∼19σ stacked in the planetary rest frame). Comparison with atmospheric models reveals that Ti I is indeed depleted compared to V I. We also resolve the planetary velocity traces of both Ti I and V I, with Ti I exhibiting a significant blueshift toward the end of the transit. This suggests that Ti I primarily originates from low-latitude regions within the super-rotating jet observed in WASP-121 b. Our observations suggest limited mixing between the equatorial jet and the mid-latitudes, in contrast with model predictions from General Circulation Models. We also report the non-detection of TiO, which we attribute to inaccuracies in the line list that could hinder its detection, even if present. Thus, the final determination of the presence of TiO must await space-based observations. We conclude that the 4-UT mode of ESPRESSO is an excellent testbed for achieving high S/N on relatively faint targets, paving the way for future observations with the Extremely Large Telescope.

If primordial black holes (PBHs) of asteroidal mass make up the entire dark matter, they could be detectable through their gravitational influence in the solar system. In this work, we study the perturbations that PBHs induce on the orbits of planets. Detailed numerical simulations of the solar system, embedded in a halo of PBHs, are performed. We find that the gravitational effect of the PBHs is dominated by the closest encounter. Using the Earth–Mars distance as an observational probe, we show that the perturbations are smaller than the current measurement uncertainties and thus PBHs are not directly constrained by solar system ephemerides. We estimate that an improvement in the ranging accuracy by an order of magnitude or the extraction of signals well below the noise level is required to detect the gravitational influence of PBHs in the solar system in the foreseeable future.

Context. Infall of interstellar material is a potential non-planetary origin of pressure bumps in protoplanetary disks. While pressure bumps arising from other mechanisms have been numerically demonstrated to promote planet formation, the impact of infall-induced pressure bumps remains unexplored. Aims. We aim to investigate the potential for planetesimal formation in an infall-induced pressure bump, starting with sub-micrometer-sized dust grains, and to identify the conditions most conducive to triggering this process. Methods. We developed a numerical model that integrates axisymmetric infall, dust drift, and dust coagulation, along with planetesimal formation via streaming instability. Our parameter space includes gas viscosity, dust fragmentation velocity, initial disk mass, characteristic disk radius, infall rate and duration, as well as the location and width of the infall region. Results. An infall-induced pressure bump can trap dust from both the infalling material and the outer disk, promoting dust growth. The locally enhanced dust-to-gas ratio triggers streaming instability, forming a planetesimal belt inside the central infall location until the pressure bump is smoothed out by viscous gas diffusion. Planetesimal formation is favored by a massive, narrow streamer infalling onto a low-viscosity, low-mass, and spatially extended disk containing dust with a high fragmentation velocity. This configuration enhances the outward drift speed of dust on the inner side of the pressure bump, while also ensuring the prolonged persistence of the pressure bump. Planetesimal formation can occur even if the infalling material consists solely of gas. Conclusions. A pressure bump induced by infall is a favorable site for dust growth and planetesimal formation, and this mechanism does not require a preexisting massive planet to create the bump.

Context. Chemical clocks based on [s-process element/α element] ratios are widely used to estimate the ages of Galactic stellar populations. However, the [s/α] versus age relations are not universal, varying with metallicity, location in the Galactic disc, and specific s-process elements. Moreover, current Galactic chemical evolution models struggle to reproduce the observed [s/α] increase at young ages, particularly for Ba. Aims. Our aim is to provide chemical evolution models for different regions of the Milky Way (MW) disc in order to identify the conditions required to reproduce the observed [s/H], [s/Fe], and [s/α] versus age relations. Methods. We adopted a detailed multi-zone chemical evolution model for the MW including state-of-the-art nucleosynthesis prescriptions for neutron-capture elements. The s-process elements were synthesised in asymptotic giant branch (AGB) stars and rotating massive stars, while r-process elements originate from neutron star mergers and magneto-rotational supernovae. Starting from a baseline model that successfully reproduces a wide range of neutron-capture element abundance patterns, we explored variations in gas infall/star formation history scenarios, AGB yield dependencies on progenitor stars, and rotational velocity distributions for massive stars. We compared the results of our model with the open clusters dataset from the sixth data release of the Gaia-ESO survey. Results. A three-infall scenario for disc formation aligns better with the observed trends. The models capture the rise of [s/α] with age in the outer regions but fail towards the inner regions, with larger discrepancies for second s-process peak elements. Specifically, Ba production in the last 3 Gyr of chemical evolution would need to increase by slightly more than half to match the observations. The s-process contribution from low-mass (∼1.1 M_⊙) AGB stars helps reconcile predictions with data but it requires a too-strong increase that is not predicted by current nucleosynthesis calculations, even with a potential i-process contribution. Variations in the metallicity dependence of AGB yields either worsen the agreement or show inconsistent effects across elements, while distributions of massive star rotational velocities with lower velocity at high metallicities fail to improve results due to balanced effects on different elements. Conclusions. The predictions of our model confirm, as expected, that there is no single relationship [s/α] versus age and that it varies along the MW disc. However, the current prescriptions for neutron-capture element yields are not able to fully capture the complexity of evolution, particularly in the inner disc.

Aims. Mrk 421 was in its most active state around early 2010, which led to the highest TeV gamma-ray flux ever recorded from any active galactic nuclei (AGN). We aim to characterize the multiwavelength behavior during this exceptional year for Mrk 421, and evaluate whether it is consistent with the picture derived with data from other less exceptional years. Methods. We investigated the period from November 5, 2009, (MJD 55140) until July 3, 2010, (MJD 55380) with extensive coverage from very-high-energy (VHE; E > 100 GeV) gamma rays to radio with MAGIC, VERITAS, Fermi-LAT, RXTE, Swift, GASP-WEBT, VLBA, and a variety of additional optical and radio telescopes. We characterized the variability by deriving fractional variabilities as well as power spectral densities (PSDs). In addition, we investigated images of the jet taken with VLBA and the correlation behavior among different energy bands. Results. Mrk 421 was in widely different states of activity throughout the campaign, ranging from a low-emission state to its highest VHE flux ever recorded. We find the strongest variability in X-rays and VHE gamma rays, and PSDs compatible with power-law functions with indices around 1.5. We observe strong correlations between X-rays and VHE gamma rays at zero time lag with varying characteristics depending on the exact energy band. We also report a marginally significant (∼3σ) positive correlation between high-energy (HE; E > 100 MeV) gamma rays and the ultraviolet band. We detected marginally significant (∼3σ) correlations between the HE and VHE gamma rays, and between HE gamma rays and the X-ray, that disappear when the large flare in February 2010 is excluded from the correlation study, hence indicating the exceptionality of this flaring event in comparison with the rest of the campaign. The 2010 violent activity of Mrk 421 also yielded the first ejection of features in the VLBA images of the jet of Mrk 421. Yet the large uncertainties in the ejection times of these unprecedented radio features prevent us from firmly associating them to the specific flares recorded during the 2010 campaign. We also show that the collected multi-instrument data are consistent with a scenario where the emission is dominated by two regions, a compact and extended zone, which could be considered as a simplified implementation of an energy-stratified jet as suggested by recent IXPE observations.

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 $\gamma \gamma, Z \gamma$ 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.

We develop a new approach to Vlasov Perturbation Theory (VPT) that solves for the hierarchy of cumulants of the phase-space distribution function to arbitrarily high truncation order in the context of cosmological structure formation driven by collisionless dark matter. We investigate the impact of higher cumulants on density and velocity power spectra as well as the bispectrum, and compare to scale-free $N$-body simulations. While there is a strong difference between truncation at the first cumulant, i.e. standard perturbation theory (SPT), and truncation at the second (i.e. including the velocity dispersion tensor), the third cumulant has a small quantitative impact and fourth and higher cumulants only have a minor effect on these summary statistics at weakly non-linear scales. We show that spurious exponential growth is absent in vector and tensor modes if scalar-mode constraints on the non-Gaussianity of the background distribution function that results from shell-crossing are satisfied, guaranteeing the screening of UV modes for all fluctuations of any type, as expected physically. We also show analytically that loop corrections to the power spectrum are finite within VPT for any initial power spectra consistent with hierarchical clustering, unlike SPT. Finally, we discuss the relation to and contrast our predictions with effective field theory (EFT), and discuss how the advantages of VPT and EFT approaches could be combined.

Worldline quantum field theory (WQFT) has proven itself a powerful tool for classical two-body scattering calculations in general relativity. In this paper we develop a new worldline action involving bosonic oscillators, which enables the use of the WQFT formalism to describe massive compact bodies to all orders in their spins. Inspired by bosonic string theory in the tensionless limit, we augment traditional trajectory variables with bosonic oscillators capturing the spin dependence. We show its equivalence to the covariant phase space description of a spinning body in curved space and clarify the role of the spin-supplementary condition in a Hamiltonian treatment. Higher-spin Hamiltonians are classified to linear and quadratic order in curvature. Finally, perturbative computations at 1PM order for arbitrary powers and orientations of spin and at 2PM up to quartic spin order are performed, recovering results from the literature.

We provide a framework for numerically computing the effects of free-streaming in scalar fields produced after inflation. First, we provide a detailed prescription for setting up initial conditions in the field. This prescription allows us to specify the power spectra of the fields (peaked on subhorizon length scales and without a homogeneous field mode), and importantly, also correctly reproduces the behaviour of density perturbations on large length scales consistent with superhorizon adiabatic perturbations. We then evolve the fields using a spatially inhomogeneous Klein-Gordon equation, including the effects of expansion and radiation-sourced metric perturbations. We show how gravity enhances, and how free streaming erases the initially adiabatic density perturbations of the field, revealing more of the underlying, non-evolving, white-noise isocurvature density contrast. Furthermore, we explore the effect of non-gravitational self-interactions of the field, including oscillon formation, on the suppression dynamics. As part of this paper, we make our code, Cosmic-Fields-Lite (CFL) , publicly available. For observationally accessible signatures, our work is particularly relevant for structure formation in light/ultralight dark matter fields.

The synthesis of life from non-living matter has captivated scientists for centuries. It is a grand challenge aimed at unraveling the fundamental principles of life and leveraging its unique features, such as resilience, sustainability, and the ability to evolve. Synthetic life holds immense potential in biotechnology, medicine, and materials science. Advancements in synthetic biology, systems chemistry, and biophysics have brought us closer to achieving this ambitious goal. Researchers have successfully assembled cellular components and synthesized biomimetic hardware for synthetic cells, while chemical reaction networks have demonstrated potential for Darwinian evolution. However, numerous challenges persist, including defining terminology and objectives, interdisciplinary collaboration, and addressing ethical aspects and public concerns. Our perspective offers a roadmap toward the engineering of life based on discussions during a two-week workshop with scientists from around the globe.

We report the application of the new elimination of Rutherford elastic scattering technique for the measurement of proton-induced reaction cross sections utilizing stored ions decelerated to astrophysical energies. This approach results in a background reduction factor of about 1 order of magnitude, enabling the first measurement of a (p,n) cross section in a storage ring. Here, the reaction channels 124Xe⁢(p,n) and 124Xe⁢(p,\gamma) have been studied just above the neutron threshold energy. The new data provide valuable constraints for Hauser-Feshbach theory and extrapolation of the (p,\gamma) cross section to lower energies. Most importantly, for nuclei of limited availability, the method represents a powerful improvement to efficiently study proton-induced reactions at energies within or close to the astrophysical Gamow window, bringing many reaction measurements within reach that were previously inaccessible in the laboratory.

Understanding the physics of planetary magma oceans has been the subject of growing efforts, in light of the increasing abundance of solar system samples and extrasolar surveys. A rocky planet harboring such an ocean is likely to interact tidally with its host star, planetary companions, or satellites. To date, however, models of the tidal response and heat generation of magma oceans have been restricted to the framework of weakly viscous solids, ignoring the dynamical fluid behavior of the ocean beyond a critical melt fraction. Here we provide a handy analytical model that accommodates this phase transition, allowing for a physical estimation of the tidal response of lava worlds. We apply the model in two settings: the tidal history of the early Earth–Moon system in the aftermath of the giant impact, and the tidal interplay between short-period exoplanets and their host stars. For the former, we show that the fluid behavior of the Earth's molten surface drives efficient early lunar recession to ~25 Earth radii within 10⁴–10⁵ yr, in contrast with earlier predictions. For close-in exoplanets, we report on how their molten surfaces significantly change their spin–orbit dynamics, allowing them to evade spin–orbit resonances and accelerating their track toward tidal synchronization from a gigayear to megayear timescale. Moreover, we reevaluate the energy budgets of detected close-in exoplanets, highlighting how the surface thermodynamics of these planets are likely controlled by enhanced, fluid-driven tidal heating, rather than vigorous insolation, and how this regime change substantially alters predictions for their surface temperatures.