IRAS 17449+2320 is the first identified magnetic B[e] star. It belongs to a subgroup of peculiar hot B-type stars, called FS~CMa stars. presenting the B[e] phenomenon, i.e., permitted and forbidden emission lines, and infrared excess as a result of the large amount of gas and dust surrounding the central star. The origin of this circumstellar material is unclear, with binarity being the most accepted scenario. However, the presence of a magnetic field in IRAS 17449+2320 points to the merger origin. In this paper, we confirm and characterize the magnetic field of this object, and constrain its rotation and binarity. We used a sample of 12 spectropolarimetric observations taken with ESPaDOnS at the CFHT. We obtained the least squares deconvolution (LSD) profile of the Stokes $V$ parameter of each spectropolarimetric observation. From the LSD profiles, we measured the longitudinal magnetic field (B$_z$), and obtained the magnetic field modulus ($|B|$) from the Zeeman splitting of some metallic lines of the spectra. We calculated a Lomb-Scargle periodogram over B$_z$ to obtain the rotational period of this star. B$_z$ presents a sinusoidal variation with a stable period of 36.11 days, with values ranging from 3000 G to -1000 G. $|B|$ measurements range from $\sim$4400~G to $\sim$6000~G, and it shows a second order term periodic variation. The stable sinusoidal variation of B$_z$ implies an approximately dipolar surface field topology. IRAS~17449+2320 is the first magnetic B[e] star detected. It presents Zeeman splitting in individual lines and consistent Stokes $V$ profiles. We see no evidence of binarity in this object, with stable radial velocities and no detectable lines of a secondary star in the spectrum. We consider the possibility that this star is the result of a merger, which could have generated the strong magnetic field and the large amount of circumstellar material.

Young compact clusters of massive stars contain dozens of O-, B- and WR-type stars with fast powerful winds in a small $\sim$ pc radius core. The particle acceleration by ensembles of shocks accompanied with long-wavelength compressions and rarefactions in the turbulent environment of young massive star clusters (YMSCs) is an alternative to the standard paradigm of Galactic cosmic ray acceleration on supernova shocks. In recent years, the topic has been of great interest due to the fact that modern gamma- and X-ray observatories have detected the radiation from YMSCs, which indicates particle acceleration processes in these objects. We study particle propagation and acceleration in a YMSC with the help of 3D magnetohydrodynamic (MHD) modeling using an open source PLUTO code. The code allows modeling of the turbulent environment of YMSCs and obtaining crucial for particle acceleration values of velocity, density, and magnetic field inside the cluster core. The Particle module implemented in PLUTO allows solving the equations of motion for test charged particles together with MHD equations for the medium. We obtained that protons acceleration up to hundreds of TeV takes place in the cluster core near the termination shocks of O-stars, which are surrounded by shocks of their neighbour stars. We also modeled an interesting case of a young supernova remnant expanding inside the cluster core. In this case a very fast acceleration takes place: particle energies $\gtrsim$ 100 TeV can be obtained in $\lesssim$ 100 years. The particle spectra and spatial distribution are discussed.

We use first-principles molecular dynamics simulations to study the deformation and breaking of neutron star crusts. When simulating with strain rates several orders of magnitude slower than prior work, we find a new regime of steady plastic flow beyond the breaking point that is independent of the initial crystal structure. Polycrystals exhibit a robust transition from linear elasticity to perfect plastic flow at shear strains of $ε= 0.05$, while monocrystals break at $ε= 0.11$ and then flow plastically. The universal post-break plasticity may arise because the crystal self-consistently assumes a defect density to accommodate the imposed strain rate. If broken crusts can re-anneal to large crystal sizes, crust breaking may repeat with implications for magnetar bursts and flares.

We investigate the causes of discrepancies in meridional-circulation measurements derived from the helioseismic observations by the Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory (SDO/HMI) and the Global Oscillation Network Group (GONG). Using contemporaneous Dopplergrams from both instruments that are processed consistently, we measure relative oscillatory phase shifts at identical solar locations and analyze north-south acoustic travel-time shifts on both sides of the solar central meridian. Our analysis reveals a persistent area of phase-shift anomalies in the northwestern quadrant of the solar disk, whose magnitude increases over the analysis period from 2010 through 2024. After removing the axisymmetric component, the phase-shift maps display a deceasing trend from the northeastern to the southwestern quadrant, which can be misinterpreted as flows in helioseismic analyses. The travel-time measurements also show significant inconsistencies on the eastern and western sides of the central meridian for both instruments, although a close agreement between both sides is expected. These findings indicate that both SDO/HMI and GONG carry systematic artifacts affecting meridional-circulation measurements, and that the time-varying phase anomalies and eastern-western asymmetry pose major challenges for their accurate characterization and correction.

Temperate sub-Neptune and terrestrial exoplanets could contain large inventories of water in various phases, such as water-dominated atmospheres or even oceans. Observations have shown that many exoplanets, including water worlds, likely contain photochemically-generated hazes. Haze particles are a key source of organic matter and may impact the evolution or origin of life; their optical properties are imperative for interpreting observations through theoretical atmospheric modeling. Modelers have thus far assumed haze optical properties that may not represent hazes under sub-Neptune and terrestrial atmospheric conditions. Often orbiting close to M-dwarf stars, these planets receive large amounts of radiation, especially during flaring events, which may accelerate atmospheric escape and affect atmospheric compositions. Here, we present optical constants of experimentally-generated sub-Neptune haze analogs before and after UV irradiation across a broad wavelength range (0.5 to 8 μm). We find that UV-irradiation alters haze optical constants which become generally more absorbing in this wavelength range, which we hypothesize is due to our sample containing more oxygen-rich absorbing bands post irradiation. We use Virga and PICASO to simulate transmission spectra of potentially hazy water-dominated planets GJ 1214b and LHS 1140b, accounting for irradiated haze layers in their atmospheres. For our GJ 1214b CH4-rich haze modeled case, we see a difference in the N-H feature at 2.6 μm in the resulting transmission spectrum between irradiated and unaltered haze that should be observable within current JWST capabilities. Broadly, we demonstrate the importance of using more representative optical constants, as they have an impact on current and future atmospheric composition interpretations.

We aim to quantify the star formation rate (SFR) from deep optical spectroscopic data and far-infrared (FIR) photometry from a sample of galaxies at $z\sim 0.9$ from the OTELO survey and compare the activity estimated by optical tracers and FIR emission. We used the multi-wavelength OTELO catalogue to construct a sample of FIR sources. We identified and separated galaxies with active nuclei and derived the physical properties of the rest. We analysed their spectral energy distribution, obtaining estimates for stellar mass, dust attenuation, luminosity, and SFR based on infrared luminosity. We also studied H$β$ and [OIII] emission-line galaxies without significant FIR emission from previous works. This approach allowed us to perform a comparative analysis among the SFR obtained through different calibrators, in particular H$β$, presented in a previous work. We find that FIR-based SFR estimates uncover a significant fraction of hidden star formation. We determined that the SFR density obtained from the FIR emission is three times larger than that obtained from only emission-line sources. Likely related to the fact that each SFR tracer provides insight into star formation over different timescales, we suggest that such indicators are also more or less suited for different galaxy populations. Specifically, while optical emission lines effectively trace star formation in lower-mass galaxies, FIR-derived SFRs provide a more reliable measure in massive dust-rich systems. By accounting for both optically visible and obscured star formation, we provide a more comprehensive view of the star-forming main sequence at $z \sim 0.9$ and reinforce the importance of infrared tracers in studying galaxy evolution.

The Centaurus cluster is one of the most important archetypes of radio-mode AGN feedback, with its central galaxy, NGC 4696, launching powerful jets that inflate X-ray cavities and regulate cooling and star formation. NGC 4696 lies within a spectacular multiphase nebula of filaments extending over tens of kiloparsecs and spanning six decades in temperature, from hot (10^8 K) X-ray-emitting plasma to cold molecular gas. Owing to its proximity, Hubble Space Telescope H_alpha imaging reveals a striking S-shaped ionized-gas swirl within the black hole's sphere of influence - the first such structure identified in a cluster core. Here we present the first JWST observations of NGC 4696 with NIRSpec, probing the inner 618 pc * 618 pc at 10 pc resolution. These data reveal that the ionized swirl is a rotating, multiphase circumnuclear disk (CND) physically and kinematically connected to the larger-scale filamentary network. This provides the long-sought missing link between kiloparsec-scale cooling flows and black hole accretion on <100 pc scales. Strikingly, the observed morphology and kinematics are reproduced by tailored magnetohydrodynamic simulations, in which filamentary gas condenses from the hot atmosphere, loses angular momentum, and feeds a rotating CND that mediates accretion onto the black hole. A similar structure in NGC 1275, the Perseus cluster's central galaxy, together with our results on NGC 4696 - two prototypical radio-mode AGN feedback systems - points to a common mechanism: multiphase filaments transport gas from cluster scales down to the vicinity of the black hole via a CND, closing the AGN feedback loop and establishing a physically grounded framework for self-regulated galaxy evolution.

Spectroscopic studies of ultra-faint dwarf galaxies are typically limited to small samples of stars due to the scarcity of sufficiently bright targets. The small number statistics and possible presence of contaminants still hamper solid determinations of their metallicity distribution function. In this work, we characterise the metallicity distributions of 12 Milky Way faint satellites by exploiting deep narrow-band CaHK photometry from the Pristine dwarf galaxy survey. In order to derive accurate stellar photometric metallicities, we combined it with deep broad-band g and r photometry from Muñoz et al. (2018) and Pan-STARRS1, covering each system out to 5-8 times their half-light radius Rh, and reaching magnitudes as faint as g~23. Membership probabilities were determined incorporating the available spatial, photometric, astrometric, and spectroscopic information, further refined using the derived photometric metallicities. We identified 3917 probable member stars across the 12 systems, more than doubling the numbers recovered by previous spectroscopic studies. We deliver complete metallicity distributions that yield robust average metallicities and dispersions previously inaccessible for most of the systems examined in this study. We identify 170 candidate extremely metal-poor stars distributed across all systems, and confirm a departure from the linear luminosity-metallicity relation in the ultra-faint regime, with systems scattering around [Fe/H]~-2.3 dex. Given the extensive mass coverage of our sample, we were able to investigate the presence of metallicity gradients, finding clear evidence of radial variations in massive systems, but none in the ultra-faint dwarfs within 2.5xRh. The photometric strategy presented in this paper will continue to serve as an effective complement to future spectroscopic surveys.

We present deep rest-ultraviolet (UV) spectra of six luminous $z=5$ -- 9 galaxies in the Abell-2744 field taken as part of the JWST Cycle 4 Large Program SPURS. The individual galaxy spectra show unambiguous detections of interstellar medium (ISM) metal absorption lines from low- and high-ionization states of enriched gas, which we use to probe the ISM gas porosity and kinematics. We find a striking diversity in the absorption profiles. We find low-ionization gas covering fractions ranging from 0.2 to 0.9, indicating a heterogeneous and patchy neutral ISM. The low-ionization kinematics also show a large diversity, with velocity centroid values ranging from $+$70 to a significantly blueshifted $-140$ km$\,$s$^{-1}$, while the high-ion gas shows mostly blueshifted absorption, indicating the presence of multiphase outflows. While all sources show outflow signatures in blueshifted wings, we also find that half of our sample, in particular those with the lowest stellar masses and highest sSFRs, have low-ionization velocity centroids close to systemic velocities. This is in contrast to near-ubiquitous bulk low-ionization gas outflows at lower redshifts. We suggest that this diversity of kinematics may be due to the bulk of the cold gas having low outflow velocities in the lowest mass and highest sSFR systems, potentially due to inefficient entrainment and/or an unresolved infalling component. These spectra reveal a metal-enriched ISM with complex gas geometry and kinematics, and highlight the potential of deep JWST grating spectroscopy to reveal the properties of the ISM during the reionization era.

Saturn's moon Titan is a unique environment in the solar system. It is the only moon with an atmosphere, composed primarily of the gases N2 and CH4. It is also the only world to have abundant surface hydrocarbons CxHy, which are found as both liquids (seas, lakes) and solids (dunes). Meanwhile, oxygen is also readily accessible in the form of crustal water. This combination of abundant reduced carbon, along with available nitrogen and oxygen makes Titan an enticing world rich in resources that can be readily used to make food, fuel, building materials and more - potentially mission-enabling for long-duration voyages or habitats in the outer solar system. At the same time Titan, as an icy moon, is likely to be depleted at the surface in heavier elements including metals, which must therefore be found and brought from elsewhere. In this article we describe both the available resources on Titan, and also their potential uses. We compare and contrast the resource availability and potential in-situ utilization (ISRU) with other destinations suggested for human habitation such as the Moon and Mars. We conclude by discussing what future work will be important to further characterize Titan's resources, and to develop technologies for their utilization.

We investigate the impact of mixed cold and fuzzy dark matter (MDM) cosmologies on the halo mass function (HMF) using numerical simulations performed with the AxiREPO framework. We consider models in which an ultralight axion-like component with mass $m =10^{-24.5} \mathrm{eV}$ constitutes a fraction $f \leq 0.3$ of the total dark matter. To enable consistent halo identification in mixed-species scenarios, we develop a grid-based halo-finding pipeline that combines the particle-based cold dark matter (CDM) and wave-like fuzzy dark matter (FDM) components into a unified density field. We find that FDM traces the large-scale CDM distribution while suppressing small-scale structure through wave interference effects, leading to a reduction in the abundance of low-mass haloes and modifying the HMF in a manner dependent on redshift and FDM fraction. Increasing the FDM fraction produces a systematic downward shift in the HMF and modifies its high-mass slope. Motivated by these trends, we introduce a phenomenological model that maps CDM HMFs to their MDM counterparts using a suppression function with parameters dependent on redshift and FDM fraction. This model reproduces the simulated HMFs within approximately 0.1 to 0.2 dex across the parameter space explored ($1 \leq z \leq 4$, $f \leq 0.3$). Our results provide a computationally efficient method for predicting structure formation in MDM cosmologies without requiring dedicated simulations for each parameter choice, and establish a framework for exploring the impact of MDM on cosmological structure formation.

The relative importance of intrinsic colour variability of supernovae type Ia (SN Ia) versus dust-induced reddening remains an open question with important ramifications for understanding their environmental dependence, as well as for the validity of the traditionally employed Tripp linear correction for cosmological inference. We revisit this question in the light of two low-redshift, homogeneous datasets, the ZTF DR2 and Foundation DR1, which we analyse within the framework of the Bayesian hierarchical model Simple-BayeSN. We demonstrate both with simulation and on real data that traditional colour cuts, which remove highly reddened samples, induce a previously unrecognized selection effect, which may have biased previous conclusions on the origin of SN Ia colour variability. Once this is accounted for, we are able to explain the entirety of the colour--magnitude correlation as due to dust effects, with no need for an intrinsic colour correlation. This result is robust with respect to a host galaxy mass split and projected distance from the center of the host. Our findings imply that the traditional linear Tripp correction maintains an empirical validity, even though it should be ascribed to dust rather than intrinsic colour variation.

The first components of a new meta-survey, the Combined Dense Gas and Excitation Atlas (CODEX) of the Milky Way, are presented here with combined data from five previously published surveys: NANTEN+CHaMP, ThrUMMS, FUGIN, and MWISP. The CODEX is first used to harmonise the combination of parameters used to describe the Galaxy's scale and rotation, including $R_0$ and $Θ_0$ from recent work, since these are critical components of standard techniques for obtaining kinematic distances. An additional feature is added to these formulae to accommodate local clouds that are otherwise kinematically inconsistent with the Local Standard of Rest. The structure in the combined lV diagram spanning 230 deg of longitude is then analysed, yielding a new Ragged Spiral Arm model that better traces the deprojected (x,y) 12CO structure. The widespread existence of ripples in the molecular layer, first reported in the ThrUMMS data of the Fourth Quadrant (4Q), is confirmed in FUGIN data of the First Quadrant (1Q), averaging amplitudes $\sim$40 and $\sim$23 pc respectively, and wavelength $\sim$4 kpc in both. The (x,y) mass distributions as traced by the molecular line data and the published dust extinction data match well across the 4Q+inner1Q, but poorly across the outer 1Q, probably due to lower sensitivity in the 1Q extinction data. In the 1Q+4Q, however, the two mean-z distributions do not match: the dust ripple amplitude is $\sim$3x smaller than, and opposite in sign to, the gas ripples. This is nevertheless consistent since the dust extinction is insensitive to the densest molecular gas.

The NIRCam medium-bands have proven to be efficient at identifying Emission Line Galaxies (ELGs) with high equivalent width (EW) H$α$ and [OIII]+H$β$ emission lines. In this paper we exploit this efficiency to identify a sample of ELGs at $4.9 \lesssim z \lesssim 8.9$ using medium-band imaging from the CANUCS, Technicolor, and JUMPS surveys. We find that the ELGs exhibit a strong correlation between continuum color and emission line strength, such that galaxies with bluer UV/optical continua have stronger H$α$ and [OIII]+H$β$ emission lines. We identify 26 galaxies that are outliers from this relation, which we call the Red Emission line Galaxies (REGs), because of their red continuum color and strong emission lines. We classify the REGs into three categories: 1) ''classic'' Little Red Dots (LRDs) selected with common literature criteria, 2) extended REGs, resolved in F444W and consistent with being Dusty Star Forming Galaxies (DSFGs), and 3) compact REGs, unresolved in F444W but not classified as LRDs. The compact REGs fail common LRD selections for several reasons, including faint continuua, contamination from emission lines (very strong [OIII]+H$β$), and UV/optical colors that are flatter than those of LRDs. We conclude that the compact REGs are likely LRDs that ''classic'' selection criteria miss, and are therefore missing from existing samples. Our results suggest that medium-band selection can provide more complete samples of these objects.

Boosting the Hubble Space Telescope (HST) will provide unique opportunities to carry out precursor science for the Habitable Worlds Observatory (HWO). Chief among them are science cases for determining the properties of star forming galaxies that contribute to creating and sustaining the universe in a mostly ionized state. The farUV and nearUV spectroscopic capabilities of the Cosmic Origins Spectrograph (COS) and the Space Telescope Imaging Spectrograph (STIS) are unique and unlikely to be replicated in the near future. Here we describe the benefits of a deep panchromatic spectroscopic effort to answer questions concerning the shape of the rest frame ionizing radiation escaping from star forming galaxies at modest redshift, capture crucial missing spectral regions, and explore whether their star formation histories are truly similar to the LyC leakers responsible for initiating and later sustaining the mostly-ionized-state of the universe. An observing program emphasizing multi-orbit observations, unencumbered by HST orbit competition and freely accessible to the wider ionizing photon (iPhoton) community, will catalyze crowd-sourced answers to these questions and offer a lower operating cost price point.

Recurrent tidal disruption events (rTDEs) are sources that exhibit multiple TDE-like flares; many are likely powered by the recurring partial disruption of a bound star, in a repeating partial TDE (rpTDE). Two such sources, TDE 2022dbl (ASASSN-22ci) and TDE 2020vdq (ZTF20acaazkt), each exhibited two UV/optical flares and, under the assumption of periodicity, both were expected to exhibit a third flare in early 2026. Neither exhibited such a flare, to limits of $L_{\textrm{UV/optical}} \lesssim 10^{42}$ erg s$^{-1}$, $\sim$30$\times$ fainter than the previous flares. Here, we examine several possible explanations. Observing two independent TDEs from the same galaxy within $\sim$2 yr has a probability of $\lesssim$0.5% for measured average TDE rates and currently expected rate enhancements, unless there is extreme intrinsic dispersion in the rates. Theoretical predictions for a double TDE of both stars in a binary are inconsistent with the observed flares. We therefore conclude that TDE 2022dbl and TDE 2020vdq are rpTDEs. To produce only two observable flares with similar energetics, our semi-analytical modeling strongly favors a main-sequence star promptly placed on a bound orbit with a deep initial tidal encounter at pericenter. These results suggest that the majority of rTDEs with multiple flares over a few-year baseline are likely to be rpTDEs, and that a significant fraction of systems may produce only two observable flares. This has important implications for the use of r(p)TDEs as probes of TDE physics and dynamical processes in the nuclei of other galaxies, in addition to the expected yield from upcoming surveys.

Magnetic reconnection powers solar and stellar flares, but a full understanding of how the released energy is transported and converted within the solar atmosphere remains elusive. One clue lies at solar-flare footpoints, where spectral lines are far broader than the electron temperature alone can explain. Unresolved flows, waves, turbulence and ion heating have all been proposed, but observations have not yet conclusively distinguished between these mechanisms. Here we perform an unprecedented geometric test for flare footpoints, using 4,593 Hinode/EIS spectra from 407 C- to M-class flares. Line widths decrease systematically from disk centre to limb in all coronal emission lines, showing that the dominant broadening component is magnetic field aligned rather than isotropic or transverse. Cooler lines retain substantial broadening into the early decay phase, consistent with persistent unresolved field-aligned flows or line-of-sight velocity gradients. Hotter lines show an impulsive component that decays rapidly after the soft X-ray peak, consistent with preferential ion heating and ion temperature anisotropy. These findings resolve the long-standing question of the nature of line broadening at flare footpoints, place direct limits on flare energetics, and motivate a new direction in flare physics incorporating distinct field-aligned and perpendicular ion temperatures that exceed the electron temperature.

(Abridged) Little Red Dots (LRDs) are a class of sources discovered by JWST observationally defined by a "V-shaped" rest-frame UV-Optical SED, a compact or unresolved morphology, and for having, frequently, broad hydrogen emission lines. Among various models, those involving a quasi-star interpret LRDs as an intermediate stage in the evolution of a super-massive black hole (SMBH) seed into a classic AGN. In this paper, we employ the radiative-transfer code \texttt{Cloudy} to study whether this model is able to reproduce the spectral features commonly observed in LRDs. The model consists of an accreting SMBH ($M_{\rm BH}\sim10^{5-6} \ M_\odot$) surrounded by a convective layer where a black-body (BB) spectrum with $T\sim5000 \ {\rm K}$ and $L\sim10^{44.4} \ {\rm erg \ s}^{-1}$ is produced. This BB is then reprocessed by a concentric thick ($ΔR\sim1000 \ {\rm AU}$) shell of dense ($n_{\rm H}\sim10^{11} \ {\rm cm}^{-3}$) gas partially ionised by thermal collisions. The emerging radiation is further reprocessed by a diffuse clumpy medium surrounding the quasi-star. We fit this model to JWST/NIRSpec spectra of LRDs from the literature, deriving the main physical parameters and the SMBH masses. Once coupled with the UV emission from a host galaxy, this model is able to reproduce the shape of the UV-to-NIR continuum, including the presence of a Balmer break, as well as the luminosity of the hydrogen emission lines. However, this quasi-star model does not natively account for the presence of broad helium lines and for the possible presence of hot dust, needing additional components to match these observables. Our main result is to show how some LRDs can be modeled as quasi-stars, highlighting that a significant degeneracy exists among different LRD models. This has important consequences for our understanding of the mechanisms driving black hole growth in the early Universe.

GW190521 and GW231123 have been reported as short-duration gravitational-wave transients consistent with very massive binary black hole (BBH) coalescences whose inferred parameters, i.e., exceptionally high total masses and spin magnitudes, challenge standard isolated binary stellar evolution. We test a topological dark matter (TDM) interpretation invoking cosmic domain walls by fitting a physically motivated domain wall template to the LIGO Hanford and Livingston strain data. The BBH hypothesis is individually favored, with $\log_{10}\mathcal{B}_{\rm BBH/TDM}=12.2$ and $11.3$ for GW231123 and GW190521, respectively. However, these values are lower than those typically recovered from matched maximum a posteriori BBH waveforms injected into nearby noise segments. We further perform, for the first time, a joint fit in which domain wall signals from a single underlying scalar field are constrained simultaneously by both events. Although not favored over BBH signals, we find the two events are consistent with a common scalar field, with shared TDM parameters agreeing across independent noise realizations and sky locations. We further find that injected TDM transients are systematically recovered under the BBH hypothesis with large spin parameters, revealing a morphological degeneracy that could mask genuine domain wall signals. This analysis demonstrates that multi-event parameter consistency tests provide a new discriminant for domain wall dark matter searches in upcoming observing runs.

The $B_s^0\to K_S K^\pm π^\mp$ decays are of interest to test the Standard Model and search for new sources of $CP$ violation. A full study of these decays requires a tagged decay-time-dependent Dalitz-plot analysis performed simultaneously in the two final states. Such an analysis has never previously been performed. The method to carry out such an analysis, relating the amplitudes for decays to resonances in the two final-states to each other, is set out and its feasibility is demonstrated using pseudoexperiments. The sensitivity to the weak phase difference, $ϕ_s^{\rm eff}$, between $B_s^0 \to K_S K^*(892)^0$ decays with and without $B_s^0$-$\bar{B}_s^0$ mixing is studied. Good precision on $ϕ_s^{\rm eff}$ is found to be achievable with a dataset corresponding to LHCb Runs 1-3, with further improvement expected with datasets to be collected in future. The method is implemented in the Laura++ Dalitz-plot analysis package, and can be applied to other multibody decays with multiple final states.

Recent innovation theories on economics remain largely grounded in assumptions of hierarchical firms and closed organizational boundaries, offering limited insight into how innovation unfolds within decentralized, digitally native organizations. Decentralized Autonomous Organizations (DAOs) represent an emerging form of innovation ecosystem characterized by blockchain-based transparency, open participation, and token-driven governance, in which sustainability can be embedded directly into organizational design. This study compares two standards, ERC-8004 and Google A2A, who address the same agent interoperability question, while the former is governed by DAO and the latter by corporation consortium. They are examined through an LLM-powered comparative pipeline for large-scale governance discourse analysis, integrating automated annotation, neural topic modeling, and multi-layer network analysis to study socio-technical power structures. The study provides evidence-based insights for scholars, policymakers, and designers seeking to align innovation, technological governance, and sustainability in future organizational forms.

We consider Higgs-boson pair production in gluon fusion at hadron colliders and match next-to-next-to-leading-order (NNLO) QCD corrections to parton showers within the MiNNLO$_{PS}$ framework. Since the full top-quark mass dependence at this order is not available, finite top-quark mass effects are incorporated through approximations based on the exact NLO QCD result, using the available two-loop amplitude in the full theory. Specifically, the Born, single-virtual, single-real and double-real contributions are included exactly, while the real--virtual and double-virtual corrections are approximated. We consider different approximations for the latter to assess the associated uncertainties. We validate our predictions against fixed-order NNLO QCD results and compare with existing NNLO calculations matched to parton shower from GENEVA, where in some cases we find noticeable differences. Finally, we present phenomenological results for different Higgs-decay channels and variations of the trilinear Higgs coupling. Our MiNNLO$_{PS}$ generator for Higgs-boson pair production is available within the POWHEG-BOX-RES framework.

The spin dynamics of water ice in the presence of external magnetic fields are investigated. The employed model builds upon the approach introduced by Buntkowsky et al. [Z. Phys. Chem. 222, 1049 (2008)], which considers two nearest-neighbor water molecules and yields a four-spin system, as the abundant oxygen isotope has zero nuclear spin. The model is extended to include coupling to external magnetic fields, allowing us to analyze the interplay between magnetic dipole-dipole interactions and magnetic field coupling. Two types of configurations are examined: (i) static, homogeneous fields, corresponding to a time-independent interaction, and (ii) spatially varying sinusoidal fields in relative motion with the molecules, leading to a time-dependent interaction. All computations are performed within the density operator formalism. The ortho/para populations and the total spin projections are evaluated during the first tens of milliseconds following the gas-to-solid phase transition. For static homogeneous fields, we show that increasing field strength suppresses dipolar-induced depolarization. Assuming that all molecules are initially in the para state, we show that static homogeneous fields can drive the ortho population up to approximately $50\%$, whereas suitably chosen sinusoidal-field configurations can increase it beyond $90\%$. These results are relevant for schemes aiming to preserve or manipulate nuclear-spin polarization during deposition.

The causal propagator (or Pauli-Jordan function), which multiplied by $i$ is the spacetime commutator of the field $[ϕ(x),ϕ(x')]$, plays an essential role in scalar quantum field theory. We discuss the role of the causal propagator and its spectrum in recent developments in defining quantum field theory in a more explicitly covariant manner, as well as in causal set theory. We then present a conjecture for its asymptotic spectral density in a free theory, and give examples that lend evidence to the conjectured scaling. Our work has implications for Lorentzian spectral geometry in much the same way as Weyl's asymptotic law has for Riemannian spectral geometry.

We study the Compton-rocket effect of strong radiation force accelerating electrons in an opaque fireshell (or fire spot) of dense photons and electron-positron pairs, whose temperature is spatially inhomogeneous and exceeds the electron mass. We find the possibility of the charged-particle acceleration and the avalanche runaway process, leading to a non-trivial probability of ultra-high-energy (UHE) electrons and protons, which subsequently produce very-high-energy (VHE) photons and neutrinos. In a simplified one-dimensional model, we qualitatively show such peculiar dynamics using the fireball, Gamma-Ray Burst central engine, whose inner part inflows and forms a gravitationally trapped fireshell (halo) around the horizon of a black hole. The fireshell is metastable, cooling via UHE particle emissions and blackbody radiation. We calculate the UHE particle luminosity varying in time, and discuss the peculiar features of such produced UHE particles, which lead to VHE particles, in connection with possible numerical simulations, observations and experiments.

In this paper, we consider the upper and lower bounds of the lifespan of classical solutions of the Cauchy problem for the one-dimensional quasilinear wave equation $u_{tt}-c(u_x)^2u_{xx}=0$ where the derivative of $c(θ)$ tends to $0$ near the origin. In particular, our result shows that the lifespan of the solution extends algebraically depending on the smallness of the initial data. Furthermore, we also show that when $c(θ)$ is flat at the origin ($c'(θ)$ and any higher order derivatives vanish at the origin), the lifespan extends exponentially depending on the smallness of the initial data. Our proof is based on the method of Lax's characteristics and Riemann invariants.

We introduce the degree filtration on the discrete cubical chain complex of a graph, defined in terms of the maximal injective dimension of the facets of singular $n$-cubes, and study the degree spectral sequence which arises from this filtration. This spectral sequence interpolates between the discrete cubical homology of a graph $H_n(G)$ and the injective homology $H_n^{inj}(G)$, a variant of the discrete cubical homology based on injective singular cubes. Building on the work of Babson et al. we introduce the combinatorial condition of quasimonophobicity on graphs, and show quasimonophobicity implies both the vanishing of the degree spectral sequence in certain bidegrees, and implies $H_n^{inj}(G)$ is isomorphic to the homology of the CW complex obtained by ``filling in'' subcubes of the graph. These results are applied to compute $H_2(G_n^{sph})$ for the Greene sphere graphs $G^{sph}_n$.

In this article we study the normal bundle and the deformation to the normal cone functors to get deformation Lie groupoids that allow us to construct pushforward maps in any suitable (co)homology theory for Lie groupoids (not only K-theory) and in a natural and geometric way. The main theorems being the functoriality for these pushforward maps which recovers, unifies and generalizes many previous cases. The main new example we develop in this paper is the wrong way functoriality for equivariant (twisted) Orbifold K-theory with respect to a groupoid action.

This article opens new window to obtain accelerating scaling attractors without any need of dark energy. We study cosmological dynamics in a two-fluid system where pressureless dark matter (DM) undergoes adiabatic particle creation and exchanges energy with a barotropic fluid. Considering six widely used interaction prescriptions, we formulate the corresponding autonomous systems in a compact phase space and perform a unified dynamical analysis. We find that accelerating scaling attractors, namely late-time states where both fluids coexist with fixed energy fractions, arise only when the interaction is controlled by the DM density and energy flows from DM to the second fluid. Such attractors appear in the global and local DM-based interactions, and in the global mixed case, but are entirely absent when the interaction depends on the second fluid or on local mixed terms, which instead drive the universe to a DM-dominated accelerating phase. These results clarify the unique conditions under which matter creation can mimic dark-energy-like behaviour without introducing a dark-energy component.

We study the Hoeffding regime of composite quantum hypothesis testing, in which each hypothesis is specified by a sequence of sets of quantum states. We establish quantum Hoeffding bounds under a set of structural assumptions, orthogonal to those of our previous framework. A notable consequence is the direct operational interpretation of the reverse sandwiched Renyi divergence for $α\in (0,1)$: for the task of discriminating a thermal equilibrium state from a probe state subject to unknown dephasing in the energy eigenbasis, with free Hamiltonian evolution as a special case, the optimal Hoeffding exponent is given exactly by this divergence evaluated on a single copy of the system. The same task in the Stein regime is governed by the reverse quantum relative entropy, providing its operational interpretation as well. This behavior contrasts both with the simple independent and identically distributed (i.i.d.) setting, where the Petz Renyi divergence and the Umegaki relative entropy govern the Hoeffding and Stein exponents, respectively, and with many composite settings, where only regularized many-copy formulas are available. This finding reveals that passing from simple to composite hypotheses can fundamentally change which quantum divergence determines the operational limits of discrimination, and suggests a new avenue for seeking operational interpretations of quantum divergences by lifting simple hypotheses to richer composite scenarios.