High Energy Physics (Phenomenology)
The $Z'$-boson of the $B-L$ Supersymmetric Standard Model and its Large Hadron Collider Searches
Waleed Abdallah, AseshKrishna Datta and Stefano Moretti
We discuss how the $Z'$-
boson of the $B-L$ Supersymmetric (SUSY) Standard Model (BLSSM) could evade the current lower bound of around 5 TeV on the mass of such a resonance (of sequential nature) from the Large
Hadron Collider (LHC) by a significant margin. This happens when the experimental sensitivities are critically impaired as the $Z'$-
boson becomes `fat' or develops some leptophobia or possesses an optimally large decay Branching Ratio (BR) to BLSSM-specific states (including the SUSY ones) or when some or all of these are at play simultaneously. We describe how such a $Z'$-
boson could acquire there features while still respecting the non-negotiable precision constraints from the LEP and the SLC experiments running at the $Z$-pole as well as those from the multi-purpose experiments at the LHC that search for such a resonance. We explore the interplay of the aforementioned phenomena and identify the regions of the BLSSM parameter space that give rise to the described situation by carrying out a thorough scan of it. We find that $M_{Z'}$ masses as low as 2.24 TeV may still be allowed in the BLSSM under favorable circumstances.
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General Relativity and Quantum Cosmology
A Potential Black Hole Mimicker From Non-Minimal Coupling
Debanjan Debnath, Rikpratik Sengupta and Kaushik Bhattacharya
We present a class of horizonless, regular ultra-compact objects arising in a theory of
gravity that allows
curvature-fluid coupling. The non-minimal interaction between fluid variables and the
Ricci scalar generates a
vacuum-like equation of state in the interior, while the exterior remains exactly Schwarzschild. The two spacetimes are glued through a thin shell at the junction. The interior metric is non-singular, the shell acquires a stiff-matter equation of state, and near-horizon compactness allows the configuration to mimic black-hole phenomenology without an event horizon. For radii in the astrophysically motivated range $5$–$7$ km, imposed as an external input rather than predicted by the theory, the model's mass-compactness relation maps this radius window onto a mass window of $1.4$-$2.1 M_\odot$ for a suitable choice of the
curvature-fluid coupling coefficient. We carry out a detailed stability analysis of the shell in the frozen-bulk approximation, identify the compactness window in which the interior is everywhere regular and the shell is stable, and quantify the accuracy of the frozen-bulk approximation through an explicit adiabaticity parameter. We then develop the surface thermodynamics of the shell assuming a first order phase transition-like origin of the ultra-compact object. This idea then gives rise to shell temperature and radiation, the shell temperature scaling $T_\Sigma \propto M^{-1/2}$ turns out to be a falsifiable predictions of the model.
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Quantum Gases
On operator product expansion in the spin-orbit coupled bosonic system
Rajesh Kumar Gupta and Siddhant Tiwari
Ultra-cold bosonic systems can be tuned to exhibit
quantum phase transitions. For example, the Rabi-coupled bosonic system exhibits
ferromagnetic and paramagnetic phases, whereas the
spin-orbit-coupled system exhibits exciting phases such as supersolidity. The physics of these phases and phase transitions is very rich. It is an important topic of research to probe these phases and phase transitions using various tools in many-body physics. The operator product expansion (OPE) provides one such tool. It expresses the product of two separated operators as a series expansion of local operators. In this article, we will derive the OPE of two operators $\psi^\dagger_\sigma(\vec r)$ and $\psi_{\sigma'}(\vec r')$. More specifically, we look for the contact density term, which controls many of the universal physics of the underlying bosonic system.
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Atomic Physics
Suppression of ionization stabilization in a driven Morse-Soft-Coulomb system
Murilo D. Forlevesi, Emanuel Fernandes de Lima and Gabriel Albertin Amici
Ionization stabilization is a well-known phenomenon in strongly driven Soft-Coulomb atomic models, where the ionization probability decrease as the field amplitude increases. In this work, we investigate how this process is affected by introducing a repulsive Morse barrier into the binding potential, leading to the Morse-Soft-Coulomb (MsC) model. A systematic comparison between the Soft-Coulomb and Morse-Soft-Coulomb systems is performed for different values of the softening parameter. Ionization probabilities, escape-time and Lagrangian descriptor maps reveal that the stabilization observed in the Soft-Coulomb model is suppressed in the Morse-Soft-Coulomb system. To elucidate the origin of this behavior, we analyze the corresponding Kramers-Henneberger effective potentials. While the Soft-Coulomb model develops a symmetric double-well structure supporting a large trapping region, the Morse-Soft-Coulomb potential exhibits a single effective minimum with a significative smaller trapping region. Our result indicate that the repulsive barrier leads to the suppression of the ionization stabilization.
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Astrophysics of Galaxies
Direct Tests of Black Hole Accretion Rate Prescriptions: I. Bondi Accretion at Different Scales
James Agostino, Ming-Yi Lin, Natasha Jones et al. (+9 more)
We present spatially resolved parsec-scale measurements of
nuclear conditions (gas density and kinetic temperature) relevant for black hole
accretion rate predictions in the Seyfert 2
galaxy, NGC 1068. We inject these parameters into the prescription for a Bondi-like
accretion model, then compare the resulting
accretion rate prediction to the empirical
accretion rate derived from hard X-ray observations. Cosmological simulations have spatial resolution ranging from $\sim$10 pc to $\sim$kpc scales, and so for reasonable comparison we test these
accretion rate predictions in pixel-sized radial steps out to 500 pc. Compared to warm H$_2$ gas, CO gas is the dominant mass carrier close to the SMBH. We find that the Bondi
accretion rate ($\dot{\mathrm{M}}_{\mathrm{Bondi}}$) of cold molecular gas alone (measured using CO) overestimates the true
accretion rate by up to 14 dex in a small aperture (r$\lesssim$5 pc) around the black hole, and by at least 8 dex inside large apertures (r$\lesssim$500 pc). These results are the first in a series of direct tests of
accretion rate prescriptions, and they suggest that using a Bondi
accretion formalism to model supermassive black hole
accretion in Seyfert 2
galaxies may lead to overestimated
accretion rates in simulations.
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All authors James Agostino, Ming-Yi Lin, Natasha Jones, Anne M. Medling, Loreto Barcos-Muñoz, Daniel Anglés-Alcázar, Claudio Ricci, George C. Privon, Vivian U, Paul Torrey, Philip F. Hopkins, Claire Max
High Energy Physics (Theory)
A Dispersive Bootstrap for the Virasoro-Shapiro Amplitude
Yongjun Xu
We study the closed-string tree-level Virasoro-Shapiro amplitude using the dispersive S-
matrix bootstrap. For the ten-dimensional maximally supersymmetric four-point amplitude, we impose analyticity, crossing
symmetry, partial-wave unitarity, and Regge boundedness. With the massless graviton pole kept explicitly, the resulting dispersion relations and crossing null constraints give numerical bounds on the leading low-energy coefficients normalized by the gravitational coupling, which agree at our reference truncation with earlier bounds from smeared functionals. We then introduce a Virasoro-inspired ansatz, which becomes a set of nonlinear relations among Wilson coefficients and shrinks the allowed region toward the Virasoro-Shapiro trajectory. Finally, we study a
gravity-pole-subtracted setup, where the regular part of the amplitude has a well-defined forward limit. In this stripped problem, on the slice of the leading coefficient that places the first Virasoro-Shapiro resonance at the cutoff, the nonlinear constraints reduce the allowed region to a small island containing the Virasoro-Shapiro point. Imposing the ansatz to all orders, together with spectral assumptions not used in the numerics, we show analytically that positivity selects the Virasoro-Shapiro spectrum.
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Astrophysics of Galaxies
The first detection of dense gas in a massive main-sequence galaxy at cosmic noon
Jianhang Chen, Natascha M. Förster Schreiber, Rodrigo Herrera Camus et al. (+18 more)
Dense gas is the direct fuel for
star formation, but measuring it has long been difficult at z>2, especially in typical
star-forming main-sequence
galaxies. In this work, we report the first detection of HNC (J = 5–4) and CN (N = 4–3) emission in a massive main-sequence
galaxy, BX610, at z=2.21. The velocity integrated emission of HNC(5–4)+CN(4–3) is concentrated in the
galactic centre, coincident with the region of ongoing intense
star formation. Based on line decomposition, we measure a line flux ratio HNC(5–4)/CN(4–3) of $1.05\pm0.23$, similar to that of starburst
galaxies at comparable
redshifts but lower than that of
quasar/AGN host
galaxies. The comparatively fainter HNC(5–4) disfavours the presence of a strongly buried AGN in BX610, consistent with optical line diagnostics. The radiative transfer analysis favours the presence of dense gas with a density of $(2-4)\times10^{6}\,\text{cm}^{-3}$ and a kinetic temperature of 50-80 K. The derived abundance ratio between N(HNC) and N(CN) favours dense gas clouds near photodissociation regions, as commonly seen in typical starburst environments. The inferred dense-gas line luminosity closely follows the scaling relation between far-IR and dense-gas line luminosities established for local luminous infrared
galaxies (LIRGs). Our observations support the view that
star formation in
cosmic noon
galaxies is primarily controlled by the availability of dense gas, which could be enhanced in central
galactic regions with efficient cold gas inflows as observed in BX610 along the inner spiral arms and a possible
stellar bar.
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All authors Jianhang Chen, Natascha M. Förster Schreiber, Rodrigo Herrera Camus, Lilian L. Lee, Minju M. Lee, Claudia Pulsoni, Daizhong Liu, Sebastián Arriagada-Neira, Capucine Barfety, Ric Davies, Frank Eisenhauer, Juan Manuel Espejo Salcedo, Reinhard Genzel, Jean-Baptiste Jolly, Dieter Lutz, Giovanni Mazzolari, Stavros Pastras, Alvio Renzini, Linda Tacconi, Giulia Tozzi, Hannah Übler
High Energy Physics (Theory)
Universal Closed Form for Dynamical Love Numbers of Black Holes
Mikhail P. Solon
Black hole static Love numbers vanish, but their dynamical counterparts do not. We present the entire scheme-independent dynamical response $\bar{F}_{\ell,s}$ of a Schwarzschild black hole in closed form, to all orders in $G$, and for every
spin $s$ and multipole $\ell$. The result is $\bar{F}_{\ell,s}/4\pi R_S^{2\ell+1}=\Phi_{\ell,s}(\bar{y})-\tfrac12\eta\,\Phi_{\ell,s}'(\bar{y})$ with $\bar{y}=-\tfrac12\eta^2\tau$ and $\eta=i\omega R_S$. Here $\Phi_{\ell,s}$ is simply the leading-log solution to the renormalization group equation, but lifting the running logarithm to $\tau=\log(R_S/R)-2\sum_{k\ge2}\zeta_k\,\eta^{k-1}$ resums it to all orders. This tower of Riemann
zeta values is the Newtonian phase in disguise: it originates from the long-range $1/r$ potential in the far zone, and is universal across multipole and
spin. Our result exhibits a factorization pinned to three ingredients: the strength of horizon absorption, the running rate in the near zone, and the dressed logarithm in the far zone. Using shell effective field theory, we independently verify our formula for scalar, electromagnetic, and gravitational perturbations, reaching $\mathcal O(G^{15})$.
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High Energy Astrophysical Phenomena
Improved proper motion and gravity tests with PSR J1913+1102
Xueli Miao, Paulo C. C. Freire, Norbert Wex et al. (+11 more)
PSR J1913+1102 is a highly asymmetric double
neutron star system and an excellent laboratory for testing scalar-tensor
gravity theories, as well as a potential progenitor analogue of GW170817 that will merge in 470 Myr. We present an updated timing analysis combining 13 years of historical Arecibo observations and new FAST measurements, using two approaches to model dispersion-measure variations. The new timing solution provides precise measurements of four post-Keplerian parameters and improves the system mass estimates. Assuming general relativity and modelling the DM variation with a Gaussian process, we obtain a three-fold improvement in the total mass, m_{tot}=2.88948(20) M_\odot, and nearly four-fold improvements in the
pulsar and companion masses, m_p=1.599(8) M_\odot and m_c=1.290(8) M_\odot, giving the mass ratio, q=0.807(8). We also measure an improved proper motion, \mu=7.71(25) mas yr^{-1}, enabling a more accurate correction of the observed orbital-period derivative. Combined with the improved orbital-decay measurement, this yields an intrinsic orbital-period derivative \dot{P}_b^{intr}=-4.60(6)\times10^{-13} s s^{-1}, five times more precise than the previous value and fully consistent with the general-relativistic prediction for gravitational-wave damping. The improved masses and precise \dot{P}*b^{intr} place stringent constraints on dipolar gravitational-wave emission and the spontaneous-scalarisation window around 1.6 M*\odot. The refined proper motion and mass measurements also provide tighter constraints on the final helium-
star mass immediately prior to its core collapse and formation of the second NS in a
supernova, as well as on the magnitude and direction of the associated natal kick of the DNS system.
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All authors Xueli Miao, Paulo C. C. Freire, Norbert Wex, Lingqi Meng, Thomas M. Tauris, Junjie Zhao, Weiwei Zhu, Robert Ferdman, Michael Kramer, Huanchen Hu, Lijing Shao, Yanjun Guo, David J. Champion, Youling Yue
Mesoscale and Nanoscale Physics
Theory of nonlinear spin transport in chiral conductors
Lorenzo Cavicchi and Marco Polini
The chirality-induced
spin selectivity (CISS) effect, discovered by Naaman and collaborators in 1999, describes the emergence of a finite
spin polarization in response to current flow through a
chiral electronic system. While extensive experimental studies have verified the presence of CISS in molecular systems and, more recently, in
chiral materials, a complete microscopic understanding of this effect remains elusive. In this work, we propose a theoretical framework linking the CISS effect to the orbital Edelstein effect. In the latter, a drive current induces a finite orbital magnetization, even in the absence of
spin-orbit coupling. Our non-
equilibrium theory naturally explains key features of the CISS effect: its persistence in systems with weak or vanishingly small
spin-orbit coupling and its connection to natural optical activity, a distinctive signature of
chiral systems.
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Quantum Physics
Random-matrix reduction in projective quantum mechanics: Numerical simulations
Alexey A. Kryukov
We present numerical simulations supporting the random-
matrix state-reduction framework developed in the companion theoretical paper. The simulations test the main derived features of the model: isotropic
diffusion generated by Gaussian
Unitary Ensemble
Hamiltonians in projective state space, the restriction of this
diffusion to Brownian motion on the classical submanifold, Born-rule frequencies for detector-defined outcome classes, and stroboscopic Newtonian motion for macroscopic systems under repeated environmental monitoring. We also compare GUE and GOE random
Hamiltonians and show that GOE fails to produce the required isotropic complex projective
diffusion. Further simulations examine finite-resolution detector records in the double-slit experiment, Zeno stability of recorded equivalence classes, effective irreversibility from high-dimensional state-space dynamics and loss of path information, and tensor-product particle-device dynamics in the device limit. The results show that microscopic state reduction, stable measurement records, effective irreversibility, and macroscopic classicality can be described as different coarse-grained manifestations of the same
stochastic unitary mechanism.
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Quantum Physics
Random-matrix reduction in projective quantum mechanics
Alexey A. Kryukov
We develop a state-space
geometric framework for measurement, classicality, and
quantum paradoxes, based on one dynamical
conjecture. Classical configuration space and classical phase space for a mechanical system arise as distinguished submanifolds of projective
quantum state space. On these submanifolds, the Fubini–Study geometry induces Euclidean classical geometry, and the tangent component of Schrödinger
evolution reproduces Newtonian dynamics. Within this framework, interactions with measuring devices and environments are described by random-
matrix dynamics on projective state space, generated by
matrices drawn from the Gaussian
Unitary Ensemble. We show that this random-
matrix dynamics yields isotropic
diffusion, giving Born-rule transition probabilities in microscopic measurements and stabilizing classical behavior in macroscopic systems. We further argue that the random-
matrix conjecture is not an independent ad hoc assumption: under natural translation-invariance assumptions on the distribution of state-space steps originating on the classical submanifold, the
unitary lift of homogeneous and isotropic Brownian motion on that submanifold is uniquely given by the Gaussian
Unitary Ensemble, up to scale and an irrelevant scalar part. The resulting framework provides a
unitary account of measurement and the
quantum-to-classical transition and, if accepted, offers a dynamical resolution of standard
quantum paradoxes.
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Medical Physics · Cross-listed from eess.IV
Beyond Algorithms: Conceptual Innovation in Medical Imaging AI
Mark A. Anastasio
Artificial intelligence has driven rapid progress in medical imaging research, producing increasingly sophisticated
algorithms and steady improvements on
benchmark tasks. However, this
algorithm-centric trajectory has also revealed a growing imbalance: while computational methods advance rapidly, the conceptual foundations that define imaging tasks, evaluation metrics, and clinical meaning sometimes remain underexamined. In this Perspective, we distinguish algorithmic innovation, which focuses on improving computational implementations and performance within a fixed problem definition, from conceptual innovation, which reframes what problems are posed, how success is measured, and why an approach is clinically relevant. We argue that prevailing incentive structures, training pathways, and publication norms disproportionately reward algorithmic novelty, particularly for early-career researchers, while at times undervaluing conceptual contributions that are essential for scientific maturation and clinical translation. Through representative examples from medical imaging AI, we show how insufficient conceptual grounding can lead to misaligned objectives, fragile generalization, and limited real-world impact. We conclude with actionable recommendations for researchers, mentors, reviewers, and journals to better recognize, support, and integrate conceptual innovation alongside algorithmic advances.
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Plasma Physics
Bivariate incomplete-Bessel kernels for the first nonlinear Vlasov-Maxwell response
Roberto Ricci
The weakly nonlinear response of a homogeneous magnetised
plasma is usually written as a double cyclotron-harmonic expansion. This representation is explicit, but the repeated use of the Jacobi-Anger expansion produces long sums of Bessel functions and nested resonance denominators. In the linear problem we recently obtained an alternative formulation by keeping the Larmor phase unexpanded and by evaluating the characteristic integral in terms of the newly introduced incomplete-Bessel function $G_\mu(z,\psi)$. In this article we apply the same idea directly to the first nonlinear Vlasov-Maxwell equation. The nonlinear source contains the linear response of an inner mode. When this linear response is written in incomplete-Bessel form, the outer characteristic integral produces a bivariate orbit-resolvent $G_{\mu,\nu}^{(r)}(z,\psi;w,\chi)$. This function emerges therefore as the natural orbit integral generated by the first nonlinear characteristic problem. We derive the nonlinear distribution function in terms of these bivariate functions, collect the identities needed for the current projection, recover an extension of the classical double-harmonic Liu-Tripathi formula by expansion, and indicate how the nonlinear susceptibility tensor is obtained from bivariate angular contractions.
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Materials Science
Spin point group symmetry and classification of non-relativistic spin splitting in non-collinear magnetic structures: Identification of high-order spin splitting types (l=5,7, and 9)
Luis Elcoro, Jesus Etxebarria, J. Manuel Perez-Mato et al. (+1 more)
A comprehensive study of the possible types of non-relativistic
spin splitting of electronic bands in coplanar and non-coplanar
magnetic structures is presented on the basis of
spin-group theory. First, we tabulate all non-equivalent
spin point groups (SpPGs) which can be expressed as a direct product of a nontrivial part and a
spin-only group limited to be the intrinsic (trivial) one, or augmented by the time-reversal (TR) operation. This tabulation, which includes the listing of
symmetry operations for 1249 nonequivalent SpPGs, is now available as an online database SPGENPOS in the Bilbao Crystallographic Server (BCS). This extends previous enumerations, in which the possible presence of TR in the
magnetic point group was not taken into account, thus overlooking the full SpPG
symmetry associated with the numerous
magnetic structures which have a
magnetic space group of type IV. For each of the listed coplanar and non-coplanar SpPGs, the
spin-splitting that is
symmetry allowed is analyzed in detail using the program STENSOR also in the BCS. Except for the SpPGs that include the operation 1', i.e., the combined operation of TR and space inversion, all other coplanar and non-coplanar SpPGs allow
spin splitting at some order in a power expansion of the electron wave vector components. We find that, depending on the SpPG,
spin-splitting terms can appear with the lowest-order monomials ranging from l=0 to 9, with the exception of l=8. This contrasts with the collinear case, where the lowest order is not higher than l=6, and where TR forbids any
spin splitting. For the newly identified
spin textures with powers l=5, 7, and 9, which are possible in some noncentrosymmetric SpPGs, the functional form of the
spin splitting in terms of the components of the
crystal momentum is given. One example of a real material, LaMnAu5, showing l=5
spin splitting is identified.
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All authors Luis Elcoro, Jesus Etxebarria, J. Manuel Perez-Mato, Emre S. Tasci
Fluid Dynamics
Multi-objective Bayesian optimization of rigid and flexible nozzles for energy-efficient pulsed jet propulsion
Paras Singh, Yukesh Karki, Victor Hernandez et al. (+3 more)
The biomechanics of pulsed-jet propulsion in aquatic animals, including squids and jellyfish, provide valuable insights into energy-efficient locomotion. In these organisms, flexible funnel deformation enables rapid acceleration and maneuverability while minimizing energy use. Drawing inspiration from these biological systems, this study investigates performance trade-offs between rigid and flexible nozzle geometries in pulsed-jet propulsion systems. A multi-objective
Bayesian optimization framework integrated with three-dimensional fluid-structure interaction (FSI) simulations identifies nozzle designs that maximize hydrodynamic impulse and minimize jet energy input. The optimization reveals fundamentally distinct performance characteristics for rigid and flexible nozzles. Rigid nozzles achieve the highest impulse amplification, up to 5 times that of a baseline cylindrical nozzle, but at substantially increased energy expenditure. In contrast, flexible nozzles yield lower peak impulse enhancement of about 2.5 times while achieving significantly greater propulsion efficiency. The maximum normalized impulse-to-energy ratio for flexible nozzles is about 1.8 times higher than that of rigid configurations, indicating more effective conversion of input energy into useful propulsive output. Analysis of the flow physics shows that optimized rigid nozzles enhance performance through geometry-induced internal entrainment, secondary
vortex formation, and contraction-driven jet acceleration. This results in stronger
vortex circulation and downstream convection. Flexible nozzles use traveling expansion-contraction deformation waves that promote additional entrainment during expansion and accelerate the internally entrained fluid during contraction to improve pressure recovery, reduce pressure-energy expenditure, and mitigate negative pressure impulse contributions.
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All authors Paras Singh, Yukesh Karki, Victor Hernandez, Daehyun Choi, Saad Bhamla, Chandan Bose
Computational Physics
Acceleration of an algebraic multigrid pressure solver using graph neural networks
Eric Chillón, Artur K. Lidtke, Nguyen Anh Khoa Doan et al. (+1 more)
Solving the pressure-Poisson equation remains the primary computational bottleneck in incompressible unstructured flow solvers primarily due to the inherent sensitivity of traditional linear solvers to mesh irregularities. This work introduces a data-driven algebraic multigrid (AMG) smoother that uses a modified graph convolutional isomorphism network (GCIN). The graph neural network predicts optimal
polynomial coefficients to construct a sparse pseudo-inverse operator across diverse grid
topologies. The coefficients are optimized to reduce the residual after each V-cycle iteration. By directly capturing the algebraic structure of the system from the sparse coefficient
matrix, the proposed method maintains the solver's linearity while adapting to local anisotropies in unstructured grids. Our framework demonstrates significant performance gains by reducing the number of V-cycles required for a given tolerance and delivering wall-clock speedups from 4% to 37% across diverse
benchmarks. Notably, the model exhibits robust generalization by maintaining efficiency on meshes up to 128 times larger than those seen in training, and by accelerating the solver's convergence on unseen industry-relevant problems such as the AirfRANS
dataset.
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All authors Eric Chillón, Artur K. Lidtke, Nguyen Anh Khoa Doan, Bernat Font
Astrophysics of Galaxies
Ages of the resolved stellar populations inside the JWST/MIRI bubbles in NGC 628
Avinash Ck, Divakara Mayya, Alessandro Bressan et al. (+3 more)
JWST images in the MIRI filters are characterized by prominent interstellar bubbles, most of which are expected to be created by mechanical energy injected into the interstellar medium by dying massive
stars. In this work, we use resolved
stellar populations (RSPs) in JWST/NIRCam images of NGC 628 from the JWST-FEAST
dataset to determine the demography of
stellar populations within these bubbles by comparing them with PARSEC+COLIBRI isochrones using a
Bayesian framework. Our analysis reveals the presence of multiple
stellar populations younger than 100 Myr within the bubbles, suggesting secondary
star formation following the first generation of
stars that formed the bubble. We find a clear preference for the most recently formed
stars to lie closer to the bubble shell. In contrast, relatively older
stars are distributed throughout the bubble interior, consistent with a scenario in which
stars formed in dense shells are left behind as the shell expands. We also examine PHANGS-HST cluster candidates within large bubbles and find no convincing progenitor clusters responsible for the initial trigger, indicating that low-mass clusters or OB associations may be sufficient to drive the initial expansion. However, the cluster may dissolve as it co-evolves with the bubble, producing the dispersed
stellar distributions observed in larger bubbles. We establish a fundamental plane relation for
stellar feedback-driven bubbles that involves the
stellar population mass, age, bubble size, gas density, and feedback efficiency, highlighting the ability of JWST/NIRCam CMDs to characterize
stellar populations driving interstellar bubble expansion in nearby
galaxies
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All authors Avinash Ck, Divakara Mayya, Alessandro Bressan, Jairo Andres Alzate Trujillo, Léo Girardi, Bolivia Cuevas-Otahola
Solar and Stellar Astrophysics
Multi-Thermal CME Detection with ALMANAC
Thomas Williams, Christopher B. Prior, David MacTaggart et al. (+1 more)
Reliable identification of low-coronal CME origins remains a key limitation in space weather
forecasting with coronagraphs not directly resolving low-coronal signatures. We present a re-engineered multi-thermal implementation of the ALMANAC
algorithm, designed to detect eruptive signatures in EUV observations. The framework extends the method to a multi-wavelength system, improving robustness against projection effects, instrumental artifacts, and wavelength-dependent ambiguities via complementary temperature responses. A spatiotemporal clustering scheme merges detections across channels, reducing event bifurcation and improving coherence while maintaining NRT performance through parallel computing. Benchmarking against 20
halo CMEs from CDAW shows improved interpretability and operational usability, with clearer separation of eruptions and more consistent onset localisation relative to coronagraph estimates. The main benefits arise from improved event discrimination, reduced fragmentation, and more interpretable source region identification. ALMANAC shows sensitivity to precursor low-coronal activity not always captured in white-light catalogues, highlighting its advantages for early warning detection. When coupled with the ARTop framework, it enables co-analysis of coronal intensity variability and photospheric
magnetic evolution. In this context, kurtosis time-series from multi-wavelength EUV data exhibit recurrent pre-eruptive spikes that frequently align with enhancements in
magnetic winding and helicity injection. Across multiple regions, these signatures often precede
solar activity, including potential discrimination of X-class
flares, while remaining suppressed during magnetically quiet intervals. Overall, integrating coronal diagnostics with photospheric
topology offers a pathway toward improved eruption
forecasting and space weather prediction.
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All authors Thomas Williams, Christopher B. Prior, David MacTaggart, Huw Morgan
Quantum Physics
Quantum-Classical Auxiliary-Field Quantum Monte Carlo at the Edge of Practicability
Francesco Nappi, Matthew Kiser and Fedor Šimkovic IV
We introduce algorithmic improvements to
quantum-classical auxiliary-field
quantum Monte Carlo (QC-AFQMC) that reduce the dominant per-step classical scaling from $\tilde{\mathcal{O}}(N^{5.5})$ to $\tilde{\mathcal{O}}(N^{4.5})$ as a function of the number of molecular
spin-orbitals $N$. Central to this improvement is the application of Aitken's block transformation to handle singular Pfaffians arising in the estimation of overlaps between a
quantum trial state and classical Slater-determinant walkers. Together with the use of algorithmic differentiation for the computation of the force bias, this yields a $248\times$ estimated runtime improvement for a system of 100 molecular orbitals. Using our workflow, we demonstrate a ground-state energy calculation for $H_8$ from
quantum data collected on IQM Emerald and post-processed with a tensor-network-based error-mitigation technique. We further validate the method's scalability through noiseless simulation of hydrogen chains up to $H_{12}$, and on the lithium-air battery related rearrangement pathway of the $Li_2O_4$ lithium superoxide dimer in a (26e, 20o) active space. We estimate both
quantum and classical runtimes for a potential fault-tolerant implementation of QC-AFQMC, showing that the method holds promise for the early fault-tolerant era. These results move QC-AFQMC a step closer to treating chemically relevant systems.
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Medical Physics
Introduction to Quantum Ophthalmology
Mukhit Kulmaganbetov, Dmitry Pushin, Taranjit Singh et al. (+6 more)
Quantum technologies are rapidly advancing across multiple research domains, with a growing impact on biomedical imaging and sensing. We examine their emerging role in ophthalmology through four complementary directions:
photon-limited retinal imaging, correlation based imaging, nanoscale optical probes, and
quantum-limited visual perception. Advances in optical coherence
tomography and single-
photon detection enable imaging under strict
photon budget constraints, reducing phototoxicity while preserving image quality. Correlation-based approaches, including ghost imaging, offer alternative strategies for image formation in low-light and scattering environments, although practical implementation remains limited by detection efficiency and acquisition time. In parallel, nanoscale optical platforms such as
quantum dots provide tunable and photostable probes for enhanced contrast and targeted delivery, with ongoing challenges related to biocompatibility and clinical translation. Finally, experiments at the single-
photon level and with structured light fields demonstrate how the visual system itself operates near physical detection limits and can be probed using controlled optical states. While many of these approaches remain at an early stage, they collectively illustrate how
quantum and
quantum-inspired methods may augment current ophthalmic imaging and diagnostic technologies while providing new tools for studying visual function under well-defined physical constraints.
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All authors Mukhit Kulmaganbetov, Dmitry Pushin, Taranjit Singh, Pinki Chahal, David Cory, Iman Salehi, Andrew Silva, Ben Thompson, Dusan Sarenac
Pattern Formation and Solitons
Supratransmission in Lattices with Purely Nonlinear Coupling
Defri Ahmad, Tae-Yeon Kim, Andreas Schiffer et al. (+2 more)
Supratransmission is examined in nonlinear
lattices with purely nonlinear coupling, extending the phenomenon to systems that lack a linear pass band. In contrast to standard
lattices with mixed linear-nonlinear interactions, the present model has no linear spectrum, so energy propagation arises entirely from nonlinear effects. Asymptotic analysis yields a discrete $p$-Schrödinger (DpS) equation that {provides an accurate description in the weak- and intermediate-coupling regimes and offers qualitative insight in the strong-coupling regime}. Perturbation provides analytical approximations for the critical driving amplitude, explicitly showing its dependence on the driving frequency, coupling strength, and the nonlinearity exponent $p$. The analysis identifies a non-trivial dependence of the critical amplitude on $p$, with distinct trends in different coupling regimes. Numerical continuation and direct simulations {validate the theory in regimes where the asymptotic reduction is applicable and show good agreement across a wide range of parameters}. The results establish supratransmission in fully nonlinear
lattices and clarify the associated energy-transport mechanisms, with relevance to mechanical
lattices, tunable metamaterials, and nonlinear optical arrays.
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All authors Defri Ahmad, Tae-Yeon Kim, Andreas Schiffer, Jinkyu Yang, Hadi Susanto
Solar and Stellar Astrophysics
Global Multi-ion Solar Wind Model. I. Ion Temperatures
Bart van der Holst, Judit Szente and Enrico Landi
Over the past several decades, observations have shown that minor ions have a higher temperature and flow faster than
protons in the
solar wind. Theories based on
turbulence have been developed that can explain many of these observed phenomena. We present our first step in developing a global multi-ion
solar wind model with
turbulence by including ion temperatures but not yet including differential streaming. The extent of this model is from the lower transition region (50,000 K temperature) to the corona and inner heliosphere. It uses low-frequency, reflection-driven incompressible
turbulence to address coronal heating and
solar wind acceleration. The energy partitioning of the
turbulence dissipation to the electrons and various ions is based on
stochastic heating and linear Landau and transit-time damping. In order to test the validity of our approach we have carried out a three-dimensional simulation of the
solar corona and the
solar wind using an idealized dipole
magnetic field configuration, calculated the Oxygen temperature across the entire domain, and compared it to measurements obtained from the UltraViolet Coronagraph Spectrometer (UVCS) on the
Solar and Heliospheric Observatory (SOHO) satellite and with the
Solar Wind Ion Composition Spectrometer (SWICS) on board Advanced Composition Explorer (ACE). The comparison shows that even with the simplified
magnetic field configuration the multi-ion model predictions reproduce the heavy-ion preferential heating phenomena in both remote-sensing and in-situ observations.
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Nuclear Theory
R. M. Francisco, D. S. Rosa, T. Frederico et al. (+1 more)
We investigate the
geometric structure of two-
neutron halo nuclei from the perspective of Efimov physics. Using the analytic three-body wave function obtained from the Faddeev equations in the
unitary limit, we explore the connection between Efimov universality and the spatial configuration of these weakly bound systems. The internal geometry is quantified through probability densities, root-mean-square interparticle distances and characteristic opening angles, evaluated for different
neutron-core mass ratios. Our results reveal a universal trend in the geometry of s-wave dominated
halo nuclei, reflecting the universal correlations characteristic of the Efimov-like regime.
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All authors R. M. Francisco, D. S. Rosa, T. Frederico, M. T. Yamashita
General Relativity and Quantum Cosmology
Distinct Near-Horizon Trend of Synchrotron Polarization in Kerr Spacetime
Yehui Hou, Jiewei Huang and Bin Chen
We show that the near-horizon expansion of the linear polarization vector for synchrotron emission in a Kerr background admits a distinct analytic form. For emission from a stationary, axisymmetric, degenerate electromagnetic field, the leading-order polarization pattern depends only on the Kerr
spin and the source polar angle, while the next-to-leading-order correction further encodes the
geometric and rotational structure of the electromagnetic field. Our result extends the equatorial analysis of [Hou et al. (2024)] and the off-equatorial leading-order result of [Chael et al. (2026)]. Near-horizon polarization thus offers a potential probe of the fundamental properties of rotating black holes and of gravito-electromagnetic interactions.
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Earth and Planetary Astrophysics
JWST-TST High Contrast: First Direct Spectroscopy of GJ 504 b reveals Clouds and Possible Metal Enrichment
Aneesh Baburaj, Jean-Baptiste Ruffio, Marshall Perrin et al. (+27 more)
Characterizing the coldest directly imaged companions through direct spectroscopy has only recently become possible with the James Webb Space
Telescope. We present moderate-resolution (R $\sim$ 2,700) spectroscopic observations of the directly imaged planetary-mass companion (PMC), GJ 504 b, using the $JWST$/NIRSpec. As the coldest imaged PMC of the pre-JWST era GJ 504 b is too faint for ground-based spectroscopy, with only photometric observations possible. Leveraging advanced post-processing techniques with a forward modeling framework, we detect the companion at high signal-to-noise (S/N$>$300). We also present the first successful PSF subtraction with angular differential imaging (ADI) in the NIRSpec point cloud, detecting GJ 504 b at S/N$>10$ and reaching contrast limits $<10^{-4}$. The extracted 2.9–5.3 $\mu m$ spectra show strong signatures of several molecular species, including H$_2$O, $^{12}$C$^{16}$O, CH$_4$, CO$_2$, NH$_3$, H$_2$S, $^{13}$C$^{16}$O, and $^{12}$C$^{18}$O. Atmospheric modeling of the spectra using petitRADTRANS, yields an effective temperature = 564$\pm$4 K, surface
gravity $\log{g}$ = 4.87$^{+0.13}_{-0.12}$,
metallicity [M/H] = 0.67$^{+0.13}_{-0.12}$, C/O ratio = 0.64$^{+0.02}_{-0.02}$, interstellar $^{12}$C/$^{13}$C and $^{16}$O/$^{18}$O isotopologue ratios, and strong evidence of disequilibrium chemistry and salt clouds. The retrieved parameters indicate a mass 25.2$^{+8.4}_{-6.0}$ $M_\mathrm{Jup}$, which is in agreement with the mass range (19–27 $M_\mathrm{Jup}$) obtained from ATMO evolutionary models, implying an age of 2.5–4.0 Gyr. Lastly, we compare the abundances of GJ 504 b to its primary, obtaining a
stellar abundance of sulfur (S), super-
stellar carbon (C), and possibly, oxygen (O). The observed metal enrichment tentatively supports
planet-like formation, but does not entirely exclude
stellar abundances for GJ 504 b.
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All authors Aneesh Baburaj, Jean-Baptiste Ruffio, Marshall Perrin, Jerry W. Xuan, William O. Balmer, Yayaati Chachan, Quinn M. Konopacky, Travis S. Barman, Mathilde Mâlin, Kielan K. W. Hoch, Emily Rickman, Kimberly Ward-Duong, Laurent Pueyo, Julien H. Girard, Isabel Rebollido, Alexis Bidot, Christine Chen, Kadin Worthen, Cicero Lu, Jens Kammerer, Roeland P. van der Marel, Nikole K. Lewis, Jeff Valenti, Sara Seager, Chris Stark, Rémi Soummer, Jay Anderson, Charles-Philippe Lajoie, Mark Clampin, C. Matt Mountain
Lattice Field Theory
The Collins-Soper kernel from a vacuum soft function
Anthony Francis, C.-J. David Lin, Wayne Morris et al. (+1 more)
The Collins-Soper kernel is calculated from a
vacuum soft function using space-like Wilson lines with complex-directional vectors on the Euclidean
lattice. Our pure gauge calculations with this method achieve high statistical precision in computing the soft function, whose rapidity dependence is well described by Collins-Soper
evolution across a wide range of rapidity differences. The extracted kernel contains errors comparable to those achieved in state-of-the-art
lattice calculations based on hadronic observables, but exhibits saturated behavior at large transverse Wilson-line separations.
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All authors Anthony Francis, C.-J. David Lin, Wayne Morris, Yong Zhao
Quantum Physics
Spontaneous parametric down-conversion pumped by spatiotemporal structured light
Lukas Montenegro and Rafael F. Barros
Here we investigate the all-optical control of spectral correlations in spontaneous parametric down-conversion. We show that when
photon pairs are projected onto high-order spatial modes, the spatial structure of the pump field defines the phase-matching function of the nonlinear interaction. Thus, by structuring the pump field in both space and spectrum, the biphoton spectral correlations are fully controlled. Considering a standard periodically-poled
crystal as the nonlinear medium, we show that the Gouy phase matching method proposed here can generate both spectrally uncorrelated and high-dimensional spectrally entangled
photon pairs, similarly to what is achieved with aperiodically-poled
crystals. Furthermore, we show that our method can generate a wider class of
quantum states if the pump field is a spatiotemporal wavepacket, that is, if its spatial and spectral structures are correlated.
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Instrumentation and Methods for Astrophysics
Thermal Characterization of a 6-Positioner, 6.2-mm-Pitch Module for Stage-5 Telescopes
Maxime Rombach, Malak Galal, Jonathan Wei et al. (+3 more)
Ensuring thermal stability of robotic fiber positioners is essential for reliable operation in the real environments of Stage-5
telescopes, where temperature variations can influence mechanical behavior and impact fiber-target accuracy. We present the results of thermal qualification tests conducted on 6.2-mm-pitch robotic positioner modules developed for high-density fiber positioning in next-generation astronomical systems. The positioners were characterized at discrete temperatures spanning negative 20 deg C to positive 30 deg C, representative of expected operational conditions. At each temperature point, key performance metrics, positioning repeatability, hard-stop repeatability, backlash, and non-linearity, were measured and compared to nominal performance. Across the full temperature range, the positioners maintained stable behavior with no measurable degradation in any metric and no evidence of mechanical or electrical damage. These results confirm that the 6.2-mm-pitch architecture provides the necessary thermal resilience for deployment in Stage-5
telescope instrumentation.
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All authors Maxime Rombach, Malak Galal, Jonathan Wei, Stefane Caseiro, Corentin Magnenat, Jean-Paul Kneib
Strongly Correlated Electrons
Mapping the non-equilibrium interacting Anderson Impurity Model to an effective Gaussian theory
Emmanuel Bogacz, Graham Kells and Andrew K. Mitchell
Quantum impurity models with strong electron correlations, such as the paradigmatic Anderson
Impurity Model (AIM), are central to our understanding of a range of physical phenomena including local moment formation, Coulomb blockade and Kondo screening. They describe
magnetic atoms and molecules on surfaces,
quantum dot
circuits, and correlated materials through dynamical mean field theory. The physics of such systems in strongly non-
equilibrium conditions is particularly complex and challenging to capture, whereas Gaussian models of free
fermions can be easily solved. Here we show that the time-evolving dynamics of the AIM after a quench can be described by a completely non-interacting version of the model, at the expense of coupling to additional static auxiliary degrees of freedom. Starting from the full solution of the quenched AIM using ED and DMRG, we study the properties of this mapping using numerical optimization, and uncover intriguing structure in the auxiliary system. The method allows us to understand interacting non-
equilibrium dynamics through the simpler lens of an effective non-interacting system of larger dimension.
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