General Relativity and Quantum Cosmology
Quantum-corrected thermodynamics of Schwarzschild AdS black holes in conformal Killing gravity
Saheb Soroushfar, Sayyed Mehrab Ramezani, Hoda Farahani et al. (+3 more)
We study Schwarzschild–AdS black holes in conformal Killing
gravity with non-perturbative
entropy corrections within the extended phase-space formalism. By deriving the
quantum-corrected heat capacity, Helmholtz free energy, internal energy, and Gibbs free energy, we show that
quantum corrections modify phase transition points and thermal stability mainly at small horizon radii, while classical behavior is recovered for large black holes. Critical behavior of van der Waals type appears exclusively for positive values of the conformal Killing parameter $a$. Applying the island prescription, we find that the
entanglement entropy of Hawking radiation saturates after the Page time at $S_{\text{sat}} = 2(\pi r_H^2 + \eta e^{-\pi r_H^2})$, thereby restoring unitarity. Stronger
quantum corrections increase the
entropy threshold and delay information recovery. Furthermore, we examine the universal thermodynamic relation in the extremal limit under a minimal perturbation of the AdS
curvature radius. We prove that the
quantum correction parameter $\eta$ cancels out completely, yielding the robust universal combination $U = -r_{\text{ext}}^3 / l^3$. This demonstrates that the universal relation remains stable against non-perturbative
quantum corrections to the
entropy.
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All authors Saheb Soroushfar, Sayyed Mehrab Ramezani, Hoda Farahani, Saeed Noori Gashti, Behnam Pourhassan, Izzet Sakalli
Biological Physics · Cross-listed from q-bio.NC
The effect of the excitatory feedback in anticipated synchronization and phase bistability regimes in neuronal populations
Julio N. Machado, Joana M. G. L. Silva, Katiele V. Brito et al. (+2 more)
Anticipated synchronization (AS), in which the receiver leads the sender and the phase lag is negative, can emerge in unidirectionally coupled dynamical systems when the receiver has faster internal dynamics than the sender. In cortical-like population models, AS and bistability between AS and delayed synchronization (DS) have been reported mainly in unidirectional motifs and have been proposed as possible explanations for phase relations observed in electrophysiological recordings. Because cortical areas are often connected bidirectionally, it is important to understand how excitatory feedback from the receiver to the sender affects the emergence and persistence of anticipatory synchronization and phase-bistable regimes. Here, we investigate the effect of the excitatory feedback on the phase relations between two cortical-like neuronal populations. We show that AS and phase bistability are not restricted to strictly unidirectional architectures, but remain robust in the presence of reciprocal coupling. In addition, we find that the transition from AS to DS can occur through different routes within the same motif, either via a bistable regime or via zero-lag synchronization, depending on the inhibitory coupling. More generally, the model exhibits a rich repertoire of phase relations, including: positive, negative, and zero-lag phase-lockings, as well as phase bistability, and phase-drift regimes. These results are consistent with the diversity of phase relations reported in electrophysiological experiments and suggest that fixed structural connectivity may support rapid reconfiguration of functional dynamics without requiring structural rewiring.
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All authors Julio N. Machado, Joana M. G. L. Silva, Katiele V. Brito, Rodrigo Pena, Fernanda Selingardi Matias
Superconductivity
Josephson network as a model for high-temperature superconductor and beyond: Macroscopic quantum coherence probed by microwave absorption
Adam Rycerz
Since the seminal experiment by Stankowski et al. [Phys. Rev. B 36, 7126 (1987)] on YBa$_2$Cu$_3$O$_{7-x}$, Magnetically-Modulated Microwave Absorption (MMMA) has become an important technique for detecting the superconducting transition in inhomogeneous ceramic compounds. The rise of microwave absorption below $T_c$ is accompanied by several low-field anomalies, usually attributed to the weak links between superconducting grains showing the Josephson effect, or to the dynamics of Abrikosov-Josephson
vortices. In this article, we briefly review selected theoretical models rationalizing MMMA spectra for high-temperature
superconductors, focusing on the $3$-dimensional array of Josephson junctions with random parameters including the resistivity, capacity and inductance of each junction, showing characteristic absorption anomalies observed in the experiment. The implications for recently studied microwave absorption in Josephson junction
qubits are also discussed.
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Instrumentation and Methods for Astrophysics
Wide field Slitless Spectroscopy with JWST's MIRI
Andreea Petric, Sarah Kendrew, David Law et al. (+12 more)
We present a snapshot of the ongoing efforts to obtain background-subtracted, wavelength-, and flux-calibrated spectra taken with the new Wide-Field Slitless Spectroscopy (WFSS) mode for the MIRI instrument on the James Webb Space
Telescope (JWST), offered for the first time in JWST Cycle 5 (starting July 2026). We describe here the capabilities of the new mode, the operational concept, and an overview of the calibration and pipeline development activities that are currently ongoing.
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All authors Andreea Petric, Sarah Kendrew, David Law, Alberto Noriega Crespo, Bryan Holler, Jane Morrison, Jonathan Aguilar, Misty Cracraft, Ian Wong, Stacey Alberts, Dean Hines, Kate Rowlands, Ned Molter, G. C. Sloan, Mike Engesser
Computational Physics
Scalable dynamical inference of phase-field fracture from sparse and partial measurements
Hanfeng Zhai and Zisheng Zhang
Evolving crack fields in structural health monitoring and fracture assessment must often be inferred from sparse mechanical measurements rather than dense full-field observations. We develop CNN2D–ConvGRU, a convolutional-recurrent framework for measurement-conditioned reconstruction of time-dependent phase-field brittle fracture. At each load step, the model maps a fixed-length history of phase and displacement fields and sparse current-step displacement measurements to the current full-field state. New measurements are assimilated during sequential deployment, making the framework a state-inference surrogate rather than an autonomous time integrator. It reproduces crack paths, damage
evolution, and bulk displacement response, with the largest errors near propagating crack tips and steep displacement gradients and some drift at late stages. Without retraining, weights learned on a $256 \times 256$ raster are evaluated on a $512 \times 512$ raster of the same physical domain and finite-element discretization using a proportionally refined measurement grid. This empirical raster-and-sensing transfer preserves the principal damage
topology and global damage
evolution, although fine-scale displacement errors increase near crack tips. Comparisons with alternative spatial and temporal architectures show that CNN2D–ConvGRU offers a favorable balance between reconstruction accuracy and computational cost. Relative to repeated finite-element solutions, sequential reconstruction achieves mean speedups of $175\times$ on CPU and $253\times$ on GPU. These results demonstrate efficient full-field fracture-state reconstruction from sparse observations while retaining the spatial structure and history dependence of phase-field fracture.
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Adaptation and Self-Organizing Systems
Interaction order controls stochastic-resonance enhancement and redistribution in delayed multiplex neural networks
Alina Schlabritz and Marius E. Yamakou
We investigate
stochastic resonance in a hierarchy of delayed excitable systems, from a single FitzHugh–Nagumo
neuron to single-layer and duplex networks with autaptic, pairwise, triadic higher-order, and interlayer interactions. We show that the order and organization of interactions generate distinct resonance regimes. Among the autapse-free single-layer architectures, pairwise and triadic coupling attain comparable maximal responses, but over different ranges of nominal coupling strength: the pairwise enhancement persists across the investigated coupling range, whereas the triadic enhancement is confined to weak coupling. Under the matched participation degrees used here, this difference is largely attributable to the doubled effective coupling generated by the hyperedge construction. Delayed autaptic feedback primarily shifts the optimal noise level and, within the configurations investigated, yields a genuine enhancement only when pairwise and triadic interactions coexist, revealing a non-additive coupling effect. In duplex networks, interlayer coupling acts predominantly as a response-equalization mechanism: it enhances the weaker layer, generally at the expense of the stronger one, with the redistribution controlled mainly by the uncoupled resonance-capacity gap. Across the sampled duplex configurations, increasing the interlayer delay largely suppresses the response within the investigated delay range. These results identify interaction order, resonance mismatch, and delay as key control parameters for noise-assisted signal processing in multilayer excitable systems.
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Quantum Physics
Quantum Information Analysis in a q-Deformed Deng-Fan Model
P. O. Amadi, Collins O. Edet, A. R. P. Moreirae et al. (+4 more)
We introduce a $q$-deformed Deng-Fan potential ($q$DFP) model that enables controlled modulation of short-range repulsion and long-range attraction while preserving the
equilibrium configuration. The model is solved exactly within the framework of the time-independent Schrödinger equation, yielding closed-form expressions for the energy
eigenvalues and wave functions in terms of hypergeometric functions. We show that the deformation parameter $q$ induces non-uniform spectral shifts and a redistribution of bound states. In particular, for $q<1$, the system exhibits spectral compression and enhanced spatial localization. In addition, we investigate the system from an information-theoretic perspective using Shannon
entropy, Fisher information, and Fisher–Shannon complexity measures in both position and momentum spaces. The results reveal that the deformation parameter governs the redistribution of
quantum information, establishing a direct connection between spatial confinement and momentum delocalization in accordance with the Białynicki-Birula and Mycielski entropic uncertainty principle. Stronger deformation pushes the
quantum state further from the minimum-uncertainty configuration, increasing the entropic excess above the BBM bound and reducing the information content about complementary observables, even as position-space localization sharpens. The analysis of entropic and Fisher information densities further shows how the deformation reshapes both the local information content and the structural complexity of the
quantum states. We show that in the limit $q\to 1$, the $q$DFP model is reduced to the standard Deng-Fan potential.
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All authors P. O. Amadi, Collins O. Edet, A. R. P. Moreirae, P. Kalasuwana, N.Ali, R. Endut, S. A. Aljunid
High Energy Physics (Theory)
Higher-order analogues of colour-kinematics duality in first-order Yang-Mills Feynman diagrams
Leron Borsten, Dimitri Kanakaris and Hyungrok Kim
Colour-kinematics duality is, even at tree level, not manifest from the standard Lagrangian of Yang-Mills theory in that the usual Feynman-diagram expansion does not follow the kinematic Jacobi identities. For a Lagrangian manifesting colour-kinematics duality, the kinematic Jacobi identities of the Feynman-diagram expansion follow from the existence of a second-order differential operator $\mathsf{b}$ acting on the
algebra of colour-stripped fields that forms part of the data of a BV$^\square$-
algebra. We argue that the existence of differential operators of order greater than two implies weaker but nontrivial fragments of kinematic Jacobi identities. We further show that a superspace formulation of the first-order Yang-Mills action in the Batalin-Vilkovisky formalism admits a differential operator of order six in every spacetime dimension. Therefore, the Feynman-diagram expansion of tree and loop scattering amplitudes of the first-order formulation of Yang-Mills theory automatically enjoy a weak form of colour-kinematics duality.
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Materials Science
Intrinsic Defects in Amorphous Optical Coatings of TiO$_2$-doped GeO$_2$ for Gravitational-wave Detectors
K. Prasai, K. Lee, R. Bassiri et al. (+6 more)
The increased
laser power of future gravitational-wave detectors will require mirror coatings with optical absorption below 0.1 ppm per mirror. TiO$_2$-doped GeO$_2$, currently the best high-index material for reducing room-temperature coating thermal noise, still exhibits ppm-level absorption even after extrinsic contamination is minimized. Using ab-initio simulations and absorption measurements, we identify oxygen-deficient Ti-rich environments as the origin of this residual absorption. We find that ordinary structural disorder in the amorphous network can localize electronic states but does not produce defects capable of absorbing 1064-nm light. In contrast, oxygen vacancies in compact Ti-rich environments create localized Ti$^{3+}$–Ti$^{3+}$-like polaron-pair or mixed Ti-polaron states states with transitions near 1064 nm. Photothermal measurements show increased absorption after dry/inert annealing, supporting the formation of these reduction-sensitive defects. These results show that the residual absorption is not an intrinsic limitation of TiO$_2$-doped GeO$_2$, but a process-dependent defect that may be mitigated through control of oxygen stoichiometry during deposition and annealing.
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All authors K. Prasai, K. Lee, R. Bassiri, A. Davenport, D. A. Drabold, M. M. Fejer, A. Markosyan, C.S. Menoni, S. Tait
Soft Condensed Matter
Motile Bacteria Modify Salt Precipitation Patterns in Dried Sessile Droplet
Yumeng Zhao, Boyoung Jeong, Markus C. Noll et al. (+1 more)
Motile Escherichia coli bacteria can alter salt crystallization patterns during the evaporation of sessile droplets. In dilute bacterial suspensions in deionized water, dried bacteria
cells predominantly accumulate at the droplet periphery, consistent with the classic "coffee-ring" effect. At higher
cell densities, however, the bacterial distribution becomes more uniform. In the absence of bacteria, pure Phosphate Buffered Saline also forms salt
crystals in a coffee-ring pattern. When bacteria are present alongside the salt solute, additional isolated
crystals appear near the droplet center, with their abundance increasing with bacterial concentration, while
crystals at the periphery adopt dendritic morphologies that extend radially. To investigate these phenomena, we used a Stokes-based analytical model to estimate the
evolution of internal flow fields and compare them with bacterial motility. Then a finite volume model is implemented for bacteria and salt transport and adsorption, and a
stochastic model for salt nucleation was developed, which successfully explains the crystallization pattern seen in the experiments. Our results show that bacterial motility can overcome evaporation induced flow during early stage, enabling bacteria
cells to serve as nucleation sites and thereby altering the final crystalline morphology. This work highlights the potential of motile microorganisms to actively control evaporative crystallization, with implications for porous media flow and microfluidic deposition processes.
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All authors Yumeng Zhao, Boyoung Jeong, Markus C. Noll, Sheng C. Dai
Lattice Field Theory
Exotic $B_s$ mesons in the continuum from a nonperturbatively-tuned heavy quark action
R. J. Hudspith, Daniel Mohler and M. Stolz
In this work we predict the masses and binding energies of two $B_s$ exotic-
meson candidates using
Lattice QCD, namely the $B_{s0}^*$ and $B_{s1}$. We use a relativistic heavy-
quark action for the valence b-
quark in our simulations, tuned fully non-perturbatively by a neural network. This allows us to take the continuum limit and eliminates the largest systematic we attributed to our previous determination of these states using
Lattice-NRQCD. This is the first
Lattice QCD study to show that these states remain deeply bound in the continuum limit. We thoroughly
benchmark our heavy-
quark approach by reproducing the experimental values of the 1S hyperfine splittings of $B$ and $B_s$
mesons, as well as the mass splitting between the $B$ and $B_s$
mesons. Our final results yield binding energies with respect to the $BK$ and $B^*K$ thresholds of $-65.9(6.0)(3.0)_\text{Iso}$ MeV and $-60.6(6.6)(3.0)_\text{Iso}(1.0)_\text{GEVP}$ MeV for the $B_{s0}^*$ and $B_{s1}$ respectively.
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Statistical Mechanics
Nonequilibrium Maxwell-Demon NEMD formalism for transport: I. Extrapolating shear viscosity to the hydrodynamic limit
Hesam Arabzadeh and Brad Lee Holian
The Maxwell-Demon nonequilibrium molecular dynamics method for measuring the shear viscosity divides the fluid simulation
cell into two regions of width w in the $x$-direction, with the particles allowed to move freely between the two sides. The Demon maintains equal and opposite regional average particle velocities in the $y$-direction by applying an acceleration needed to sustain the nonequilibrium steady state (NESS), which includes both total force balance and an instantaneous correction for
diffusion of particles across boundaries. We show that the driven velocity profile in x is a natural hydrodynamic response and not imposed by the constraint. For the present shear geometry, the measured NESS profile in Eulerian slabs is represented accurately by a piecewise
parabolic form, reminiscent of planar Poiseuille flow. The
parabolic profile gives an estimate of the kinematic viscosity from work done on the shearing fluid, as well as an
entropy production estimate, derived from heat removal by the Nosé-Hoover thermostat that keeps each regional average temperature constant. We show that the mechanical work supplied by the Demon equals the heat removed by the thermostat. Once NESS driving is removed, the
parabolic velocity profile relaxes exponentially in short order to sinusoidal, the natural transverse momentum-
diffusion eigenmode. Our Maxwell-Demon shear method provides a direct NEMD formalism for obtaining shear viscosity from momentum
diffusion, work, and
entropy balances. Our results in three dimensions for increasing system size $N$ (the number of particles) demonstrate that shear viscosity approaches an asymptote (the so-called hydrodynamic limit) as $N^{-1/3}$.
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Medical Physics
Proposal of a consistent value for the mean excitation energy of liquid water using advanced modeling, detailed simulations and precission proton Bragg curves
Pablo de Vera, Isabel Abril, Flávio Matias et al. (+3 more)
Protontherapy precision depends on accurately knowing the stopping power of
liquid water, as it is the most abundant component of soft body tissues. Difficulties when working with volatile
liquids have led to a long-standing debate regarding the values of the stopping power and the mean excitation energy $I$ of
liquid water. The equivalence between the stopping power of
liquid water and amorphous ice per unit mass density across all clinically relevant
proton energies opens the possibility to obtain a reliable estimation of the $I$-value of
liquid water. In this work, we employ two complementary theoretical methodologies to assess the
proton stopping power of water. The MELF-GOS (Mermin Energy Loss Function - Generalized Oscillator Strengths) approach, based on the perturbative dielectric formalism, serves as an accurate reference for sufficiently high energies, while the novel non-perturbative TDDFT-Penn (time-dependent density functional theory - Penn) method ensures accuracy for energies even below the stopping maximum. These stopping-power values were incorporated into the simulation code SEICS (Simulation of Energetic Ions and Clusters through Solids) to evaluate
proton Bragg curves from $1$ to $230$ MeV. Comparisons with available precise depth-dose measurements provide critical insights that help establish the consistent value $I = 79.4$ eV for
liquid water, providing robust physical grounds for improving range prediction for treatment planning.
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All authors Pablo de Vera, Isabel Abril, Flávio Matias, Julian M. B. Shorto, Hélio Yoriyaz, Rafael Garcia-Molina
High Energy Physics (Experiment)
Analysis note: one-point charge correlator with DELPHI Open Data
Jingyu Zhang, Yi Chen, Kyle Lee et al. (+4 more)
We present the first measurement of the one-point charge correlator, the angular flux of electric charge in hadronic final states, using DELPHI Open Data collected at LEP-1 at $\sqrt{s} = 91.2$~GeV during 1994 and 1995. The data, corrected for detector effects, exhibit a clear $\sin(2\theta)$ modulation, consistent with the parity-violating hadronic charge flow that the
chiral structure of the $Z$ couplings imprints on the final state. The measurement demonstrates the experimental feasibility of the observable and establishes strategies for controlling associated detector effects, thereby motivating a new program to measure charge-flux observables. This note documents the experimental details supporting the companion experimental paper and the joint theory–experiment Letter.
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All authors Jingyu Zhang, Yi Chen, Kyle Lee, Ian Moult, Cristian Baldenegro, Hannah Bossi, Yen-Jie Lee
Solar and Stellar Astrophysics
Determining low-$\ell$ p-mode frequency shifts in Sun-like stars: Enhancing the cross-correlation technique with filters
Samarth G. Kashyap, Laurent Gizon, Jesper Schou et al. (+1 more)
Acoustic mode frequencies in the Sun and Sun-like
stars change due to
magnetic activity, on time-scales much larger than the
star's rotation and much smaller than its
evolution. Given the poor S/N of the observed
stellar p-modes, it is challenging to measure the changes of individual mode frequencies. Typically, power spectra of different time series segments are cross-correlated to estimate a mean p-mode frequency change, which ends up averaging over the individual mode contributions. We seek to enhance the cross-correlation method, by introducing a novel and computationally cheap method, thus enabling us to disentangle p-mode frequency changes for different spherical harmonic degree $\ell$. Assuming that the inclination angle and rotation rate are already measured, filters are designed, which enable the isolation of $\delta\omega_\ell$, frequency changes of modes with a given $\ell$, while preventing bias creeping in from neighbouring modes. Monte-Carlo simulations are performed to quantify uncertainty in the estimation of $\delta\omega_\ell$. We validate our method against well-studied
solar data (SOHO/VIRGO and BiSON) and demonstrate its applicability to the
solar-like Kepler
star KIC 8006161.
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All authors Samarth G. Kashyap, Laurent Gizon, Jesper Schou, Rachel Howe
High Energy Physics (Experiment)
First measurement of the one-point charge correlator in $e^+e^-$ collisions at $\sqrt{s} = 91.2$ GeV with DELPHI Open Data
Jingyu Zhang, Yi Chen, Kyle Lee et al. (+4 more)
The
chiral structure of the $Z$ couplings imprints a parity-odd flow of electric charge on hadronic $Z$ decays. The related forward-backward asymmetries, a key set of observables in the electroweak precision program, were measured at LEP and SLC using the jet charge. The one-point charge correlator offers a complementary route, measuring the hadronic charge flow directly as a function of polar angle relative to the incoming electron-beam axis, without reference to jets or a reconstructed
quark direction, following the formalism developed in a companion paper. We report its first measurement, using $61~\mathrm{pb}^{-1}$ of archival DELPHI Open Data recorded at $\sqrt{s} = 91.2$~GeV in 1994 and 1995. Detector effects are corrected in two stages. The first is derived from fully simulated samples, and the second bounds the residual charge-misreconstruction difference between data and simulation using a measurement in $e^+e^-\to\tau^+\tau^-$ events. The measured charge correlator exhibits the characteristic parity-odd $\sin(2\theta)$ modulation and agrees with the PYTHIA~8.3 prediction. The measurement demonstrates that the parity-odd charge flow of hadronic $Z$ decays is directly accessible in data, differentially in polar angle, and the paper discusses strategies for controlling the associated detector effects, paving the way for a new program of charge-flux measurements, both in archival $e^+e^-$ data and at future
colliders.
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All authors Jingyu Zhang, Yi Chen, Kyle Lee, Ian Moult, Cristian Baldenegro, Hannah Bossi, Yen-Jie Lee
High Energy Physics (Phenomenology)
Revisiting In-Medium QCD Effects on Spin-Polarized Strange Quark Stars
Manas Lohani, Yogesh Kumar, Poonam Jain et al. (+4 more)
We investigate the properties of exotic Strange
Quark Matter with
spin polarization and the complex configuration of Strange
Quark Stars using a phenomenological MIT Bag Model, enhanced by incorporating a QCD informed running strange
quark mass dependent on the chemical potential. The effective mass using quasiparticle approach is utilized to understand the framework of SQM. The resulting Equation of State is constructed for two distinct parameter sets, yielding an energy per
baryon below the iron limit for stable configurations and thus supporting the Bodmer Witten Terazawa hypothesis that SQM could be the actual ground state of exotic matter. This framework is then used to address the Tolman Oppenheimer Volkoff equations to study the effect of
spin polarization on
stellar properties. The model predicts that the maximum
stellar mass increases with the degree of
spin polarization, a result that diverges from previous constant mass models. Furthermore, the model predictions for mass, radius, and surface
redshift are in excellent agreement with observational constraints for the compact object Vela X one. This agreement validates our theoretical approach and strengthens the candidacy of Vela X one as a Strange
Quark Star. Overall, the model results highlight the importance of in medium QCD effects in describing dense matter.
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All authors Manas Lohani, Yogesh Kumar, Poonam Jain, Om Prakash, Sanjay Tyagi, Vinod Kumar, T. A. Nahool
Computational Physics
Conforming and nonconforming Trefftz approximations for two-dimensional scalar electromagnetic problems
Igor Tsukerman
Trefftz functions satisfy the differential equation locally and exactly; quasi-Trefftz functions do so approximately to prescribed high order. This paper considers (quasi-)Trefftz approximations for two-dimensional scalar electromagnetic problems. Established discretizations include the Flexible Local Approximation MEthod (FLAME), Trefftz elements ($T$-elements), and Trefftz discontinuous Galerkin (Trefftz-DG) methods. New developments are gradient-enriched FLAME (GEFLAME), conforming Trefftz–FLAME finite elements (TFF), and a full-field Bloch-wavevector-vs-frequency solution with Schur–DtN reduction. Applications cover electrostatics, scattering, singular fields, and Bloch waves in periodic structures. These methods make different compromises between conformity and flexibility. FLAME and GEFLAME incorporate Trefftz functions directly into local difference schemes; TFF uses elementwise FLAME schemes to lift
polynomial traces into element interiors; $T$-elements match elementwise Trefftz spaces weakly to such traces; and Trefftz-DG couples broken Trefftz spaces through fluxes and penalties. In the reported wave-scattering examples, GEFLAME gives field and gradient errors several orders of magnitude below those of the quadratic finite-element discretization at comparable algebraic cost. Localized singular-function enrichment removes the dominant reentrant-corner error. Conforming TFF and quasi-conforming $T$-elements admit standard finite-element assembly but expose
polynomial edge traces as an accuracy bottleneck. For periodic media, the bilinear Trefftz-DG formulation gives an analytic
polynomial wavenumber-vs-frequency eigenproblem without restricting the Bloch multiplier to the unit circle. Schur–DtN reduction yields compact boundary-response problems.
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Medical Physics
Whole Blood-Based Point-of-Care Assay for Single-Tier Lyme Disease Testing
Mihye Lee, Rajesh Ghosh, Artem Goncharov et al. (+10 more)
Rapid point-of-care diagnostics that operate directly on whole blood can accelerate clinical decision-making by bypassing complex sample preprocessing and centralized laboratory infrastructure. However, most serologic assays still require serum or
plasma, limiting near-patient deployment. This challenge is particularly evident for Lyme disease, whose diagnosis relies on centralized two-tier serology. Here, we present a whole-blood multiplexed vertical flow assay (WB-xVFA) that performs single-tier Lyme serology directly from 50 microliter of whole blood. The assay combines multilayer blood filtration with a peptide-patterned nitrocellulose membrane to separate cellular components and detect Lyme-associated IgM/IgG responses on a cartridge. Coupled with smartphone-based imaging and machine-learning analysis, the WB-xVFA provides results in 20 min. The assay remained robust across hematocrits up to 60% and sample volumes ranging from 25 to 100 microliter. In blinded testing of 62 whole-blood measurements, it achieved ~97% sensitivity and specificity, demonstrating the feasibility of rapid, near-patient whole-blood Lyme serology.
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All authors Mihye Lee, Rajesh Ghosh, Artem Goncharov, Rui-Chian Tang, Barath Palanisamy, Gyeo-Re Han, Adrian Anaya, Elizabeth J. Horn, Paul M. Arnaboldi, Raymond J. Dattwyler, Omai B. Garner, Aydogan Ozcan, Dino Di Carlo
Materials Science
What makes a useful molecular model of biochar? A community roadmap
Valentina Sierra-Jimenez, Jonathan P. Mathews, Luca Bellucci et al. (+22 more)
Biochars are disordered carbonaceous materials produced by biomass pyrolysis, with applications spanning soil amendment, water remediation, carbon storage, and functional materials. Although they share structural features with other disordered carbons such as coal, kerogen, and activated carbons, the questions posed to biochar models are distinct, and no single model can answer all of them equally well. Model usefulness must be defined relative to a specific question and validated against independent experimental observables. This community roadmap, arising from a CECAM workshop, critically maps current molecular approaches: experimentally guided top-down reconstruction, mimetic bottom-up simulation, and hybrid methods. We argue that first-generation models have been more successful than is often acknowledged, provided they are built at sufficient length scale and with explicit control over microporosity and bulk chemistry. Structural and
equilibrium interfacial properties are increasingly tractable with classical force fields, whereas dynamic and reactive behaviours require selective use of reactive methods within multiscale workflows. A parallel, largely unaddressed gap concerns the mineral and ash components of biochar, and the changes the material undergoes during ageing in soil. We identify seven open questions current models cannot yet answer reliably, and five community priorities: force field benchmarking, open model and data repositories, shared classification and metadata standards, ensemble validation, and training in reproducible practice. Across these, sustained interaction with experimentalists is essential to ground models in real observables and document where they fail. Progress will be accelerated by adapting transferable methods from coal, kerogen, and clay-organic matter frameworks rather than repeating trial-and-error development.
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All authors Valentina Sierra-Jimenez, Jonathan P. Mathews, Luca Bellucci, Edo Boek, Carla de Tomas, Manuel Garcia-Perez, Stef Ghysels, Paola Giudicianni, Corinna Maria Grottola, Kelly Anne Hawboldt, Robert L. Johnson, Fenna B.E. Kolff, Jean-Marc Leyssale, Diego Liberati, Francisco J. Martin-Martinez, Jacob W. Martin, Ondřej Mašek, Mohammad Mezbah Ul Hoque, Audrey Ngambia, Amaël Obliger, Frederik Ossler, Muhammad Riaz, John M. Tobin, Xiaolei Zhang, Valentina Erastova
Nuclear Theory
Aoumeur Daddi Hammou, Jean-Paul Blaizot, Pol Bernard Gossiaux et al. (+1 more)
Accurate modelling and understanding of quarkonium production in ultrarelativistic heavy ion collisions requires a formalism that preserves the
quantum properties of microscopic $\bar{Q}Q$ systems while treating the interaction of such pairs with the
quark-
gluon plasma (QGP). The open
quantum system approach has recently emerged as one of the most fruitful schemes to meet such requirements. However, the
quantum master equations obtained so far in this context are derived assuming a strict ordering between the QGP temperature $T$ and the $\bar{Q}Q$ energy gaps ($\Delta E$) of the quarkonia bound states. This limits their predictive power since, as the QGP expands and cools down, the system traverse all regimes between the
quantum Brownian motion (QBM) regime for $T\gtrsim \Delta E$ to the
quantum optical (QO) regime for $\Delta E\gtrsim T$. In this paper, we derive and present a more general non-abelian
quantum master equation of the Lindblad type, which does not suffer from these limitations and thus allows to faithfully describe the
quantum evolution of the $Q\bar{Q}$ pairs during the whole QGP-
evolution. We also provide some illustration of the key quantities governing this equation.
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All authors Aoumeur Daddi Hammou, Jean-Paul Blaizot, Pol Bernard Gossiaux, Thierry Gousset
Mathematical Physics · Cross-listed from math.AP
Resonant Geometry and Well-Posedness for the 2D Boussinesq Wave Kinetic Equation
Haoling Xiang
We study the wave kinetic equation (WKE) derived by Shavit–Bühler–Shatah from the two-dimensional Boussinesq system of internal waves. The equation is anisotropic and vector-valued, with a two-branch sign-changing dispersion relation, coupled propagation branches, and a sign-indefinite pseudo-momentum invariant. The resonant
manifold has angular degeneracies that obstruct the standard analytic treatment of the collision operator. We introduce a natural angular cut-off adapted to these degeneracies, prove boundedness of the cut-off collision operator, and establish local well-posedness in weighted $L^\infty$ spaces. We also show that, even with the zero-frequency cut-off retained, removing the cut-off near $|\cos\theta|=\tfrac12$ makes the collision operator unbounded on these weighted spaces. This provides, to our knowledge, the first rigorous analytic framework for an anisotropic vector-valued WKE arising from Boussinesq dynamics.
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Astrophysics of Galaxies
Improved constraints on the Milky Way potential using the M68 stream and DESI spectroscopic data
Carles G. Palau, Wenting Wang, Jiaxin Han et al. (+41 more)
We present a selection of
stars belonging to the
stellar stream of the M68 (NGC 4590) globular cluster, also known as Fjörm. This
star selection is an improvement on previous ones that used only
Gaia data, as it incorporates spectroscopic measurements from the DESI survey and photometric data from the DESI Legacy Surveys. The selection contains 96
stars, each with five phase-space parameters from
Gaia-DR3 and radial velocity from DESI, covering the entire observed section of the stream. This constitutes the largest selection of M68 stream
stars with measured radial velocities to date. The observed stream is wider than expected from N-body simulations, and the
stars farthest from the centre of the stream appear to be correlated in radial velocity space. This suggests that these
stars cannot have been stripped from the cluster in a static axisymmetric potential. By modelling a mock sample of stream
stars created using an N-body simulation, we found that we could reliably constrain the disc mass $M_{\rm d}$ and the dark matter
halo axis ratio $q_{\rm h}$ of the Milky Way. This is because the stream flows close to and almost parallel to the disc. Using the 44
stars that are consistent with having been stripped from the cluster, combined with measurements of the Milky Way's rotation curve, we constrain the
Galactic potential, obtaining $M_{\rm d} = 5.34 \pm 0.57 \times 10^{10}$ M$_{\rm sun}$ and an oblate
halo of $q_{\rm h} = 0.83^{+0.06}_{-0.05}$. Additionally, by fitting the stream track, we estimate the Heliocentric distance of M68 to be $r=10.55\pm0.09$ kpc.
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All authors Carles G. Palau, Wenting Wang, Jiaxin Han, J. Aguilar, S. Ahlen, F. Beutler, D. Bianchi, D. Brooks, A. Carnero Rosell, F. J. Castander, T. Claybaugh, A. Cuceu, A. de la Macorra, J. E. Forero-Romero, E. Gaztañaga, Satya Gontcho A Gontcho, G. Gutierrez, J. Guy, D. Kirkby, A. Kremin, M. Landriau, L. Le Guillou, A. Leauthaud, G. E. Medina, A. Meisner, R. Miquel, S. Nadathur, H. E. Noriega, E. Paillas, N. Palanque-Delabrouille, W. J. Percival, F. Prada, I. Pérez-Ràfols, C. Ravoux, G. Rossi, R. Ruggeri, E. Sanchez, C. Saulder, D. Schlegel, M. Schubnell, M. Siudek, G. Tarlé, B. A. Weaver, H. Zou
Materials Science
Barium Hexaferrite Thin Films as a Scalable Magnetic-Insulator Platform for Proximity-Engineered Spintronics
Shyam Sundar Poriah, Sanjana D. S., Agrim Sharma et al. (+8 more)
Rare-earth iron garnets, such as yttrium iron garnet (YIG) and thulium iron garnet (TmIG), are the
benchmark magnetic insulators for spintronic and magnonic devices, but achieving usable perpendicular
magnetic anisotropy (PMA) in these materials typically relies on substrate strain- engineering, requiring careful
lattice-matching and specific growth conditions that constrain ma- terial accessibility. Here we establish sputter grown barium hexaferrite (BaFe12O19, BaM) as a
magnetic-
insulator alternative with strong intrinsic perpendicular anisotropy, requiring no strain engineering. X-ray diffraction, transmission electron microscopy and Raman spectroscopy confirm stoichiometric films with atomically smooth surfaces, while first-principles calculations corroborate a robust ferrimagnetic ground state. The films exhibit square out-of-plane hysteresis with a coercive field of nearly 0.1 T. Unlike rare-earth garnets, the perpendicular anisotropy in BaM is intrinsic to its magnetoplumbite
crystal structure, arising independent of highly ordered strain. Interfaced with Pt and with exfoliated BiSbTeSe2 (BSTS), BaM induces proximity induced anomalous
Hall trans- port, confirming efficient interfacial exchange coupling, while the BSTS/BaM
heterostructure shows an additional
Hall contribution suggestive of non-collinear interfacial
spin textures. These results position BaM thin films as a scalable
magnetic-
insulator platform for spintronic and topological
heterostructure devices beyond the constraints of garnet chemistry.
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All authors Shyam Sundar Poriah, Sanjana D. S., Agrim Sharma, Sreelakshmi M. Nair, Pankaj Bhardwaj, Laxmipriya Nanda, Aryaman Das, Jagadish Rajendran, R. S. Patel, Manish Jain, Dhavala Suri
Other Condensed Matter
Tracking Chirality during Molecular Motor Photoisomerization via Simulated Time-Resolved Circular Dichroism
Leonardo Biancorosso, Ali Hassanali, Mauro Stener et al. (+3 more)
Ultrafast spectroscopic techniques are widely used to investigate photoinduced processes, yet they remain largely blind to molecular chirality. Here we introduce a framework for simulating time-resolved electronic circular dichroism (TRCD) along an ensemble of nonadiabatic molecular dynamics, and apply it to the photoisomerization of a second-generation molecular motor[1]. While transient absorption captures the overall excited-state dynamics, it cannot distinguish the two photoproduct pathways. The TRCD response, by contrast, resolves the stereochemical branching: trajectories returning to the stable P isomer (right-handed helix) retain a distinct chiroptical band in the visible region, whereas those forming the M isomer (leftl-handed helix) become chiroptically dark as they twist through the conical intersection. This asymmetry constitutes a directly measurable signature of the stereochemical branching, offering a real-time probe of the formation of molecular chirality and concrete predictions for future TRCD experiments.
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All authors Leonardo Biancorosso, Ali Hassanali, Mauro Stener, Emanuele Coccia, Marta Monti, Gonzalo Díaz Mirón
Quantum Physics
Transitions to super-radiance in ensembles of incoherently pumped emitters
Laszlo Rassaert and Tommaso Roscilde
Super-radiance is a striking phenomenon resulting from the collective interaction of emitters with light, and it is fundamentally related to the appearance of long-range correlations between the dipole moments of the emitters. As such, it represents a distinct phase of dissipative many-body systems compared to the case of independent emitters, similarly to how ferromagnetism stands out in
magnetic materials in contrast to paramagnetism. In this work we address the conditions under which the transition to super-radiance can occur in ensembles of emitters subject to dephasing and individual decay – a situation which is particularly relevant to the case of emitters in the solid state. The simplifying assumption of an ensemble of permutationally invariant emitters allows for the efficient solution of both the dissipative dynamics after a pulsed excitation, as well as of the steady state under incoherent pumping. This exact solution allows us to
benchmark a truncated cumulant expansion approach, which can give predictions for arbitrarily big system sizes. We show that super-radiance is fundamentally robust to sizable dephasing and non-radiative decay rates, both under a pulsed excitation, as well as under continuous pumping. This robustness is the result of the collective acceleration effect of super-radiant emission with respect to the individual coupling to a local environment. We establish the universal critical scaling laws at the transition between normal radiance and super-radiance; and we show that, in the super-radiant phase, significant finite-size crossovers can be observed before reaching the asymptotic scaling regime. Our results pave the way for future experiments to provide a quantitative characterization of the scaling properties of super-radiance, seen as a distinct non-
equilibrium many-body phase in ensembles of incoherently pumped emitters.
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Quantum Gases
Three-body contact for fermions. II. Non-degenerate limit
Xavier Leyronas and Félix Werner
A fundamental quantity characterizing
Fermi gases with zero-range interactions is the three-body contact $C_3$, which determines several observables including the number of nearby triplets of
fermions and the three-body loss rate in cold atom experiments, as shown in a companion article. Here, we compute $C_3$ to leading order in the non-degenerate limit for the homogeneous gas with negative or infinite scattering length $a$. At $a=\infty$, using a wavefunction approach, we obtain the analytical expression of $C_3$, which has a remarkably slow $1/T^{0.22728}$ dependence on the temperature $T$. In the Feynman diagram technique, which we use for $a<0$, the correct three-body short-distance correlations emerge only after a non-trivial cancellation between leading order two-body and three-body correlations, and the resulting power-law scaling comes from the large-wavevector tail of the 3-body T-
matrix, which we derive inspired by the analytical solution of the three-body problem at the
unitary limit.
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Fluid Dynamics
The Geometry of Stochastic Fluid Dynamics
Darryl D. Holm
Stochastic geometric mechanics (SGM) is known for its potential utility in quantifying uncertainty in global
climate modelling of the Earth's ocean and atmosphere while also preserving the fundamental advective transport properties of ideal fluid flow. This paper is a pedagogical review of the recent developments of the mathematical framework of
stochastic geometric mechanics obtained from Lie group-invariant
stochastic variational principles in the context of model building for upper ocean dynamics, The paper is divided into the following five parts. Part I discusses the origins of
geometric mechanics applications in deterministic fluid dynamics. Part II focuses on the example of the deterministic 3D Euler Boussinesq (EB) equations. Part III adds
stochastic transport to the 3D Euler Boussinesq (EB) and derives its SALT equations. (SALT is the abbreviation of
Stochastic Advection by Lie Transport.) Part IV focuses on Lagrangian Averaged
Stochastic Lie Transport, abbreviated as LA-SALT. LA-SALT treats atmospheric `
climate' as the ensemble expectation, while the atmospheric `weather' is treated as a field of pathwise fluctuations, as discussed in Ed Lorenz's famous 1995 lecture. Part V applies SALT and LA-SALT to create
stochastic Ocean–Atmosphere Models, abbreviated as SOAM.. The SOAM approach brings us back to Hasselmann's 1976 paradigm, which decomposes a general
climate model into its deterministic and
stochastic parts.
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Soft Condensed Matter
Growth-Induced Transitions in Viscoelastic Matter
Valentin Slepukhin and Oskar Hallatschek
Growth is a fundamental process in living systems. Although the stress-deformation response of growing materials is often described as either purely elastic or purely viscous, many biological tissues, from biofilms to tumors, exhibit both elastic and viscous behavior. Here, we show that this viscoelastic response can crucially control the mechanics of proliferating matter when the growth rate becomes comparable to the rate of stress relaxation. Focusing first on the prototypical case of a growing elastic beam, we find that the dynamics are governed by a single dimensionless parameter, $g \tau$, where $g$ is the growth rate and $\tau$ is the viscoelastic relaxation time. While the limits $g \tau \to 0$ and $g \tau \to \infty$ recover purely viscous and purely elastic behavior, respectively, the intermediate regime is not merely a smooth crossover between them. Instead, qualitatively new dynamics emerge at $g \tau \sim 1$, including rapid transitions between metastable states that occur in neither limiting regime. We then develop a general, growth-compatible theoretical framework in which unconstrained growth is intrinsically stress-free, extending the analysis to other prototypical geometries and enabling simulations of more realistic growing biological materials. Within this framework, sharp mechanical transitions arise when stress generated by exponential growth accumulates faster than it can be dissipated by viscoelastic relaxation.
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Solar and Stellar Astrophysics
Stability of circumbinary orbits in misaligned triple star systems
Stephen Lepp and Rebecca G. Martin
We investigate the stability of circumbinary orbits in hierarchical triple
star systems, focusing on the effects of a misaligned outer companion
star. Test particles are subject to competing gravitational torques from the inner binary and the outer binary companion. With secular theory we estimate the outer radius of particle stability, where the torques balance. We find good agreement with $n$-body simulations across a wide range of triple
star configurations. Stable circumbinary orbits can exist even in strongly misaligned triples. Polar and highly inclined orbits with respect to the inner binary can remain stable over a substantial radial range, which is insensitive to the triple
star misalignment. Orbits that are close to coplanar or retrograde coplanar to the inner binary are more susceptible to instability when the mutual inclination between the binaries is large. These findings indicate that misaligned and polar circumbinary disks and
planets can survive in triple
star systems under a broad set of conditions. The analytic criterion identifies where stable material may exist, with implications for the formation and detection of circumbinary
planets in multiple-
star systems.
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