Physics and Society
Directed percolation in higher-order social dilemmas
Pablo Villegas and Sandro Meloni
Multiplayer social dilemmas on hypergraphs show a variety of emergent phenomena, which has been attributed to group interactions. Here we test whether pairwise dynamics can reproduce them as well. We derive the mesoscopic Langevin equation of a testbed model and find the operator content of absorbing phase transitions: a directed-percolation line, a tricritical point, and a first-order region whose spinodal is the explosive transition. In our analysis, three-player games only set the values of the Landau coefficients. We construct a strictly pairwise model with short-lived
memory, in which every event involves at most two entities, that reproduces these coefficients term by term and has exactly the same mean-field fixed points. Simulations confirm that the two dynamics share mean-field critical and tricritical scaling and the size of the critical mass, and that a purely three-player game on a two-dimensional triangular
lattice lies in the directed-percolation class. For these games, the explosive transition and the critical mass therefore do not require group interactions, and the critical behavior is that of the pairwise theory.
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Astrophysics of Galaxies
Black hole spin-mass correlation and accretion disks at birth stage of dense star clusters
Zacharias Roupas
We review the
accretion-driven channel of stellar black-hole growth and
spin-up in gaseous
star clusters, developed within the framework of our MSCA project "protoBH". Our detailed calculations involving semi-analytic modelling, dynamical and hydrodynamic simulations suggest that the growth and
spin-up of initially low-mass stellar black holes is an integral element of the formation process of dense massive
star clusters, such as the proto-globular clusters observed at high
redshift. The black holes accrete residual gas, remaining from the first
star formation event, and form
accretion disks generated by gas angular momentum induced by the black-holes' own curved orbits. Assuming initial black hole masses below the pair-instability mass gap $\leq 55\,{\rm M}_{\odot}$, the gap gets populated with black-hole masses growing to $\sim 10^2\,{\rm M}_{\odot}$, and even reaching several hundred solar masses for sufficiently dense and massive proto-clusters. We predict a consistent
spin-mass relation with low black hole
spins $\lesssim 0.2$ for low black hole masses $\lesssim 20\,{\rm M}_{\odot}$, spanning all intermediate
spins for higher masses and saturating to high
spins $\gtrsim 0.8$ for high masses $\gtrsim 70\,{\rm M}_{\odot}$. We find evidence in favour of such an
accretion-driven subpopulation of black holes in the GWTC-5.0 released by the LIGO-Virgo-KAGRA collaboration.
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Physics and Society
Social Norm Diffusion in Societies: Simple or Complex?
Claudia Lorenzetti, Aron Szekely, Daniele Vilone et al. (+1 more)
Social norms are a fundamental component of society, shaping how we communicate, cooperate, and avoid conflict. Despite their ubiquitous presence and profound influence on behaviour, questions remain about how they spread from person to person and whether they are adopted. Using an evolutionary game-theoretic model, we study whether simple or complex contagion processes characterise how social norms spread. Crucially, contagion type is endogenous and emerges from the model. We also vary cultural conformism, the cost of following a norm, and network
topology to assess the generality of our results. We show that social norms in our model can spread through simple contagion when a new norm is low in cost and cultural conformism is low, while norms spread through complex contagion when the new norm is costly and cultural conformism is high.
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All authors Claudia Lorenzetti, Aron Szekely, Daniele Vilone, Giulia Andrighetto
Statistical Mechanics
Macroscopic fluctuation theory of stochastic systems undergoing monitoring
João Costa, Pedro Ribeiro and Andrea De Luca
We develop a macroscopic fluctuation theory for diffusive classical
lattice gases subject to continuous coarse-grained monitoring. Treating measurements in the typical-outcome (quenched) regime, we show that observation adds a quadratic confining term to the MFT action that pins the density to its hydrodynamic profile. We derive sufficient conditions under which, in the presence of monitoring, the current large-deviation function remains convex, the additivity principle holds, and dynamical phase transitions are excluded. For particle-hole-symmetric one-dimensional models we find that monitoring suppresses dynamical phase transitions and can change their order from second to first, as we demonstrate in the Katz–Lebowitz–Spohn model. In the strong-measurement limit, we find that the current distribution becomes Gaussian and determine the scaling of its cumulants: they follow simple power laws when the mobility remains nonzero throughout the system, but exhibit anomalous logarithmic scaling when the mobility vanishes at the boundaries.
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Quantum Physics
Steering the Fidelity in State Preparation on Noisy Bosonic Systems with Risk-Seeking Optimization
Riccardo Piantoni, Riccardo Pellini, Maurizio Ferrari Dacrema et al. (+1 more)
In order to execute
quantum algorithms on bosonic
quantum computers, it is necessary to encode their inputs into a desired target
quantum state, with a process called state preparation. In real settings, state preparation methods operate in
stochastic scenarios, where the prepared state is represented as a mixed state, that is a probabilistic ensemble of pure states. Therefore, existing state preparation methods optimize a variational ansatz by averaging over all possible sequences of
photon loss events contained in the prepared ensemble, yielding an output state which approximates the desired target with a certain average fidelity. Such an approach, however, does not take into account directly the distribution of fidelities across states in the ensemble. In this work, we aim to maximize the fidelity of only a subset of pure states sampled from the prepared ensemble, at the cost of reducing the average fidelity overall. This trade-off is relevant when the goal is to obtain high-fidelity states with a certain probability, rather than maximizing the average fidelity of the prepared ensemble. We borrow and adapt objective functions from risk-sensitive optimization, a framework that optimizes specific characteristics of a distribution rather than only its expectation, and that has been successfully applied in Reinforcement Learning. In the considered experimental settings, our results show that the infidelities of some pure states in the prepared ensemble can be reduced by up to four orders of magnitude when using risk-seeking objectives, compared to those achieved using the standard optimization of the average fidelity. Furthermore, we show that it is possible to control the trade-off between the probability of obtaining high-fidelity states and the lowest infidelity threshold reached, providing the flexibility to select the operating point that best suits a certain application.
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All authors Riccardo Piantoni, Riccardo Pellini, Maurizio Ferrari Dacrema, Paolo Cremonesi
Materials Science
Quantitative Modelling of Solvation in 2D Materials via Alchemical Decoupling and Potential Energy Surfaces
Lindsey N. Ioos, Duncan A. Peterson and Scott C. Warren
Understanding why 2D materials remain suspended in solutions is essential to understanding the mechanisms of aggregation and exfoliation. These dynamics have been difficult to model because of the long timescales and large activation energies involved in these simulations. Here we describe an improved strategy for modelling the solvation and stability of 2D materials that uses the Gibbs free energy of solvation to accurately calibrate two disconnected potential energy surfaces for the fully desolvated and fully solvated 2D materials. By joining these surfaces using solvation energy, we obtain predictions for 2D material stability in various solvents that are qualitatively different than prior simulations and that have excellent agreement with experimental results. Our approach predicts a much higher barrier to full desolvation of the material, suggesting that materials that appear to be aggregated in fact still retain monolayers of solvent between adjacent layers of 2D materials. This work provides much needed understanding on the interactions between the solvent and 2D material that can guide future experimental work.
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High Energy Physics (Phenomenology)
Deviations to cobimaximal mixing in a 3+1 neutrino scenario
Diana C. Rivera-Agudelo and S. L. Tostado
Cobimaximal mixing remains a viable approximate pattern since the predicted atmospheric angle ($\pi/4$) and Dirac CP phase ($-\pi/2$) are compatible with current experimental data at the $3\sigma$ level. In this work, we investigate how an additional sterile
neutrino state breaks the cobimaximal mixing and the underlying $\mu-\tau$ reflection
symmetry in a $3+1$
neutrino scenario. Given the strong constraints already imposed on active-sterile mixings, we examine the resulting restrictions on the model parameter space, assuming a small
symmetry breaking induced by the sterile state. We derive predictions for the relevant model parameters, active-sterile mixing angles, and Dirac CP-violating phases, by considering small deviations from the symmetric limit. We also analyze the allowed combinations of Majorana phases through their impact on the effective Majorana mass governing neutrinoless double beta decay. Current experimental limits on this process impose severe constraints on the inverted ordering realization of the $3+1$ scenario, excluding the small breaking regime within the parameter ranges considered. In contrast, the normal ordering case remains viable and predicts values of the effective Majorana mass that lie within the sensitivity reach of upcoming neutrinoless double beta decay experiments.
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Mathematical Physics · Cross-listed from math.AP
Sign-indefinite transmission conditions and near-zero eigenvalues and resonances
Andrea Mantile and Andrea Posilicano
We consider the linear operator for metamaterial modeling $$L_{c,d }=(\chi_{\RE^{3}\backslash\overline \Omega}+c)\nabla\!\cdot (\chi_{\RE^{3}\backslash\overline \Omega}+d)\nabla\,,$$ where the material parameters $c>0$ and $d$ are constant on each connected component of the bounded domain $\Omega$, $d$ is negative on at least one component of $\Omega$ and transmission boundary conditions hold at the interfaces. It turns out that $L_{c,d }$ has, as in the sign-definite case, an absolutely continuous spectrum equal to $[0,+\infty)$; however, contrary to the latter, it has a non-empty point spectrum; in particular, we find conditions on the parameters so that zero is a threshold
eigenvalue. In the case $\Omega$ is connected, we study how such a threshold
eigenvalue behaves under $\varepsilon$-small analytic perturbations of the parameters. We show that, depending on the position of the number $\frac12\,\frac{1+d(\ve)}{1-d(\ve)}$ relative to the nearest
eigenvalue of the Neumann-Poincaré operator of the interface, the zero
eigenvalue splits into two branches (analytic in $\varepsilon^{1/2}$), consisting either of two branches of resonances, or of one branch of negative
eigenvalues and one of resonances.
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Quantum Physics
Lifting: Quantum State Discrimination Framework for Mid-Circuit Measurements
Chi Zhang, Neel Vora, Yilun Xu et al. (+3 more)
Quantum computing promises new capabilities beyond classical computation. Mid-
circuit measurements (MCMs) enable error correction and outcome-dependent control, but their reliability is limited by noise on superconducting hardware. These operations depend on accurate
quantum state discrimination (QSD), which assigns measured signals to state labels. Neural network-based (NN-based) QSD improves this assignment, yet its error remains bounded below by the Bayes risk of the available readout distributions. A complementary challenge is state deterioration as successive measurements accumulate and
circuit execution advances, making static calibration less representative of the workload. We present Lifting, a QSD framework that addresses both challenges through repetition encoding, neural decoding, and in situ calibration. Encoding supplies joint in-phase and quadrature (I-Q) readout signals from the target and auxiliary
qubits, while contextual calibration trains the decoder for the conditions encountered during execution. Our theoretical analysis shows that retaining additional channels from a fixed joint distribution cannot increase Bayes risk and establishes sufficient conditions for contraction of an overlap-based upper bound. Experiments across three IBM processors evaluate the framework on repeated stabilizer measurement, parity-check, and teleportation workloads.
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All authors Chi Zhang, Neel Vora, Yilun Xu, Gang Huang, Fan Chen, Lei Jiang
Cellular Automata and Lattice Gases · Cross-listed from math.GR
When do lazy and invertible cellular automata generate all cellular automata?
Edgar Alcalá-Arroyo and Alonso Castillo-Ramirez
Let $G$ be a group and let $A$ be a set with at least two elements. A lazy cellular automaton over $A^G$ acts as the identity except at the
cells where a fixed pattern occurs, where it replaces the central symbol by a fixed different symbol. Let $M(G;A)$ be the submonoid of $\mathrm{CA}(G;A)$ generated by the lazy and the invertible cellular automata. We study when $M(G;A) = \mathrm{CA}(G;A)$. Since no lazy cellular automaton is surjective, every surjective element of $M(G;A)$ is invertible; hence $M(G;A) \neq \mathrm{CA}(G;A)$ whenever $A$ is infinite or $G$ has an element of infinite order. Moreover, if $|A| = 2$ and $G$ has a quotient isomorphic to the Klein four-group $C_2 \times C_2$, then $M(G;A) \neq \mathrm{CA}(G;A)$. For locally finite $G$, and in particular for finite $G$, these are the only obstructions: we prove that $M(G;A) = \mathrm{CA}(G;A)$ if and only if $3 \leq |A| < \infty$, or $|A| = 2$ and $G$ has no quotient isomorphic to $C_2 \times C_2$.
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Quantum Physics
Experimental Realization of a C-Shunt Flux-Qubit Coupler for Controlled-Z Gates between Transmons
Weiping Yuan, Silu Zhao, Li Li et al. (+16 more)
Fast entangling gates and low-interaction idling require distinct operating conditions in superconducting
quantum processors. We experimentally realize a transmon-C-shunt-transmon (TCT) device in which a flux-tunable, three-junction capacitively shunted flux-
qubit coupler connects two transmon data
qubits. The C-shunt coupler provides a flux-tunable, positively anharmonic spectrum for tailoring the interactions between the data
qubits. Conditional Ramsey and swap measurements identify an idle region with near-zero residual ZZ interaction strength and suppressed transverse exchange. At this bias, simultaneous single-
qubit interleaved randomized benchmarking yields X-gate fldelities above 99.7%, consistent with individual operation. A 45 ns nonadiabatic controlled-Z (CZ) gate achieves an interleaved randomized benchmarking fldelity estimate of 99.23(15)%. Numerical simulations identify coupler energy relaxation as an important limitation on CZ-gate fldelity and indicate that extending the coupler lifetime can improve gate performance. These results demonstrate the experimental feasibility of C-shunt flux-
qubit couplers for combining low-interaction idling with fast entangling operations between transmon
qubits.
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All authors Weiping Yuan, Silu Zhao, Li Li, Chenglin Deng, Zhenghe Liu, Yu Liu, Tianming Li, Mingchuan Wang, Bingjie Chen, Guihan Liang, Jiacheng Song, Jinming Guo, Shuaili Wang, Mingxuan Zhou, Xiaohui Song, Kai Xu, Heng Fan, Zhongcheng Xiang, Dongning Zheng
High Energy Astrophysical Phenomena
Broadband non-thermal emission predictions based on 3D simulations of supernova explosions within active galactic nuclei jets
B. Longo, V. Bosch-Ramon, M. Perucho et al. (+1 more)
Thermonuclear and core-collapse
supernovae are statistically expected to happen within extragalactic jets, as these jets cross the inner regions of their host
galaxies, and
supernova ejecta-jet interactions can potentially lead to strong non-thermal activity. We model the non-thermal emission from a
supernova interacting with a jet on kiloparsec scales, using detailed numerical simulations of the interaction. Using a post-processing method, we applied a non-thermal model of the acceleration and transport of electron and their synchrotron and inverse Compton emissions, simplified and tuned for flexibility and computational speed, to the results of a three-dimensional relativistic hydrodynamics simulation of the ejecta of a
supernova interacting with an extragalactic jet. For intermediate jet powers,
radio, optical and X-ray fluxes from
supernova ejecta-jet interactions may be detectable for distances < 100Mpc. The non-thermal luminosity budget and local conditions associated with these interactions could be enough to explain
knots seen in kiloparsec scale jets at different energies. These conditions might also be suitable for the production of heavy ultra high-energy
cosmic rays, but
photon and
neutrino generation from hadronic processes would be minor on kiloparsec scales. The leptonic gamma-ray fluxes are modest but might non-negligibly contribute in TeV for the nearest or more powerful jet sources.
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All authors B. Longo, V. Bosch-Ramon, M. Perucho, J.M. Martí
General Relativity and Quantum Cosmology
Tidal Excitation of Relativistic Stars
Zhiqiang Miao, Junquan Su, Neev Khera et al. (+1 more)
How a relativistic
star responds to a time-dependent tide has lacked a first-principles counterpart of the Newtonian normal-mode expansion. In general relativity, the tidal field is gauge sensitive, radiative modes are non-Hermitian and incomplete, and the direct and late-time responses are intrinsically nonmodal. In this work we present, to our knowledge, the first causal relativistic theory that treats all of these components on equal footing. We first develop the spectral decomposition of the retarded Green function of the matched stellar interior–Schwarzschild exterior, which classifies four separate regimes in time domain: acausal region,
prompt wave, surface-reflected wave, and mode+tail. The
prompt signal is identical to that of a Schwarzschild black hole with the same mass, which is combined with the surface-reflected wave to be referred as the "direct part". With the Green function and a complex bilinear form on the full metric–fluid phase space, we decompose the linear response of a nonrotating perfect-fluid
star into direct, quasinormal-mode, and late-time-tail sectors. Crucially, every sector admits an explicit first-order driven
evolution equation: discrete bilinear projections determine the dynamically evolving quasinormal-mode amplitudes, while continuum projections of the same tidal source onto branch-cut states determine the direct and tail amplitudes. The result is a complete modal–nonmodal decomposition of the spacetime and fluid perturbations, which is physically described by the dynamics of a discrete and a continuous-frequency set of oscillators. We verify the decomposition numerically under generic time-dependent tidal driving and discuss applications to black hole perturbations.
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All authors Zhiqiang Miao, Junquan Su, Neev Khera, Huan Yang
Quantum Physics
Unequal Coherent Ergotropy at Equal Interferometric Visibility and Energy in Quantum-Controlled Interferometers
Tonipe Anuradha, André H. A. Malavazi, Borhan Ahmadi et al. (+2 more)
The ergotropy, or unitarily extractable work, of a
quantum system naturally splits into incoherent and coherent contributions, respectively set by population inversion and coherences in the energy eigenbasis. We show that this split makes the coherent ergotropy of a Mach–Zehnder
qubit sensitive to path predictability that the output interference fringes do not reveal. We send the path
qubit, prepared as a thermal
quantum battery, through two
quantum-controlled interferometers built from the same elements, a fixed beam splitter and a beam splitter coherently controlled to be present or absent, differing only in the order in which these two act. The two arrangements share identical visibility, stored energy, and incoherent ergotropy at every point in the parameter space. Yet, for work extracted from the output battery alone, placing the controlled beam splitter first never yields less coherent ergotropy, and at fixed visibility and interferometric phase the difference is governed by the path predictability that this ordering creates. The same expression reappears as a purity deficit on the beam-splitter controller, so the work advantage comes with a Landauer bound on the cost of locally resetting the controller that is never larger at the same temperature. We further examine the effects of decoherence on the battery and consider a relativistic realization in which a Wigner rotation correlates the particle's
spin with its path. Tracing out the
spin decoheres the battery and allows the two arrangements to exhibit different coherent ergotropies even in regimes where their non-relativistic counterparts coincide. These results show that interference visibility is not a complete measure of the coherence available as work.
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All authors Tonipe Anuradha, André H. A. Malavazi, Borhan Ahmadi, Lucas Pollyceno, Pedro R. Dieguez
Astrophysics of Galaxies
EDGE-INFERNO: The chemical signatures of assembly history in reionization fossils
Eric P. Andersson, Martin P. Rey, Alexander P. Ji et al. (+9 more)
In
galaxies, stellar populations represent a superposition of both in situ and accreted components, tracing internal chemical
evolution as well as the histories of merged satellites. We investigate how assembly history shapes the chemical properties of present-day stellar populations in low-mass dwarf
galaxies. We analyze a suite of EDGE-INFERNO
star-by-
star cosmological zoom-in simulations of
galaxies with present-day
halo mass $\sim1.4\times10^9\,{\rm M}_{\odot}$. We systematically vary
galaxy growth while preserving the present-day
halo mass, engineering our simulations to span a continuum of assembly histories. Early-forming systems form most of their
stars in a single progenitor, with centrally concentrated
star formation and a continuous enrichment history. In contrast, our late-forming systems assemble by
accretion of multiple progenitors with their own stellar populations, resulting in fragmented
star formation across several
halos with independent chemical
evolution tracks. These regimes produce qualitatively different chemical signatures: single-progenitor systems exhibit connected, well-defined trends in abundance space, while multi-progenitor systems show multiple, distinct stellar populations with limited overlap. We find that
metallicity distribution functions provide initial constraints on assembly history for samples of at least $50$-$100$ member
stars. Multi-element abundance analysis significantly improves the recovery of distinct components, although robust reconstruction still requires larger samples. Fully separating in situ and accreted populations likely requires kinematic information. Accreted
stars can contribute substantially even at high
metallicities in multi-progenitor systems, while external enrichment can cause accreted material to follow similar chemical trends as in situ
stars, particularly in the single-progenitor regime.
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All authors Eric P. Andersson, Martin P. Rey, Alexander P. Ji, Justin I. Read, Oscar Agertz, Alexander H. Riley, Stacy Y. Kim, Astha Chaturvedi, Jennifer Mead, Kaley Brauer, Mordecai-Mark Mac Low, Andrew Pontzen
Optics
Continuous-wave 148.4-nm generation in strontium tetraborate for nuclear absorption spectroscopy
Hanlin Wang, Zhouzhi Tan, Conghui Huang et al. (+13 more)
Continuous-wave light near 148.4 nm enables direct absorption spectroscopy of the thorium-229 nuclear transition. We demonstrate single-pass frequency doubling in strontium tetraborate, delivering an estimated 8.1 nW at 920 mW pump power. At this power, oxygen admission leaves a background of 1.22 kHz, corresponding to an estimated signal-to-background ratio of 3.8 x 10^4 after current-integration calibration. Several
crystals grown by top-seeded solution growth produce polarization-dependent VUV signals. Temperature scans reveal distinct maxima among specimens cut from one boule and among positions within a specimen. The source sustains operation over 33.3 h. In a separate 3-h record acquired with 1-ms gates, local referencing achieves near-Poisson averaging, reaching a fractional Allan deviation of 3.5 x 10^-5 at 1000 s. These results establish a practical VUV source for stable, long-duration spectroscopy of weak nuclear absorption.
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All authors Hanlin Wang, Zhouzhi Tan, Conghui Huang, Jinming Liu, Xuan Fan, Runzhe Yang, Meng Wang, Tung-Hsun Chung, Yong-Heng Huo, Yin Hang, Zhiwei Jiao, Heng Tu, Lei Zhang, Xu-Fei Yin, Pengfei Wang, Zhiqiang Zhang
Instrumentation and Methods for Astrophysics
Ushering in high angular resolution observatories in the far-infrared: The case for a double-Fourier interferometer
C. S. Benson, M. Bonato, T. A. Davis et al. (+14 more)
A far-infrared (far-IR) interferometer from a space-based platform would bring about a transformational improvement in the spatial detail of astronomical observations that are inaccessible from ground-based observatories. This orders-of-magnitude improvement would significantly advance studies of newly formed and mature exoplanetary systems and their potential for supporting life, the earliest stages of
star formation, and the
evolution of
galaxies up to the peak of the Universe's
star formation activity and beyond. In this work, we discuss the potential for such an instrument and the science it enables in complement to current long-term plans of the global astronomical community and in preparation for the next generation of observatories. We also outline notable far-IR mission concepts, pathfinder instruments, and technology development platforms that have been studied and developed throughout the past few decades and briefly discuss key enabling technologies.
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All authors C. S. Benson, M. Bonato, T. A. Davis, T. Essinger-Hileman, D. Farrah, W. Grainger, D. Leisawitz, H. Matsuo, B. Matthews, P. Pokorny, S. E. Ragan, B. V. Ricketti, G. Savini, J. P. Scott, L. D. Spencer, C. M. Urry, D. Wilner
Cosmology and Nongalactic Astrophysics
Constraints on the cosmic reheating history from PTA data
Qi-Lin Yang, Shi-Jie Wang and Nan Li
The
cosmic reheating is an important epoch in the very early Universe, and has significant impacts on the primordial black hole (PBH) abundance and the scalar-induced gravitational wave (SIGW) spectrum. The relevant energy scale and the constituents of
cosmic medium are encoded in the reheating frequency $f_{\mathrm{reh}}$ and the equation of state parameter $w$. In this work, we perform a full parameter space
Bayesian inference, using the NANOGrav 15-yr
dataset to constrain the thermal history of reheating. Treating $f_{\mathrm{reh}}$ and $w$ as free parameters, we systematically investigate the Dirac $\delta$, narrow and broad log-normal primordial power spectra. Current
pulsar timing array data can effectively constrain the peak frequency of the SIGW spectrum as $f_{\rm p}\sim 10^{-7.6}$–$10^{-7.0}$ Hz, along with $f_{\rm reh}\sim 10^{-9.0}$–$10^{-8.3}$ Hz and $w\sim 0.19$–$0.79$ (the $68\%$ confidence level), when the power spectrum has a relatively narrow width $\Delta \lesssim 1$. A broader power spectrum introduces a smoothing effect that obscures the characteristic frequency knee in the SIGW spectrum, leading to the loss of information about
cosmic reheating. Furthermore, for the Dirac $\delta$ and narrow spectra, the PBH masses associated with the SIGWs are anchored at the planetary mass scale around $10^{-6}$–$10^{-4} M_{\odot}$. This establishes a consistent physical framework that naturally bridges the nanohertz gravitational wave background with the dark matter candidates implied by the Optical Gravitational
Lensing Experiment microlensing events.
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High Energy Physics (Phenomenology)
HEPTABench: A framework for portable and controlled agentic evaluations in high energy physics
Tony Menzo, Alexander Roman, George T. Fleming et al. (+3 more)
Quantifying the capability and reliability of agentic systems in high-energy physics (HEP) requires repeated evaluations under controlled configurations. Establishing whether changes to models, tools, or harnesses improve performance also requires these components to be varied independently. We present the High Energy Physics Tool-and-
Agent Benchmarking (HEPTABench) framework for portable and controlled evaluations of agentic systems, with separately configurable tasks, scaffolding, models, providers, harnesses, and domain capabilities. The framework combines HEP
benchmark tasks and scientific rubrics with experiment execution and versioned tool interfaces. To support inspection, reproducibility, and post-hoc grading, the framework prioritizes recording and reporting complete experiment specifications,
agent trajectories, and experiment artifacts. We demonstrate the framework in two
benchmark campaigns. The first campaign evaluates a forward long-lived-particle reach calculation across four frontier coding-
agent systems, comparing their built-in coding tools with the same tools supplemented by HEP domain tools. We show that including these HEP domain tools improves numerical accuracy and reduces trial-to-trial dispersion for every tested system. In a complementary campaign covering eight symbolic two-body decay tasks, we show that adding symbolic domain tools increases the fraction of successful trials for Claude Haiku 4.5 from $8\%$ to $79\%$, while GPT-5.5 succeeds in every trial with built-in tools alone. Through systematic evaluation of agentic systems, HEPTABench enables the identification of factors that improve the accuracy and reliability of their scientific work.
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All authors Tony Menzo, Alexander Roman, George T. Fleming, Sergei Gleyzer, Konstantin Matchev, Stephen Mrenna
High Energy Physics (Theory)
Giant Graviton Expansions from Symmetric Functions and Free Fermions
Min-xin Huang
Giant graviton expansions express finite-rank corrections to supersymmetric indices in terms of indices for wrapped D3-branes. We give detailed algebraic proofs of two previously proposed relations for four-dimensional $\mathcal N=4$ $U(N)$ super-Yang–Mills theory. The first is the Gaiotto–Lee single-sum expansion of the full superconformal index, proved by Hall–Littlewood orthogonality and an elementary calculation of operator traces. The second is the symmetric double-sum expansion of the flavored Schur index, proved by factorizing its exact free-
fermion mode product. We specify the analytic continuation of the brane indices and justify the sums coefficient by coefficient. The two proofs apply to different expansion prescriptions and do not establish the full three-species expansion of Imamura. We discuss the additional physical and mathematical questions raised by that expansion and by the modular properties of the Schur index.
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Materials Science
Substrate-controlled epitaxial-like growth of photochromic yttrium oxyhydride thin films
M. Zubkins, E. Strods, E. Letko et al. (+7 more)
Yttrium oxyhydride (YHO) thin films are synthesised by reactive magnetron sputtering of e̱ta}-YHx precursor films onto single-crystalline yttria-stabilised zirconia (YSZ) (111) and (100) substrates at 200 {\deg}C, followed by post-deposition oxidation in air. For comparison, reference films are also prepared on amorphous SiO2 and soda-lime glass substrates at both 200 {\deg}C and room temperature (RT). The structural (X-ray diffraction and scanning electron microscopy), compositional (elastic recoil detection analysis), and optical properties, including photochromic behaviour, of the films are systematically investigated. The results reveal a strong influence of substrate orientation on the film microstructure and crystallographic texture, leading to epitaxial-like growth with a mosaic spread of ~3-4{\deg}. YHO deposited on YSZ(100) exhibits larger crystallite sizes (10-20 nm) than YHO grown on YSZ(111) (~8 nm) and exhibits residual in-plane compressive strain while remaining largely relaxed with respect to the substrate. Compositional analysis revealed that the O/Y and O/H atomic ratios ranged from 0.71 to 0.82 and from 0.33 to 0.44, respectively, for films deposited under optimised conditions. These films exhibit photochromic behaviour under solar simulator illumination, with relative transmittance changes ranging from 7 to 22 % after 10 min of illumination. Despite the pronounced structural differences, the epitaxial-like films show no systematic improvement in photochromic response, indicating that the effect is governed primarily by composition. The study shows that the bleaching time constant increases exponentially with increasing contrast reached during illumination, rather than representing an intrinsic material constant of YHO.
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All authors M. Zubkins, E. Strods, E. Letko, H. Mändar, D. Moldarev, K. Mizohata, K. Sarakinos, V. Vibornijs, K. Kundzins, J. Purans
Strongly Correlated Electrons
Altermagnetic Ground States on the Ammann–Beenker Tiling
SeungBeom Hong, YunHo Kim, Moon Jip Park et al. (+1 more)
We identify exact altermagnetic ground states of a classical Heisenberg model on a quasicrystal. Considering the Ammann–Beenker tiling as an example, we determine the ground states by exploiting the parity structure of its parent four-dimensional hypercubic
lattice. The ground state hosts coplanar altermagnetic order characterized by the preserved
spin-group
symmetry $[C_{2x}\parallel C_{8z}]$. Without translational
symmetry, the momentum-space
spin splitting that usually identifies altermagnets is not directly accessible. We instead couple the
spins to itinerant electrons and show
spin-resolved transport with $g$-wave
symmetry, confirming the altermagnetic nature in a nonperiodic system. Our results establish a
geometric route to altermagnetic order in quasicrystals, connecting exact
magnetic ground states to their
spin-resolved transport signatures.
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All authors SeungBeom Hong, YunHo Kim, Moon Jip Park, GiBaik Sim
Mathematical Physics · Cross-listed from math.PR
A Central Limit Theorem for High-Temperature SYK Model
Yoshinori Kamijima, Shuta Nakajima, Ryoichiro Noda et al. (+1 more)
The Sachdev–Ye–Kitaev (SYK) model is a
quantum many-body model of Majorana
fermions with all-to-all random interactions. It has attracted wide interest in condensed matter and high-energy physics as a solvable model of non-Fermi
liquids and holography. Fix an even integer $q\geq4$, and let $Z_N(\beta)$ be the partition function of the Gaussian $q$-body SYK model. We prove that for all sufficiently small inverse temperatures $\beta > 0$, there exists $\rho=\rho(\beta)>0$ such that \[ N^{q/2 -1}(\log Z_N(\beta)-\mathbb{E}[\log Z_N(\beta)]) \Longrightarrow \mathcal{N}(0,\rho^2). \] In addition to the mathematical results, we discuss how the proofs were developed and refined through interaction between human researchers and AI, and we describe the subsequent formalization of the main arguments in Lean 4. This work thus serves as a case study of a research workflow that integrates human insight, AI-assisted exploration, iterative proof refinement, and formal verification.
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All authors Yoshinori Kamijima, Shuta Nakajima, Ryoichiro Noda, Kôhei Sasaya
Mathematical Physics · Cross-listed from math.PR
Stability of the Markov-Krein Transform Under Classical Convolutions
Pierre Mergny
We prove that, for every $c>0$, the image of the generalized Markov-Krein transform on probability measures with finite logarithmic moment is closed under classical additive convolution and under the Mellin convolution. This resolves the positivity
conjecture for the additive high-temperature convolution, a one-parameter interpolation between classical and free convolution arising in random
matrix theory and representation theory in the regime $N\to\infty, N\beta_N/2\to c$. Our proof relies on a convolution
theorem for universally prestarlike functions.
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High Energy Astrophysical Phenomena
Delving into the depths of NGC 3783 with XRISM VI. Evidence for a failed wind based on Fe xxv absorption line variability
Chen Li, Jelle S. Kaastra, Liyi Gu et al. (+7 more)
NGC 3783 exhibits a prominent Fe XXV absorption trough in the time-averaged XRISM/Resolve spectrum. To investigate its short-term variability, we present a time-resolved analysis of the Fe XXV absorption line during the continuous 10-day observation. We divided the resolved absorption profile into five fixed velocity intervals and measured their normalized equivalent widths in 19 time-resolved spectra. Three velocity intervals exhibit significant equivalent-width (EW) variability. Two velocity intervals respond differently to low- and high-flux states with less emission line contamination. The time-dependent photoionisation modelling is unable to reproduce the most significant observed EW variation ($3.5 \, \sigma$), possibly owing to uncertainties in the assumed initial
equilibrium state, which prevent a precise density measurement. Instead, using photoionisation calculations and assuming the high-density limit, we derive approximate constraints on the ionisation parameters of the two relevant components. The low-velocity component (-320 to -680 km/s) shows a delayed inverse response, indicating a high ionisation parameter, while its relatively short lag timescale indicates a relatively high density and a distance upper limit of 0.05 pc. In contrast, the high-velocity component (-680 to -1040 km/s) manifests a positive response with a longer lag to the ionising continuum, implying a relatively low ionisation parameter. This component appears to be less dense, with an inferred distance upper limit of 0.25 pc. The low-velocity component is consistent with a failed wind, as its outflow velocity is below the local escape velocity, whereas the high-velocity component lies near the escape threshold. Together with the lower-ionisation failed wind detected in 2001, this supports a multiphase failed-wind scenario in the unobscured state of NGC~3783 over more than two decades.
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All authors Chen Li, Jelle S. Kaastra, Liyi Gu, Missagh Mehdipour, Keigo Fukumura, Matteo Guainazzi, Misaki Mizumoto, Ehud Behar, Shoji Ogawa, Keqin Zhao
Mathematical Physics
Spectral Theory of an Exactly Solvable Quantum-Optical Oscillator
Sam Johar and Joseph Kraisler
We study a one-dimensional single-excitation model of a scalar
photon field coupled to a continuum of two-level atoms with quadratic density. The resulting
matrix Hamiltonian has an unbounded spatially varying coupling and is not semibounded. We prove that it is essentially self-adjoint and determine its spectrum explicitly. The continuous spectrum is the half-line $(-\infty,\Omega]$, where $\Omega$ is the atomic resonance frequency, while the spectrum above $\Omega$ consists of a strictly increasing sequence of simple
eigenvalues. These
eigenvalues are characterized by the interlaced zeros of the Airy function and its derivative and satisfy \begin{align*} \omega_n = \left(\frac{3\pi g n}{4}\right)^{1/2} + \frac{\Omega}{4} + O(n^{-1/2}). \end{align*} The analysis is based on a nonlinear spectral reduction that yields a confining massless relativistic oscillator above $\Omega$ and an inverted oscillator below $\Omega$.
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Superconductivity
The role of dependency range in thermally coupled superconducting networks
Nahala Yadid, Bnaya Gross, Shlomo Havlin et al. (+1 more)
Interdependent networks can be highly fragile because dependency links amplify local failures into cascades that trigger global collapse. Much of the theoretical understanding comes from
geometric network models, where dependency range is imposed externally and coupling strength is distance independent, and it is unclear how these insights apply to real materials, where interdependence arises from physical transport. Here we study thermally coupled amorphous superconducting networks, in which dependencies emerge from current redistribution and heat-mediated interactions governed by thermal diffusivity. Using an experimentally calibrated model of resistively shunted Josephson junctions, we show the system reproduces the three canonical transition regimes: continuous, nucleation-dominated, and mixed-order. However, because heat-driven dependency simultaneously broadens and weakens with distance, long-range thermal coupling can stabilize the superconducting phase upon heating, in contrast with its destabilizing role in
geometric models. Cascades are anisotropic, with one-dimensional front propagation. These results offer an experimentally testable perspective complementing the
geometric framework.
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All authors Nahala Yadid, Bnaya Gross, Shlomo Havlin, Nadav M. Shnerb
Soft Condensed Matter
Curie-Weiss cell fluid model: Fitting to experimental critical-point data
I.V. Pylyuk, O.A. Dobush, M.P. Kozlovskii et al. (+2 more)
We examine how the Curie–Weiss
cell fluid model can be quantitatively related to real fluids by determining its microscopic parameters from experimental critical-point data for water, carbon dioxide, and three polyol ester lubricants (POE5, POE7, and POE9). The microscopic parameters of the model are determined from the experimental values of the critical temperature and critical density: the global attraction coupling constant is fixed by the critical temperature, and the
cell volume by the critical density. The critical pressure then follows as an independent model prediction, deviating from experimental values by 10–41$\%$ across the studied substances. Varying the ratio of local repulsion to global attraction $f=J_2/J_1$ over a wide range has only a weak effect on this deviation. For $f\geq1$, the model's critical compressibility factor lays within a narrow range $Z_c\approx0.382-0.386$, remaining close to the mean-field van der Waals value $Z_c=3/8=0.375$ and consistently overestimating experimental values. The best agreement with experiment is obtained for the polyol ester lubricants and improves along the POE5–POE7–POE9 series with increasing molar mass, suggesting that multiple-occupancy
cell fluid models are well suited to systems of large molecules, particularly soft-matter systems with bounded interaction potentials. We further show that generalizing the model by introducing a temperature- and phase-dependent effective attraction allows it to describe a triple point and to reproduce the broad range of critical-to-triple temperature ratios $T_c/T_{\mathrm{tr}}$ characteristic of real fluids.
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All authors I.V. Pylyuk, O.A. Dobush, M.P. Kozlovskii, R.V. Romanik, M.A. Shpot
Optics
Orbital Angular Momentum Transfer and Beam-Quality Limits in Fork-Grating Electron Diffraction
P.K. Tsiopa and S.S. Baturin
We analyze fork-grating generation of electron
vortex beams beyond the ideal single-mode approximation. The incident beam is described as a paraxial Gaussian ensemble with finite transverse momentum spread and a first electromagnetic Hartree phase accumulated before the grating. Within Fresnel propagation we derive an analytical expression for each diffraction order and determine the corresponding orbital-angular-momentum statistics. The mean OAM of a selected order remains fixed by the topological rule, $\langle L_z\rangle_m=mp\hbar$, while its variance is set by the residual transverse momentum spread of the beam prepared at the grating. For the Gaussian mixture, the transverse purity is $\mathcal P_{\perp,m}=[1+2(\Delta L_{z,m}/\hbar)^2]^{-1}$. The observed annular profile is governed by a separate propagation-dependent blurring scale, so a beam can retain well-defined mean OAM while having low transverse purity or a partially filled
vortex minimum. Within the radial phase-screen approximation, the Hartree self-field modifies the propagated profile while preserving the full-plane OAM moments and transverse purity.
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Accelerator Physics
Phase Memory Controls Radiative Depolarization Near an Isolated Spin Resonance
Zhe Duan
Radiative depolarization near
spin resonances in electron storage rings is conventionally described by correlated-sideband and local resonance-density theories, but a quantitative description of the crossover between them has remained lacking. Here we derive a unified finite-
memory response from
stochastic spin dynamics near an isolated resonance. By separating the coherent resonance contribution from
stochastic fluctuations, we show that the connected correlation of the accumulated resonance-relative
spin phase determines the leading off-center weak-resonance depolarization rate. Both conventional theories emerge as controlled asymptotic limits of this response, which also captures the surviving synchrotron phase
memory governing the crossover. Monte Carlo
spin tracking validates the predicted rates throughout the crossover and reproduces the recurrence-induced generalized-sideband structure. More broadly, the connected-correlation formulation provides a basis for extending radiative depolarization theory to more general
stochastic spin-orbit dynamics in storage rings.
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