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Physics

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Tuesday 11 August

Instrumentation and Detectors

Cusp-singularity-enhanced Coriolis effect for ultrasensitive chip-scale gyroscopes

Sen Zhang, Dingbang Xiao, Fei Wang et al. (+8 more)

Gyroscopes, as fundamental inertial sensors, are crucial for rotation measurements in consumer electronics, automotive, and aerospace industries, with the most widely used kind relying on the Coriolis effect. The chip-scale Coriolis vibratory gyroscopes (CVGs) show reduced size, weight, and cost, but remain far lower performance than traditional macroscale CVGs, as the weak intrinsic Coriolis factor sets a fundamental limit on scaling the sensitivity against the inherently louder Brownian noise in microchips compared to the macroscale ones. Here, to overcome this physical limit, for the first time, we propose and experimentally demonstrate the use of third-order singularities lying within cusp catastrophes in the phase-tracked oscillations of an on-chip CVG to facilitate a cubic-root scaling of the Coriolis-effect-induced frequency modulation. Employing this effect, we achieve a three-order-of-magnitude enhancement in the Coriolis factor, yielding a 253-fold improvement in signal-to-noise ratio and a 297-fold increase in precision. Moreover, the cusp singularity enables a previously unattainable ultrasensitive phase-modulated sublinear measurement, achieving a world-record signal-to-noise ratio performance for silicon-chip gyroscopes. These findings not only provide revolutionary advancements in gyroscope technologies, by filling the gap in observing and controlling the singularity-enhanced Coriolis effect, but also shed new light on other ultrasensitive sensing applications.
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All authors Sen Zhang, Dingbang Xiao, Fei Wang, Ran Huang, Lei Yu, Ning Zhou, Kaixuan He, Xuezhong Wu, Franco Nori, Hui Jing, Xin Zhou

General Physics

Constraints on the Modified Emergent Dark Energy Model Using DESI DR2 BAO

Himanshu Chaudhary, Dhruba Jyoti Gogoi, Salvatore Capozziello et al. (+1 more)

In this work, we investigate the modified emergent dark energy (MEDE) model using baryon acoustic oscillation measurements from the Dark Energy Spectroscopic Instrument Data Release 2 (DESI DR2), together with CMB information from the LoLLiPoP (low-$\ell$) and HiLLiPoP (high-$\ell$) likelihoods based on the latest Planck NPIPE PR4 release, Planck PR4 lensing, ACT DR6 lensing, and three Type Ia supernova samples (Pantheon$+$, DES-Dovekie, and Union3). We find that the MEDE model remains largely consistent with the standard $\Lambda$CDM cosmology. Although small departures from $\Lambda$CDM are allowed, the inclusion of SNe~Ia data drives the model parameters toward the standard cosmological scenario, with the parameter $\alpha$ remaining consistent with $\alpha=0$ at the $1\sigma$ level. The model does not significantly alleviate the $H_0$ or $S_8$ tensions: the inferred $H_0$ values remain below the SH0ES measurement, the sound horizon $r_d$ is nearly unchanged, and the predicted $S_8$ values remain close to those of $\Lambda$CDM. The reconstructed cosmological evolution closely follows the $\Lambda$CDM prediction, with deviations generally below the $0.5\sigma$ level. While the CMB + DESI DR2 dataset favors a full phantom regime, the inclusion of SNe~Ia shifts the evolution toward a full quintessence regime. Finally, although the $\Delta\chi^2_{\rm MAP}$ and $\Delta{\rm AIC}$ criteria indicate a marginally better fit than $\Lambda$CDM, the logarithmic Bayes factor provides only inconclusive evidence in favor of the MEDE model. Overall, the MEDE model remains compatible with current observations but does not exhibit the phantom-crossing behavior suggested by recent DESI DR2 analyses.
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All authors Himanshu Chaudhary, Dhruba Jyoti Gogoi, Salvatore Capozziello, G. Mustafa

General Physics

Emergent Space, Time, and Lorentz Symmetry from Binary Sequences

Sam Powers and Dejan Stojkovic

We construct an information theory framework in which the fundamental objects are binary sequences of length $n$, equipped with the bitwise XOR operation. The only physical observables are counts of XOR-generated symbol classes, while the exact locations of symbols are inaccessible. Averaging over those locations ultimately yields the Minkowski interval as an invariant object that maximizes (information) entropy. Correlations between two binary sequences are base-4 sequences that we label as “events”, and events are connected with maps. The entire kinematic structure of Special Relativity is recovered under minimal assumptions, i.e. counts that represent space and time increments carry equal informational weight. The central claim is that Lorentz symmetry is the typical large-n behaviour of XOR counting. At finite $n$ the framework yields a discrete rapidity spectrum, a bound $\gamma_{\max} = O(\sqrt{n})$, and interval fluctuations of relative size $O(n^{-1/2})$, with standard special relativity recovered as $n \to \infty$. However, the light cone and one null coordinate are exact for every microscopic configuration, so the symmetry group is undeformed and dispersion relations are unmodified. Thus, the theory, though discrete, implies no Lorentz violation of the standard phenomenological kind. Ultra-high-energy cosmic rays already require $n \gtrsim 10^{23}$; interferometry excludes the variant in which $n$ scales linearly with system size, leaving a holographic area law. The most striking prediction of the framework concerns systems at the maximum of their information capacity, where $n$ is necessarily finite: black holes and de Sitter space. There the corrections are of order one within a Planck proper length of the horizon, regardless of the horizon's size, and the spacetime description fails altogether at the endpoint of black-hole evaporation, where $n$ itself is of order unity.
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General Physics

Observational constraints on Barrow holographic dark energy coupled with a non-cold dark matter component from DESI DR2

Abdulla Al Mamon, Genly Leon, Subhajit Saha et al. (+1 more)

We investigate the cosmological viability of Barrow holographic dark energy in a spatially flat Friedmann–Lemaître–Robertson–Walker universe in which the dark matter component is allowed to have a non-zero pressure, characterized by a constant equation-of-state parameter $w_{m}$. By considering the future event horizon as the infrared cutoff, we derive the master equation, which describes the cosmological dynamics for the background space. We constrain the model against late-time data, combining the baryon acoustic oscillation from DESI DR2 with three different catalogues for the Type Ia Supernova measurements and the Cosmic Chronometers. The dark matter equation of state is constrained to $w_{m}=0.033_{-0.030}^{+0.045}$, $0.009_{-0.041}^{+0.047}$, and $0.033_{-0.029}^{+0.042}$, for the PantheonPlus, the Union3.0 and the DES-Dovekie supernova datasets respectively. Therefore, the pressureless limit is recovered within the $2\sigma$ regime. On the other hand, the Barrow exponent is weakly constrained, due to the $\Delta-w_{m}$ degeneracy. The dark energy equation of state remains above the phantom divide throughout the redshift range probed. Finally, in the comparison of the statistical parameters with that of $\Lambda$CDM, it follows $\Delta\mathrm{AIC}=+2.23$, $+0.75$, and $+1.38$, $\ $while for the Bayesian evidence we find $\Delta\ln Z=-0.63$, $+0.47$, and $-0.13$, which suggest that the datasets considered in this analysis do not have a preferred model. Finally the relation with the corresponding Tsalis holographic dark energy model is discussed.
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All authors Abdulla Al Mamon, Genly Leon, Subhajit Saha, Andronikos Paliathanasis

Instrumentation and Detectors

Compact nondestructive generator for microsecond-class ultrafast pulsed magnetic fields

Y. Ishii, A. Ikeda, H. Sun et al. (+2 more)

The sweep rate of pulsed magnetic fields is a key factor in exploring of nonequilibrium phenomena in matter. However, the nondestructive generation of ultrafast pulsed magnetic fields is challenging because of the large time constants associated with the large inductance and capacitance of conventional pulsed magnetic field generators, as well as the residual inductance of the power devices and the system itself. We have developed a new compact pulsed magnetic field generator using commercially available state-of-the-art ultrafast power devices, enabling the generation of ultrafast pulsed magnetic fields up to approximately 1 T with a pulse duration of 3.8 $\mu$s. We present the performance of the newly developed system and compare the experimentally obtained magnetic field waveforms with the results of a simple circuit simulation. In addition, we demonstrate magnetization measurements on cobalt powder and Faraday rotation measurements on CdS single crystal using the developed system.
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All authors Y. Ishii, A. Ikeda, H. Sun, H. Oike, Y. H. Matsuda

Chaotic Dynamics

Flux-form spatiotemporal neural operators for coarse-grained dynamics of multiscale PDEs

Junfeng Chen

We study data-driven prediction of coarse-grained dynamics in multiscale PDE systems. Adopting a closure-free operator-learning viewpoint, we apply a linear coarse-graining map and learn a surrogate evolution operator for the resolved field directly from filtered high-fidelity trajectories. Motivated by the Mori-Zwanzig formalism, we propose a spatiotemporal neural operator mapping a resolved history slab on $\Omega\times[-T_{\mathrm{in}},0]$ to a resolved future slab on $\Omega\times[0,T_{\mathrm{out}}]$. Spatial mixing uses Fourier convolution, while temporal mixing uses a causal kernel operator with position-attention weights on time lags. This causal temporal operator encodes finite-memory effects in the resolved dynamics while preserving the directionality of the history-to-future map. To improve rollout robustness and suppress nonconservative artifacts, we embed a flux-form inductive bias by parameterizing the windowed update in explicit divergence form. We also provide a data-driven guideline for selecting the memory length $T_{\mathrm{in}}$ via the decorrelation time of a closure-injection diagnostic computed from filtered trajectories. We validate on the coarse-grained viscous Burgers' equation, the Kuramoto-Sivashinsky equation, and two-dimensional turbulent flows, obtaining stable autoregressive rollouts with improved long-horizon accuracy and statistical fidelity.
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Quantum Physics

A formal correspondence between Bayesian inference problems and the Heisenberg representation

C. Abugattas Chacoff

The proposed formulation establishes a formal correspondence between the Heisenberg representation and the Bayesian formulation of inverse problems. The likelihood function is first expressed in Hilbert space through a quadratic norm of the difference between the noisy observations and the response of a forward model depending on the unknown parameters, weighted by the inverse of the observational noise covariance. Based on the common mathematical structure of this quadratic form and the observable operator in the Heisenberg representation, the inverse observational noise covariance operator is identified with the initial observable. To establish this correspondence, a stochastic field with Matérn covariance is considered and represented through the Karhunen-Loève expansion. The eigenvalues and eigenfunctions of this expansion are then used to define the state $|\Psi\rangle$ within the proposed formalism. The main results are summarized by four theorems: the unitarity of the evolution operator, the self-adjointness of the Hamiltonian, the conservation of the trace of the observable, and the formal correspondence between the Bayesian likelihood and the Heisenberg observable structure. Limiting cases of the Matérn covariance are analyzed. Finally, numerical examples illustrate the analytical results.
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Quantum Physics

QSimAdv: A Late-Bound, Vendor-Agnostic Architecture for High-Performance Quantum-Circuit Simulation

Shusen Liu, Pascal Jahan Elahi, Wenyun Sun et al. (+3 more)

Portability in high-performance quantum-circuit simulation need not begin at the kernel. We present QSimAdv, which makes late binding, rather than a common kernel, the basis of vendor independence. Representation, operator lowering, and data placement are bound only when their required inputs become available. Before full-state allocation, circuit, noise, and output inspection can route eligible generic sampled-count requests to a stabiliser tableau; explicitly requested representations remain fixed. For full-state execution, backend constraints shape fusion; an ordered fused operator binds to a native lowering only after its physical targets are known. A first-class logical-to-physical layout map records non-canonical order across local and rank-address bits, so the dispatcher moves nonlocal targets only on demand. GPU, CPU, and Message Passing Interface (MPI) backends share these semantics while retaining native execution paths. We realize this design on NVIDIA GH200 and AMD MI250X/EPYC systems across local and distributed execution. With matched complex 32-bit floating-point state storage, QSimAdv leads both Aer Hopper configurations at $N=32$ and Aer's HIP backend at four shared MI250X sizes from $N=24$ to 30. Strong scaling exposes platform dependence: on setonix, QSimAdv leads both GPU and CPU comparisons at every measured rank, achieving $3.4\times$ and $2.8\times$ speedups, respectively, from one to eight ranks; neither the GH200 path nor the CPU path speeds up at eight ranks. Weak scaling reaches 256 ranks with 2 TiB GPU and 1 TiB CPU states. Together, these results support that portability can reside above the kernel boundary while execution remains native and extends across distributed memory.
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All authors Shusen Liu, Pascal Jahan Elahi, Wenyun Sun, Shenjin Lv, Xiaohan Shan, Ugo Varetto

Quantum Physics

SPSA Hyperparameter Tuning for Variational Quantum Natural Language Inference

Nayan D'Souza and Christopher J. Agostino

Training variational quantum models requires choosing between parameter-shift gradients, which are exact but cost $O(P)$ forward evaluations, and simultaneous perturbation stochastic approximation (SPSA), which uses only two samples but produces high-variance estimates that can degrade optimisation on small supervised tasks. Whether the cheap gradient is usable depends on the variance that results from different choices of the SPSA perturbation scale, learning rate, and gain-decay schedule. We varied those quantities across a broad grid on a 6-qubit, 60-parameter QNLI classifier and compared the best configurations to parameter-shift AdamW and BuresQNG. AdamW-style SPSA with $c_0=0.01$, $\eta=0.10$, $\gamma=0.10$ reached $55\% \pm 11\%$ test accuracy, improving over the default configuration ($49\% \pm 6\%$) but remaining 16-19 percentage points below the parameter-shift baselines because the two-sample SPSA gradient estimate has too much variance for reliable optimisation of 60 parameters in 40 epochs. Classical-gain SPSA and Bures-preconditioned SPSA performed worse, at $51\%$ and $46\%$ respectively. Bures-preconditioning a noisy two-sample SPSA gradient amplifies perturbation noise.
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Plasma Physics

Data-Driven Generation of Compact Quasi-Isodynamic Stellarators

Yang Han, Hanlin Chen. Shuai Cao, Zhiyuan Lu et al. (+3 more)

Stellarator design explores a vast space of three-dimensional plasma boundaries, only a small fraction of which yields usable equilibria. Data-driven models can narrow this search by learning from existing optimized configurations. Building on the ConStellaration database, we extend conditional boundary generation to four-field-period QI configurations, focusing on the sparsely sampled low-aspect-ratio regime. The approach learns the common geometric structure of known QI equilibria and then adapts it using a small high-fidelity compact dataset, allowing target magnetic properties to guide generation beyond the original data distribution. This adaptation reduces the compact-domain test loss by approximately 87% and yields converged ultra-compact candidates consistent with the prescribed conditions. Several candidates show favorable confinement indicators, and one provides a useful seed for further QI optimization and finite-beta assessment. The method therefore serves as a data-informed front end to high-fidelity physics and optimization.
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All authors Yang Han, Hanlin Chen. Shuai Cao, Zhiyuan Lu, Dehong Chen, Guosheng Xu, Baonian Wan

Data Analysis and Statistics

Exploring new directions in enhancing the ACTS parameter optimization suite

Chance LaVoie, Qi Bin Lei, Rocky Bala Garg et al. (+1 more)

Track seeding strongly affects both the quality and computational cost of charged-particle reconstruction, yet its many configuration parameters are commonly tuned through expert intuition and repeated trial and error. ACTS reduces this burden with an Optuna Tree-structured Parzen Estimator auto-tuner, but expensive evaluations, a restricted search space, and a scalarized objective can limit evaluation efficiency, exclude promising configurations, and obscure performance trade-offs. We investigate whether Bayesian optimization can address these limitations using ACTS with the Open Data Detector (ODD). Under identical search ranges and a common 100-trial budget, we compare Expected Improvement and Upper Confidence Bound with TPE and random search on the existing eight-parameter problem, extend the best-performing Bayesian method to fifteen parameters, and apply Expected Hypervolume Improvement to optimize efficiency, fake rate, duplicate rate, and runtime without fixed scalar weights. Candidate configurations are evaluated through the full ACTS reconstruction chain and validated on disjoint held-out events. The Bayesian acquisition methods identify strong configurations earlier than TPE, and their advantage persists in held-out validation. Expanding the search further improves performance, while multi-objective optimization reveals competitive non-dominated solutions spanning distinct trade-offs. These results indicate that Bayesian optimization can strengthen ACTS auto-tuning through efficient evaluation, broader parameter searches, and post-hoc expert selection among non-dominated alternatives.
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All authors Chance LaVoie, Qi Bin Lei, Rocky Bala Garg, Lauren Tompkins

Lattice Field Theory

Blind Spots of the Zwanziger Horizon Function

Daniel G. Tedesco

We examine the configurationwise relation between the first Gribov horizon, defined by loss of positivity of the Faddeev-Popov operator, and Zwanziger's horizon function, which probes the inverse operator through background-dependent sources. The analysis focuses on whether the spectral directions associated with the onset of the Gribov horizon are necessarily accessible to the sources entering the horizon function, including situations in which the critical subspace is degenerate. This question is studied for radial SU(2) hedgehog backgrounds in three and four Euclidean dimensions, where angular symmetry constrains the source sector while the radial profile controls the ordering of Faddeev-Popov thresholds. Variational estimates and finite-volume calculations are used to characterize the threshold structure for smooth radial profiles. The regular-gauge BPST background is treated separately because of domain issues associated with zero-energy behavior and the horizon source in the full-space setting. The discussion is restricted to configurationwise spectral properties and does not address the statistical weighting of these backgrounds in the Yang-Mills functional integral.
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General Relativity and Quantum Cosmology

On Super-Hyperbolic Wormhole Geometries and their Deformations

Subrat Parida

In this study, we developed a unified geometric and relativistic framework for a new family of traversable wormholes constructed from a super-hyperbolic deformation of the classical catenoid, whose geometric embedding combines an explicit local curvature parameter $\kappa$, which secures a regular throat, with the Mittag-Leffler-based super-hyperboloid deformation function ${\mathfrak{S}C}_{\alpha} (v)$, where the deformation parameter $\alpha>1$ governs the radial onset and far-field growth of the embedding beyond the throat, continuously approaching the classical catenoidal geometry in the boundary limit $\alpha\rightarrow1^{+}$. Allowing a non-constant redshift $\Phi(r)$, we systematically evaluate closed analytical expressions for the shape function, curvature tensors, matter sources, and junction conditions, culminating in an exact thin-shell equation of motion and stability criterion. This work establishes a mathematically consistent and physically viable framework for the extension of wormhole theory, providing a new avenue for exploring exotic geometries within general relativity and identifying the conditions under which traversable configurations remain locally stable.
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Mesoscale and Nanoscale Physics

Quantum-Geometric Bound on Dynamical Instability in Bosonic Systems

A.M. Tishin

Quantum-geometric speed and dynamical instability are two natural rates for a driven quantum system, and their relation is unsettled even for exactly solvable dynamics. Here we show that for any multimode quadratic bosonic system referred to the bare-mode vacuum the Fubini-Study speed v_FS is the Frobenius norm of the symmetric, stretching part of the flow: the rate at which the vacuum becomes distinguishable from itself measures instantaneous symplectic stretching. That identity turns a classical stability estimate into a quantum-geometric bound, lambda_max <= sqrt(2) v_FS, sharp at every mode number and saturated by a resonant pure squeezer. The bound is not invertible: in a detuned parametric amplifier we hold either rate fixed while varying the other.
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General Relativity and Quantum Cosmology

Effects of Quantum Spin-Connection Foam in the Solar System, Galaxies, and the Universe

Igor V. Kanatchikov and Valery A. Kholodnyi

We argue that effects of the quantum spin-connection foam, which describes quantum gravity according to the precanonical quantization of General Relativity, may already be observed in the form of the small cosmological constant and a modification of Newtonian dynamics at small accelerations, manifested in the flat rotation curves of galaxies. We obtain a modification of the Newtonian potential that takes into account the existence of a fundamental small acceleration scale, $a_* = 8\pi G\hbar\varkappa$, where $\varkappa$ is a parameter with the dimensions of inverse spatial volume that appears on dimensional grounds. The connection between $\varkappa$ and the hadronic scale of the mass gap in the pure Yang-Mills sector of the Standard Model leads to an estimated value of $a_*$ compatible with the Milgromian acceleration scale in MOND. The connection between $a_*^2$ and the cosmological constant leads to a realistic value of the latter. Milgromian MOND, together with a theoretically distinct interpolating function, is derived under the assumption that classical dynamics is modified by the mean-field acceleration calculated from the simplest solution of precanonical quantum gravity in the nonrelativistic approximation. We also indicate that the effects of Newtonian dynamics modified by the spin-connection foam may be observable in the Solar System and even in laboratory experiments.
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2608.12404 · 11 Aug · 17 pages. To appear in: The Seventeenth Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Astrophysics, and Relativistic Field Theories, Pescara 7-12 July 2024, edited by G. Vereshchagin and R. Ruffini, https://doi.org/10.1142/14814, October 2026. Corrects typos in eqs (26), (29) in the published version, adds refs [64-66]

Abstract PDF $QNTM ×4$SPIN ×3$GLXY ×2$GRAV ×2 +1

Statistical Mechanics

A piston-like polymer stochastic heat engine

Yi-Jui Chiu and Cheng-Hung Chang

Colloidal stochastic engines are often regarded as microscopic analogues of macroscopic pis ton cylinder heat engines. However, although they share some underlying physical principles, such systems remain far from being direct force generators from a practical perspective. Motivated by this limitation, the present study introduces a polymer-based stochastic engine that more closely mimics the operation of piston cylinder engines. In this setup, heat is converted into work through a cyclic process in which a polymer is pulled into and out of a narrow channel under varying tem peratures. The work performed by the engine can be directly obtained from the cyclic trajectory in the force position diagram, analogous to the pressure volume diagram in traditional heat engines. Despite its much higher number of degrees of freedom compared to colloidal engines, the polymer en gine nevertheless follows several characteristic features observed in such systems. Numerical results demonstrate consistency with universal low-dissipation bounds for e ciency, recovery of Carnot e ciency under regeneration, and low-dissipation scaling of work and power.
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Astrophysics of Galaxies

Chemistry here and there: Comparison between the CMZ of the Milky Way and NGC 253

Sergio Martín, Álvaro López-Gallifa, David San Andrés et al. (+2 more)

For decades, chemical studies in external galaxies have been limited by sensitivity, resolution, bandwidth or a combination of them. A decade of ALMA operations, made the detailed study of the molecular abundances in nearby galaxies a routine job. We can finally bridge the ISM chemistry from Galactic to extragalactic environments, through one to one comparison, albeit probing significantly different scales. The ALMA large program ALCHEMI imaged the chemistry of the starburst galaxy NGC 253 at an unprecedented combination of sensitivity and resolution, achieving a detailed spatially resolved chemical inventory. ALCHEMI probed molecular differences among regions within its CMZ, and allowed the comparison with Galactic environments ranging from hot cores, quiescent molecular clouds and comets. This comparison can be put in the context of available data towards other extragalactic environments. Globally, the comparisons presented here show an astoundingly good correlation between the chemistry in Galactic GMCs and the central molecular zone of NGC 253, ranging scales from 1 pc up to ~0.5 kpc. The wideband sensitivity upgrade of ALMA will expand similar comparisons towards a wider range of Galactic and extragalactic objects.
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All authors Sergio Martín, Álvaro López-Gallifa, David San Andrés, Victor Rivilla, ALCHEMI Collaboration

Quantum Physics

Orbit-resolved spectra and dynamical accessibility in multi-register covering Hamiltonians

Fabricio de Souza Luiz

Which part of a Hamiltonian spectrum is relevant when the initial state and interpolation preserve multiple symmetries? We study this question for a multi-register encoding of fixed-cardinality Set Cover. Register permutations and incidence automorphisms define a joint action whose orbits are unlabelled candidate covers, with an exact hopping Hamiltonian on the orbit quotient. We distinguish the symmetry-fixed space from the generally smaller common invariant cyclic envelope generated by the initial state and endpoint Hamiltonians; a prescribed trajectory may span less still. We prove a sector-resolved Schur-complement bound on cover-measurement probability that includes the kinetic floor induced by sector projection. For a retained-walk linear path, a general hopping-cancellation point makes the spectrum exactly orbit-resolved. Multiplicity outside the fixed sector is then dynamically dark, while transverse dark crossings satisfy a separate stability theorem. On even cycles the fixed-sector excitation gap at cancellation equals $\lambda(n-1)/(2n-1)$ despite global multiplicity closure. Separately, for the same instances, we construct a distinct Johnson–Metropolis parent path on the injective hard-core space, from a Dicke state to a Gibbs-amplitude state. Its cover-failure probability is $O(n^{-5})$ and its cyclic-envelope gap is at least $1024\,n^{-13}$ uniformly along the path, yielding a conditional polynomial adiabatic runtime in an abstract Hamiltonian-access model. We claim no quantum speedup; the result is a protocol-dependent separation of global, symmetry-fixed, cyclic-envelope, and tracked spectra.
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2608.11503 · 11 Aug · 20 pages, 2 figures, 4 tables. Revised version clarifies cyclic-envelope versus schedule-dependent reachability; adds a full-Hamiltonian sector-localisation audit, explicit comparison of two protocols, expanded literature positioning, exact-cardinality conventions, and archived code/data at https://doi.org/10.5281/zenodo.22142799. Main asymptotic theorem unchanged

Abstract PDF $HAML ×5$SYMM ×3$AUTOM ×1$PLYN ×1 +2

Quantum Physics

Exchange Fluctuation Theorems for Non-Markovian Baths in Quantum Collisional Model

Sayan Mondal, Sukrut Mondkar and Ujjwal Sen

The quantum exchange fluctuation theorem relates the probabilities of observing heat transfer along and against the temperature gradient between thermal baths at different temperatures. We investigate how this relation generalizes when the baths exhibit non-Markovian dynamics. Using a microscopic collisional model, bath memory is generated through interactions between successive bath auxiliaries before each heat-exchange collision. We derive exchange fluctuation theorems for both direct bath-bath interactions and probe-mediated heat exchange in the steady-state regime. As an illustrative example, we consider heat baths with qubit auxiliaries and show that non-Markovian memory enhances the probability of heat-transfer events against the temperature gradient, modifying the predictions made by the conventional Jarzynski-Wójcik exchange fluctuation theorem. Our results establish a microscopic connection between environmental memory and non-equilibrium heat-exchange statistics.
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Materials Science

Advances and opportunities for automated robotic preparation of 2D materials and fabrication of 2D heterostructures

S. Davari, D. L. Duong, T. Faltermeier et al. (+7 more)

The mechanical exfoliation, transfer, and stacking of 2D atomic sheets from van der Waals crystals synergize to enable atomic layer-by-atomic layer engineering of 2D heterostructures with tailored properties that yield new exotic phenomena and states of matter. With the huge variety of van der Waals materials available, there is a limitless number of ways to couple 2D semiconducting, insulating, magnetic, metallic, topological, etc. systems with one another. Experimental exploration of this vast space starts with the fabrication of high-quality 2D heterostructures, which is commonly performed manually, relying on humans to execute delicate operations. Many scientific advancements have been achieved in this manner, revealing immense potential for further discovery and innovation of increasingly sophisticated 2D heterostructures. However, soon, the complexity of the 2D heterostructures that define the scientific state-of-the-art will exceed the capabilities of manual fabrication. Therefore, the demand for robotic instruments for preparing 2D materials and fabricating complex 2D heterostructures with greater quality, at higher rates, and with better reproducibility is increasing. This review covers recent scientific, instrumentation, and processing advances rising to this challenge. Robotic instruments for mechanical exfoliation, optical metrology of 2D crystallites, stacking, as well as advancements in supporting technologies such as organic-free stamps, vacuum-compatible processing tools, and artificial intelligence (AI) are covered. Looking forward, a new generation of AI-driven, automated advanced manufacturing tools is anticipated to emerge from these current advancements. These new tools will bridge the current state-of-the-art of 2D heterostructure science to new scientific frontiers defined by precision fabrication of high-quality, complex, many-layer 2D heterostructure systems.
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All authors S. Davari, D. L. Duong, T. Faltermeier, J. A. Goss, A. Hasani, D. Kotekar-Patil, J. Peabody, S. Wyss, H. O. H. Churchill, N. J. Borys

High Energy Physics (Theory)

Spin(N) Magnetic Quivers

Mohammad Akhond, Sam Bennett and Amihay Hanany

This work introduces new magnetic quivers for $5\mathrm{d}$ $\mathcal N=1$ Spin(N) gauge theories with hypermultiplets in spinor representations at both finite and infinite coupling. Among them are new 3d $\mathcal{N}=4$ theories whose Coulomb and Higgs branches are isolated symplectic singularities, or a product of such spaces. These theories further expand the set of orthosymplectic quiver gauge theories whose Coulomb branch is a single isolated singularity, termed `minimal quivers'. Wreathings and foldings thereof realise quivers for non-simply laced nilpotent orbit closures.
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Materials Science

Soft-Phonon-Driven Effective Inversion-Symmetry Crossover in Quantum Paraelectrics

Xiaojiang Li, Guodong Zhao, Fei Yang et al. (+6 more)

Symmetry lays the foundation of condensed matter physics and its experimental manifestation provides fundamental insight into the collective behaviors of quantum materials. Optical second-harmonic generation (SHG) is widely regarded as a fingerprint of inversion-symmetry breaking, yet whether and how collective lattice dynamics govern the nonlinear optical manifestation of local inversion-symmetry breaking remains unknown. Here, combining optical SHG, diffuse X-ray scattering, and microscopic theory, we reveal a phonon-regulated mechanism governing the temperature-dependent manifestation of local inversion-symmetry breaking in quantum paraelectric material KTaO3. We demonstrate that an oxygen-defect-mediated nonlinear optical channel is strongly coupled to the host soft polar mode, whose thermal fluctuations scramble the associated electronic phase coherence and thereby suppress the nonlinear manifestation of local inversion-symmetry breaking at elevated temperatures. Consequently, the nonlinear response exhibits a temperature-driven crossover from a regime in which local inversion-symmetry breaking is optically manifest to one that appears effectively centrosymmetric, without any accompanying structural change. Our findings revise the conventional picture of the temperature-dependent manifestation of inversion-symmetry breaking in quantum paraelectrics and establish a framework for understanding and engineering defect-mediated nonlinear optical responses in materials hosting low-energy polar excitations.
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All authors Xiaojiang Li, Guodong Zhao, Fei Yang, Seng Huat Lee, Richard D. Schaller, Jong-Woo Kim, Matthew Krogstad, Long-Qing Chen, Philip J. Ryan

Soft Condensed Matter

Spatially heterogeneous relaxational dynamics and the evolution of recoverable strain following flow cessation of a ductile nanocolloidal glass

Chloe W. Lindeman, James J. Griebler, Penelope Grace Kovakas et al. (+6 more)

We report a combined rheology and x-ray photon correlation spectroscopy (XPCS) study of the structural and mechanical relaxation of a ductile, nanocolloidal glass following the cessation of shear flow. After the glass is sheared to 300% strain at various shear rates and then held at fixed strain, the stress undergoes a protracted, quasi-logarithmic decay with hold time that depends weakly on the initial strain rate. Recovery rheology measurements reveal that this stress relaxation is accompanied by a logarithmic decrease in the elastic component of the recoverable strain; hence, the rates of decrease of the stress and recoverable strain are proportional. XPCS measurements during the stress relaxation reveal dynamics dominated by a convection-like backflow that is divided into two dynamically distinct regions indicative of banded motion. In one region, the flow can be modeled by an affine strain, while in the other region the glass moves as a plug while undergoing slow, glassy relaxation. The rates of these dynamics approximately track the rate of loss of recoverable strain, indicating this motion is the predominant microscopic mechanism driving the conversion of recoverable to unrecoverable strain during stress relaxation. In contrast, XPCS measurements during strain recovery reveal purely affine flow with no evidence of heterogeneity and with strain rates that agree quantitatively with the rheometry measurements. Together, these results provide a unified microscopic picture connecting the evolving internal dynamics of a ductile glass to its macroscopic mechanical relaxation following flow cessation.
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All authors Chloe W. Lindeman, James J. Griebler, Penelope Grace Kovakas, Miaoqi Chu, Qingteng Zhang, Suresh Narayanan, James L. Harden, Simon A. Rogers, Robert L. Leheny

Nuclear Experiment

First measurement of polarized spin-density matrix elements and differential cross sections d$\sigma$/d$t$ in $\omega$~photoproduction off the proton for $2.7 < E_\gamma < 5.2$ GeV using CLAS at Jefferson Lab

T. Hu, Z. Akbar, V. Crede et al. (+147 more)

We report on the differential cross sections d$\sigma$/d$t$, the unpolarized spin-density matrix elements $\rho^0_{00}$, $\rho^0_{1-1}$, Re\,$\rho^0_{10}$, and the first extraction of the polarized elements Im\,$\rho^3_{10}$, Im\,$\rho^3_{1-1}$ for the reaction $\gamma p\to p\omega$ using the CLAS spectrometer at Jefferson Laboratory. The $\omega$~mesons were detected in their dominant charged decay mode, $\omega \to \pi^+\pi^-\pi^0$, and all $t$-dependent results are presented in a fine binning for incident photon energies between 2.73 and 5.16~GeV (corresponding to the center-of-mass energy range $W \in [\,2.45,3.25\,]$~GeV). All matrix elements are first measurements for $-t > 0.6$~GeV$^2$. Moreover, differential cross sections d$\sigma$/d(cos\,$\Theta_{\rm \,c.m.}^{\,\omega}$) and the corresponding angle-dependent unpolarized spin-density matrix elements in the Adair frame are presented for the incident photon energy range 1.56–3.80~GeV (corresponding to $W \in [\,1.95,2.83\,]$~GeV). These new $\omega$~photoproduction data are consistent with earlier CLAS results but extend the energy range well beyond the nucleon resonance region into the Regge regime. The comparison with Regge-theory-based model predictions shows that the new data impose more stringent constraints on our understanding of $\omega$~photoproduction.
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All authors T. Hu, Z. Akbar, V. Crede, J.M. Laget, V. Mathieu, M.J. Amaryan, W.R. Armstrong, H. Atac, N.A. Baltzell, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, L. Biondo, A. Biselli, M. Bondi, F. Bossù, S. Boiarinov, W.J. Briscoe, S. Bueltmann, D. Bulumulla, V.D. Burkert, R. Capobianco, D.S. Carman, J.C. Carvajal, A. Celentano, T. Chetry, G. Ciullo, G. Clash, P.L. Cole, M. Contalbrigo, G. Costantini, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, S. Diehl, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, S. Fegan, A. Filippi, G. Gavalian, Y. Ghandilyan, G.P. Gilfoyle, F.X. Girod, A.A. Golubenko, G. Gosta, R.W. Gothe, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, M. Hattawy, T.B. Hayward, D. Heddle, A. Hobart, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, K. Joo, S. Joosten, D. Keller, A. Khanal, M. Khandaker, A. Kim, W. Kim, F.J. Klein, V. Klimenko, A. Kripko, V. Kubarovsky, V. Lagerquist, L. Lanza, M. Leali, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, L. Marsicano, V. Mascagna, M.E. McCracken, B. McKinnon, Z.E. Meziani, S. Migliorati, R.G. Milner, T. Mineeva, M. Mirazita, V. Mokeev, C. Munoz Camacho, P. Nadel-Turonski, K. Neupane, J. Newton, S. Niccolai, M. Nicol, G. Niculescu, M. Osipenko, A.I. Ostrovidov, P. Pandey, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, S.J. Paul, W. Phelps, N. Pilleux, O. Pogorelko, J.W. Price, Y. Prok, B.A. Raue, T. Reed, M. Ripani, J. Ritman, A. Rizzo, G. Rosner, F. Sabatié, C. Salgado, S. Schadmand, A. Schmidt, R.A. Schumacher, E.V. Shirokov, U. Shrestha, P. Simmerling, D. Sokhan, N. Sparveris, S. Stepanyan, I.I. Strakovsky, S. Strauch, R. Tyson, M. Ungaro, L. Venturelli, H. Voskanyan, A. Vossen, E. Voutier, D.P. Watts, X. Wei, M.H. Wood, B. Yale, M. Yurov, N. Zachariou, J. Zhang

Materials Science

Accurate Evaluation of Nanoscale Spatiotemporal Dynamics with Electron Correlation Microscopy

Po-Cheng Kung, Ajay Annamareddy, Mark D. Ediger et al. (+2 more)

Electron correlation microscopy (ECM) can measure materials dynamics with nanoscale spatial resolution from intensity correlation functions. However, adopting X-ray photon correlation spectroscopy (XPCS) normalization frameworks unchanged when calculating intensity correlations can introduce errors. Due to the constrained sampling volumes and larger speckle sizes in nanobeam electron diffraction, XPCS-style time-averaging and scattering-vector averaging introduce systematic artifacts, such as artificial anticorrelations or elevated baselines that lead to systematic errors in structural relaxation times and stretching exponents. This work presents physics-inspired, ECM-specific intensity normalizations over time- and azimuthal-averaged intensities of the first diffraction ring that limit those errors. The framework is validated using molecular dynamics simulations of a CuZr supercooled liquid to benchmark against the self intermediate scattering function, successfully reproducing relaxation times. When applied to experimental time-resolved 4D STEM datasets of a Pt57.5Cu14.7Ni5.3P22.5 nanowire, the method correctly identifies highly stable, unchanging nanoscale crystalline phases that were erroneously misclassified as relaxing domains by previous frameworks. Other previous ECM research is reevaluated in light of these observation. This robust approach establishes an artifact-free pathway for evaluating localized spatiotemporal relaxation behaviors.
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All authors Po-Cheng Kung, Ajay Annamareddy, Mark D. Ediger, Dane Morgan, Paul M. Voyles

Fluid Dynamics

Influence of Flow on Discharge Behaviors and CO2 Conversion in Gliding Arc Discharges

Alexander Davis, Charles Burton, Stephanie Pecaut et al. (+4 more)

Plasma reactors present themselves as a unique means of electrified chemical production, particularly in the conversion of greenhouse gases (e.g., CO2) back into chemical feedstocks. Warm plasmas, such as gliding arc discharges, represent a growing class of catalyst-free plasma reactors that demonstrate high energy efficiency and scalability. Here, we introduce mean discharge time as a characteristic descriptor of gliding arc dynamics, extracted directly from voltage and current waveforms. Electrical signatures for distinct plasma behaviors (modes) were established using high-speed photography, and discharge time distributions were evaluated as a function of Reynolds number. Mean discharge time is shown to decrease non-linearly with Reynolds number, providing a link between arc behavior and underlying fluid dynamics, which is otherwise neglected in traditional reactor characterization. Mean discharge time thereby provides a quantitative, operando descriptor of transient gliding arc dynamics and stability, offering insight into discharge behavior that traditional characterization approaches do not capture.
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All authors Alexander Davis, Charles Burton, Stephanie Pecaut, Matthew Hershey, Michelle M. Driscoll, Linsey C. Seitz, Dayne F. Swearer

Mathematical Physics

Inverse characterization and non-uniqueness of the Gaussian configurational partition function

Ignacio S. Gomez

Given a configurational partition function, in this work we investigate the inverse problem of reconstructing the one-dimensional potential. For the case of the Gaussian partition function, the configurational density of states (CDOS) is univocally determined, being the harmonic potential uniquely recovered due to its symmetric single–well feature. When multiples inverse branches are considered, the uniqueness of the potential is broken and more information is needed in order to obtain a unique potential. The branch topology imposes alternating orientations, thus allowing distinct spatial realizations. Finally, the Gaussian partition function only determines the CDOS but not the potential, manifesting in this way the precise scope and limitations of the inverse characterization of the Gaussian configurational partition function.
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General Relativity and Quantum Cosmology

Investigation of Circular Photon Orbits in Naked Singularity Spacetimes from a Geometric Method

Qing-Rong Xie and Chen-Kai Qiao

Circular photon orbits play a pivotal role in both gravitational theories and astronomical observations. However, the properties of circular photon orbits in naked singularity spacetimes remain insufficiently explored and deserve in-depth investigation. The present work is dedicated to a comprehensive study of the features of circular photon orbits in naked singularity spacetimes. Notably, a geometric approach is employed to investigate these orbits, in which the framework of optical geometry together with its intrinsic curvatures plays a crucial role. We analyze the existence of circular photon orbits through the intrinsic geodesic curvature, and then examine the numbers of stable and unstable circular orbits, as well as the topological invariant associated with circular photon orbits. By examining various classes of naked singularity spacetimes, we obtain a general conclusion regarding circular photon orbits that holds for the most of spherically symmetric naked singularity spacetimes: the total number of circular photon orbits is an even integer ($\textit{N} = \text{2}\textit{k}$), consisting of $\textit{k}$ stable orbits and $\textit{k}$ unstable orbits in equal proportion. A mathematical proof of this conclusion is also provided in the present work. Furthermore, a comparison with other categories of spacetimes reveals that the conclusions regarding the number of circular photon orbits in naked singularity spacetimes agree with those obtained for compact object spacetimes without naked singularities, indicating that the number of circular photon orbits is primarily governed by the presence of event horizons rather than spacetime singularities. Keywords: Circular Photon Orbit, Naked Singularity Spacetime, Optical Geometry, Geometric Curvatures
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Mathematical Physics

Finite nonlinear mathematical structures induced by the Tsallis $q$-sum

Ignacio S. Gomez

The Tsallis $q$-sum is one of the fundamental nonlinear composition laws of nonextensive statistical mechanics. Although it has been extensively investigated in continuous settings, its implications for finite mathematical structures remain less explored. Here we investigate this question by replacing ordinary additive laws with the Tsallis $q$-sum. We first introduce an axiomatic $q$-cardinality of finite sets satisfying a nonlinear additivity principle. Existence and uniqueness are established, leading to an explicit expression that continuously recovers the classical cardinality as $q\to1$. We then propose a nonlinear matrix composition induced by the same deformation and establish its principal algebraic properties, including associativity, the neutral element, and a characterization of its noncommutativity in terms of the ordinary matrix commutator. An illustrative example over $M_2(\mathbb Z_6)$ shows how the deformation can modify the center of a finite matrix algebra when $1-q$ is a zero divisor. These results indicate that the Tsallis $q$-sum provides a natural mechanism for constructing nonlinear finite mathematical structures and connects nonextensive statistical mechanics with finite algebra and nonlinear mathematical physics.
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General Relativity and Quantum Cosmology

Torsional pseudo-inflation beyond Einstein-Cartan

Fernando Izaurieta, Samuel Lepe and Cristian Quinzacara

Torsion entered early-universe cosmology twice: through the nonsingular Einstein–Cartan bounce, where the quantum spin of fermions halts the contraction, and through the proposal that the expansion following that bounce could take over the duties of cosmic inflation. We revisit the second idea in a constructive spirit. First we compute its budget: for a Weyssenhoff spin fluid with barotropic source, $w\in\left[0,1\right]$, the accelerated window that follows the bounce spans $N_e=\ln\left[4/\left(1+3w\right)\right]/3\left(1-w\right)\leq\tfrac{1}{3}\ln4\simeq0.46$ e-folds, and positive spatial curvature only shrinks it. The mechanism is sound; its torsional “fuel” dilutes as $a^{-6}$, and the engine stops two orders of magnitude short of inflationary needs. We then ask what torsion would need in order to sustain a quasi-de Sitter phase, and give a two-branch answer in Riemann–Cartan cosmology with nonminimal couplings, where torsion is fed by the couplings rather than by spin. The vectorial branch reproduces Palatini inflation, observationally alive. On the axial branch we exhibit an exact de Sitter solution sustained by a torsion condensate: constant axial torsion $f_{0}$, a linear Gauss–Bonnet coupling, and a potential fixed to $V_{0}=6f_{0}^{2}+\tfrac{5}{2}v^{2}$ by the Friedmann constraint. The solution is an attractor of the homogeneous dynamics, with eigenvalue exactly $-3H$. The phase ends when the slope $U^{\prime}$, a decreasing function of the roll speed at fixed flat potential, drifts down to the floor $5/16V_{0}$ and the condensate switches itself off; consistency of the effective theory pins the whole episode near the Planck scale, $H\gtrsim0.3$ in reduced Planck units. We studied this branch at background level; its perturbation spectrum remains open.
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