Mathematical Physics · Cross-listed from math.CA
Hypergeometric Mixed-Type Multiple Orthogonal Polynomials
Manuel Mañas
Two hypergeometric families of mixed-type multiple orthogonal forms are constructed for rank-one $q\times p$
matrices of weights, with arbitrary $p$ and $q$: Jacobi and Laguerre I systems. Both normalized mixed forms are obtained explicitly for admissible near-diagonal multi-indices. The power-vector components are terminating generalized hypergeometric
polynomials, while the hypergeometric-vector components are finite sums of such
polynomials. In the Jacobi case, these sums are expressed as finite combinations of terminating Kampé de Fériet
polynomials evaluated at $(x,1)$. For the mixed beta–Euler Laguerre I system, a finite triangular system relates the residues at finite poles to the terms generated by the Euler operator. Gamma-quotient Mellin formulas, Meijer $G$-representations, and Rodrigues formulas are derived for the complete mixed forms. On the step-line, the two biorthogonal systems satisfy dual recurrences governed by
matrices with $p$ subdiagonals and $q$ superdiagonals. All recurrence coefficients are given by finite Gamma–Pochhammer expressions. Under normality and nonvanishing-pivot assumptions, Christoffel transformations and Gauss–Borel factorization yield bidiagonal factorizations of the recurrence
matrices. The lower factors have closed Pochhammer formulas, while the upper factors are expressed through finite Christoffel tau-determinants or, equivalently, cross-ratios of shifted moment minors. Both Christoffel chains close explicitly in the mixed Piñeiro specialization.
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Instrumentation and Methods for Astrophysics
Gram-Schmidt correlation bookkeeping for weighted FBET-type frameworks: separating short- and long-range correlation scales in correlated measurements, with an application to radio luminosity functions
Marko Imbrišak and Krešimir Tisanić
Uncertainty quantification for correlated measurements frequently requires a covariance model that mixes several qualitatively different correlation structures: local measurement noise, short-range (e.g. cyclic or seasonal) correlations, and long-range correlations associated with trend, drift, or long-
memory behavior. Weighted and generalized least squares can encode such structure only when the covariance
matrix is known or credibly specified in advance, which in practice it rarely is. We describe a structured correlation bookkeeping construction intended for use inside a weighted FBET-type (wFBET) uncertainty-quantification framework: candidate correlation basis functions associated with distinct lag variables are orthogonalized with a weighted Gram-Schmidt procedure (under an explicitly declared, statistically motivated metric) before they are allowed to enter the covariance or metric construction. This avoids the double counting inherent in naive additive covariance decompositions of the form $\Sigma = \Sigma_{\mathrm{short}} + \Sigma_{\mathrm{long}}$. We
benchmark the construction (in its vectorized form, its operator-valued kernel form, and the finite-rank basis-function realization used by the implementation) on the classic AirPassengers
benchmark dataset, and we apply it to the astrophysical case of
radio luminosity functions measured in
redshift bins. No claim of universal optimality is made; the goal is a transparent and auditable way to organize correlation scales within weighted information-
geometric fitting frameworks.
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Geophysics
CHERT: Cached Hamiltonian-Enhanced Ray Tracing in Viscoelastic Anisotropic Media
Muhammad F. T. Darwis, Fateh Bouchaala, Umair Bin Waheed et al. (+1 more)
Three sentence novelty statement: CHERT decouples the g
Hamiltonian ray quantity computation from field scale shortest path ray tracing through reusable directional caches. The cache is indexed by wave mode, class, and sampled ray direction, and provides ray velocity, attenuation, and direction during trajectory updates without repetitive
Hamiltonian evaluations. Controlled comparisons against MSPM demonstrate qP and qSH raypaths and traveltime fields consistency, qSV path selection sensitivity, and significant computational time reduction, while the angular coverage and nodewise
benchmark test validates the CHERTs computational performance.
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All authors Muhammad F. T. Darwis, Fateh Bouchaala, Umair Bin Waheed, Mohamed Kamel Riahi
Mathematical Physics
Dipesh Bhandari
Let $\Omega\subset\mathbb R^2$ be a bounded domain whose boundary $\gamma$ is a smooth simple closed curve, and let $r=|B|^{-1}$ be the Larmor radius of a constant
magnetic field. Assume $$ 0<r<\frac{r_0(\gamma)}2, $$ where $r_0(\gamma)$ is the maximal embedded tubular radius of $\gamma$. We prove that if the corresponding
magnetic billiard admits a nonconstant first integral
polynomial in the velocity, then $\gamma$ is a circle and $\Omega$ is a disk. No convexity assumption is imposed. This eliminates the finite set of possible exceptional strong-field values left by the earlier
polynomial nonintegrability theory. The proof uses the two highest reflection modes of the
polynomial induced on the space of Larmor centers. A boundary index identity shows that the highest coefficient has degree equal to the true
Fourier degree and that all of its roots lie inside the table. After complexification and passage to the normalization of the boundary curve, comparison of the two leading modes at infinity excludes simultaneous poles of the coordinate functions and forces all of these roots to coincide. The reflection identity then implies that the boundary has constant distance from their common root and hence is circular.
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Adaptation and Self-Organizing Systems · Cross-listed from q-bio.MN
Slow fluctuations shape cell signaling near a bifurcation in embryonic stem cells
Fiorella Fabris, Dhruv Raina, Christian Schröter et al. (+1 more)
Excitable and oscillatory responses are widespread in
cell signaling, but how these arise in the same system is unclear. We propose a minimal model of a saddle node bifurcation on an invariant circle, where slow fluctuations modulate transitions between excitable and oscillatory states, and noise drives excitability. Fitting the model to
cell signaling data from embryonic stem
cells reveals that these
cells operate close to the bifurcation. Proximity to the bifurcation allows the
cell to tune different dynamic states, suggesting a general principle for versatile
cell signaling.
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All authors Fiorella Fabris, Dhruv Raina, Christian Schröter, Luis G. Morelli
Fluid Dynamics
Generalised Perturbed Convective Wave Theory
Stefan Schoder, Eman Bagheri, Hugo Vincent et al. (+1 more)
The theory of the perturbed convective wave equation for compressible flows (cPCWE) is generalised to spatially varying mean-density fields. The resulting equation is an exact scalar reformulation of the acoustic perturbation equations and describes sound generation and propagation in moving inhomogeneous media using a single unknown. The intermediate variables of the associated workflow, in which a Helmholtz decomposition problem, a Poisson equation and the cPCWE are solved successively, are related to the vortical,
entropy and acoustic modes of Kovasznay, providing a physical interpretation of each processing step. The quantitative accuracy is assessed against fully compressible direct numerical simulations (DNS) of two-dimensional isothermal mixing layer and Lighthill's analogy computed in the same framework at Mach numbers between M=0.2 and M=0.4, based on the velocity difference across the layer and the ambient speed of sound. Over this range of Mach numbers, the radiated power spans several orders of magnitude. For M>=0.25, the sound power levels obtained using the three methods agree within 0.9dB, and within 0.5dB for M>=0.3. At M=0.2, where the acoustic fluctuations are weakest relative to the hydrodynamic ones, Lighthill's analogy over-predicts the radiated power by 2.8dB. In contrast, the cPCWE deviates from the DNS reference by only -1.2dB. This closer agreement is because the cPCWE source term is confined to the
vortex-pairing region, while convection and refraction are represented by its convective wave operator. Beyond reproducing the far-field sound, the cPCWE resolves the acoustic field within the shear zone itself, where the DNS' fields are masked by vortical fluctuations.
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All authors Stefan Schoder, Eman Bagheri, Hugo Vincent, Thomas Brunner
Physics and Society · Cross-listed from econ.GN
Workplace dependence in urban economies
Zsófia Zádor, Balázs Lengyel and Riccardo Di Clemente
Remote work has fundamentally reshaped urban economic life, and the spatial organisation of activity across cities. However, access to flexible work is distributed unevenly across industries, income groups, and genders, creating disparities in health risks, social mixing, and economic opportunity. Understanding where workplace dependence (WPD) is concentrated is therefore important, yet its distribution across urban areas remains poorly understood. Here we pair fine-grained hourly population data with detailed company records in a large European city to examine how location, industry composition, and socio-economic characteristics shape physical workplace attendance. By comparing workplace activity during periods of low versus high COVID-19 restrictions, we identify the determinants of WPD. We find that while industry and firm productivity are key drivers, the relationship between WPD, income, and gender is highly contingent on distance from the city center. Near the centre, female-majority and income-diverse locations show the highest WPD, consistent with a residual, place-bound service workforce. These findings reveal a spatially contingent 'service trap' at the urban core, extending remote-work inequalities beyond individuals to the urban ecosystem as a whole.
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Mathematical Physics · Cross-listed from cs.LG
Fixed and Adaptive Topological DeepONets: Functional Measurements on Hausdorff Locally Convex Spaces
Khemraj Shukla and George Em Karniadakis
Deep Operator Networks (DeepONets; arXiv:1910.03193) typically encode an input function through point values on a fixed discretization. Building on the Topological DeepONet framework of Ismailov (arXiv:2603.11972), we replace point samples by continuous linear functionals drawn from the continuous dual of a Hausdorff locally convex space $({V},\{p_\alpha\}_{\alpha\in A})$, whose
topology is generated by a point-separating family of seminorms rather than a single norm, and develop fixed and adaptive functional measurement systems. Measurements are combined with the coefficient-space Two-Step procedure of Lee and Shin (arXiv:2309.01020), while a training-only decoder and regularization stabilize the adaptive coordinates. We derive a discrete error decomposition separating measurement, output-basis, and neural-approximation errors, together with a Barron-rate refinement. The framework is evaluated on the antiderivative operator, a non-normable locally convex input space, heterogeneous Darcy flow, a controlled operator, and fixed-time and time-evolving Navier-Stokes vorticity operators. In the heterogeneous Darcy problem, the functional models retain nearly resolution-independent errors of 5.5-5.6% on unseen grids, while in the controlled problem adaptive measurements reduce the mean error below 1.2%. For the fixed-time Navier-Stokes problem, the Adaptive Topological DeepONet is the most accurate DeepONet-based model, attaining a mean relative $L^2$ error of 1.685% +/- 0.017% using 128 functional coordinates. A comparably sized
Fourier neural operator (FNO; arXiv:2010.08895) achieves the lower error 0.832% +/- 0.172%, but requires the full 64x64 input field, twice the training time, and 10.7x greater peak GPU
memory. The formulation provides compact, interpretable, and discretization-portable coordinates in the continuous dual $V'$, including for non-normable input spaces.
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Quantum Physics
Quantum Noise Mitigation with Adaptive Zero-Noise Extrapolation: A Contextual Multi-Armed Bandits Approach
Ratun Rahman and Dinh C. Nguyen
Variational
quantum circuits (VQCs) are central to near-term
quantum computing, yet their practical deployment is severely hindered by noise. While existing error mitigation methods, such as zero-noise extrapolation (ZNE), typically assume static noise, real noisy intermediate-scale
quantum (NISQ) systems exhibit dynamic, time-varying noise that remains largely unaddressed. To overcome this critical gap, our work introduces a novel adaptive noise mitigation framework for VQCs that integrates ZNE with contextual multi-armed bandits (CMAB), enabling dynamic, context-aware selection of
circuit-folding levels based on ansatz parameters (e.g., depth, parameter count) and the evolving noise environment. Unlike fixed-fold or heuristic ZNE, our approach uses online adaptation to improve the accuracy of ZNE and reduce redundant
quantum circuit executions. Our extensive simulations and experiments on real
quantum hardware reveal the following important properties: (i) deeper VQCs accumulate noise, degrading accuracy and increasing the number of
quantum circuit executions; (ii) ZNE restores
estimator fidelity when the folding level is chosen appropriately; and (iii) CMAB-guided folding cuts
quantum circuit execution round trips by up to 40%, bytes exchanged by up to 35%, and end-to-end cost by up to 30% under a 10~Mbps budget, with up to 6.9% higher
estimator fidelity (CIFAR-10, depth 3, noise band $\eta=0.05$), versus fixed-fold and grid-search ZNE. These results demonstrate substantial performance gains over existing noise mitigation methods, underscoring the effectiveness of our design in supporting robust noise mitigation for VQCs. The source code is also publicly released to support reproducibility.
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Chemical Physics
Ground-State Energy Estimation of HeH$^{+}$, ArH$^{+}$, and H$_2$O via Sample-Based Quantum Diagonalization
Jubin Park, Chae-Hyun Yoon, Minkyu Lee et al. (+1 more)
Accurate ground-state energies are essential for understanding molecular structure, chemical bonding, and reaction energetics in
quantum chemistry. In this work, we investigate the ground-state properties of the molecular systems HeH$^+$, ArH$^+$, and H$_2$O using Sample-Based
Quantum Diagonalization (SQD), a hybrid
quantum-classical framework designed for near-term
quantum devices. Unlike variational approaches such as VQE, which require deep parameterized
circuits and repeated expectation-value measurements, SQD reconstructs a low-energy determinant subspace directly from measured bitstrings. For the present calculations, bitstrings were generated on IBM
quantum hardware using shallow local
unitary cluster Jastrow (LUCJ)
circuits whose parameters were constructed from the $t_1$ and $t_2$ amplitudes of coupled-cluster singles and doubles (CCSD) calculations based on restricted Hartree–Fock (RHF) references. From these samples, we compute ground-state potential-energy curves of HeH$^+$, ArH$^+$, and H$_2$O with the 6-31G and cc-pVDZ basis sets. For all three systems, the SQD results obtained with the cc-pVDZ basis closely follow the corresponding same-basis CCSD energies and reproduce the
equilibrium-region trends of the potential-energy curves. HeH$^+$ and ArH$^+$ were chosen as simple yet astrophysically important molecular-ion
benchmarks, while H$_2$O was included as a representative polyatomic molecule to assess the applicability of SQD beyond diatomic ionic systems. At the adopted
equilibrium geometries, the deviations from the same-active-space CASCI references are 0.00, 2.51, and 6.34 mHa for HeH$^+$, ArH$^+$, and H$_2$O, respectively. These results demonstrate the feasibility of hardware-assisted SQD for the present
benchmark systems and motivate further studies of its accuracy and computational scaling for larger molecular active spaces.
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All authors Jubin Park, Chae-Hyun Yoon, Minkyu Lee, Myung-Ki Cheoun
Chemical Physics
Competing Energetics Govern Gas Permeation in Polymer of Intrinsic Microporosity (PIM) Membranes
Jianhao Qian, Ruoyu Wang and Menachem Elimelech
Polymer membranes, particularly
polymers of intrinsic microporosity (PIMs), hold great promise for gas separation applications. However, the long-dominant solution-
diffusion model, which treats the membrane as a nonporous homogeneous medium, does not resolve how gas-solid atomic interactions govern molecular transport in intrinsic micropores, limiting rational bottom-up membrane design. In this work, we employ non-
equilibrium molecular dynamics simulations to investigate the permeation of various gases (He, H2, CH4, N2, O2, and CO2) through PIM-1 as a representative PIM membrane across a range of temperatures. By analyzing the scaling of gas permeability with molecular mass, we identify a temperature-induced transition in the dominant transport mechanism. We demonstrate that this transition is governed by the competition between gas-wall interaction potential energy and thermal kinetic energy: weak interactions or elevated temperatures facilitate Knudsen-type ballistic transport, whereas strong interactions and lower temperatures favor adsorption-mediated surface
diffusion. Furthermore, molecular trajectory analysis at the membrane interface reveals two distinct entry pathways: direct entry through pore openings and surface-
diffusion-assisted entry. The surface-
diffusion-assisted pathway greatly promotes the entry of strongly interacting gases into the membrane, contributing to higher overall permeability, albeit this enhancement diminishes with increasing temperature. These findings offer a mechanistic picture of gas permeation in PIM-1 and explain the dependence of gas permeation on both gas type and temperature. More broadly, they highlight the importance of adopting a pore-flow perspective to understand gas transport in microporous
polymer membranes.
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Computational Physics
Data-driven reconstruction of dynamical systems using Takens' Theorem, manifold learning, and universal function approximators
Maximilian Topel and Andrew L. Ferguson
Embedding theorems can be used to provide theoretical guarantees about the relation between low-dimensional observations of a system and its full-dimensional state and dynamics. Such
theorems do not, however, provide guidance on observable choice,
embedding construction, or methodologies to learn the mapping between the
embedding and full-dimensional state. In this work, we develop an algorithmic framework, TAkens Reconstruction (TAR), to analyze and reconstruct arbitrary dynamical systems from low-dimensional time series using an integration of Takens' Delay
Embedding Theorem,
manifold learning techniques, and universal function approximators. We validate TAR in applications to a variety of simulated and observed dynamical systems and use it to investigate how delay vector structure impacts reconstruction accuracy. In an ecological system, we show that simple predator-prey dynamics can be reconstructed with observations taken over a wide variety of
embedding time scales. In molecular dynamics simulations of the
protein Villin, we demonstrate how including multiple time delays of the same observable series can be used to improve reconstruction of systems with multiple characteristic time scales. In the trade record of Vanguard S&P 500, we show how the approach exposes underlying dynamical phenomenologies in the data and accurate return predictions over short time horizons without access to full-dimensional
market observations. We develop and release an open-source software package to enable the application of TAR to arbitrary dynamical systems.
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Nuclear Theory
TITAN mass measurements of neutron-rich Cs, Ba and r-process lanthanide abundances
T.-H. Yeh, J.D. Cardona, Y. Wang et al. (+26 more)
We present measurements for the masses of five
neutron-rich isotopes, $^{149-151}$Cs and $^{151, 152}$Ba, probed for the first time by TITAN at TRIUMF with time-of-flight measurement techniques. We propagate these masses to the
nuclear reaction and decay data required for the simulation of the rapid
neutron capture process (r-process) nucleosynthesis in
neutron star mergers. We show that these
neutron-rich masses affect the abundance predictions near mass number $A\sim148-152$ corresponding to lanthanide element abundances at $Z=60,\,62$ and $63$. We demonstrate that these new TITAN masses smooth out the odd-even effect in isotopic abundance predictions near $A\sim150$ in both fission cycling astrophysical conditions and conditions that do not reach actinides. We further show that these new masses adjust how fission fragments settle into place when forming the final abundances, and consider the effect on comparisons with
stellar abundance ratios such as [Ag/Eu], [Sm/Eu], and [Nd/Eu].
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All authors T.-H. Yeh, J.D. Cardona, Y. Wang, J. Ash, B. Ashrafkhani, I. Belosovic, J. Bergmann, E. Dunling, L. Egoriti, G. Gelinas, G. Gwinner, Z. Hockenbery, C. Izzo, A. Jacobs, S. Kakkar, B. Kootte, E. M. Lykiardopoulou, T. Murbock, A. Mollaebrahimi, A. Ridley, S. F. Paul, W. S. Porter, M. P. Reiter, J. Ringuette, R. Simpson, C. Walls, M. R. Mumpower, N. Vassh, A.A. Kwiatkowski
High Energy Physics (Theory)
Surviving correlations across a horizon: reflected entropy for bosonic fields in non-inertial frames and black hole spacetimes
Sayid Mondal
We study the reflected
entropy and the Markov gap for modes of a free bosonic field shared by inertial observers (Alice, Charlie) and a uniformly accelerated one (Bob), for a bipartite Bell state and the tripartite Werner (W) and Greenberger–Horne–Zeilinger (GHZ) states. The bosonic Bogoliubov transformation spans an infinite-dimensional Fock space with an unbounded squeezing parameter unlike the fermionic case. By identifying a conserved charge, we block-diagonalize the reduced density
matrices into exact two-dimensional sectors, yielding closed or semi-analytic forms for all three states. Although bosonic
entanglement is known to vanish asymptotically, the Alice–Bob reflected
entropy instead saturates at a nonzero floor, retaining the surviving classical correlation, and converges to the value Alice shares with Bob's causally disconnected partner. Crucially, only the inter-wedge reflected
entropy diverges, linearly in the squeezing parameter—the sharp distinction from the fermionic case, where it stays bounded—while the Markov gaps saturate. The construction transfers verbatim to a Schwarzschild black hole, where the saturation values become mass-independent constants.
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Medical Physics · Cross-listed from eess.IV
A Foundational EDM2-Based Generative Model for High-Resolution Synthetic Fetal Ultrasound Imaging from Open Datasets
Harvey Mannering, Yilin Zhang, Ziao Liu et al. (+3 more)
Prenatal ultrasound imaging is key for assessing fetal health, but AI progress is limited by scarce,
privacy-restricted, and hard-to-annotate
datasets. We propose a high-resolution fetal ultrasound synthesis framework based on the EDM2
diffusion architecture, trained on multiple public
datasets to generate 512x512 images across six anatomical classes. Our method achieved improved image quality with lower FID scores and enhanced downstream fetal plane classification, reaching 93.36% ensemble accuracy after fine-tuning, surpassing real-data-only training. Clinical evaluation by an experienced fetal ultrasound specialist (10+ years) on 100 images yielded a mean realism score of 2.67/5, with real images rated higher than synthetic. Artefacts included smoothing, speckle irregularities, and anatomical inconsistencies. Code, data, models and other resources to reproduce this work are available at https://github.com/xfetus/fetal-ultrasound-edm2.
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All authors Harvey Mannering, Yilin Zhang, Ziao Liu, Zhiwu Huang, Jacqueline Matthew, Miguel Xochicale
Materials Science
Peter Minch, Shiya Chen, Weiyi Xia et al. (+4 more)
A wide variety of chemical substitutions in
ferromagnetic Kagome systems can lead to diverse
magnetic phases with electronic structures suitable for topological or
quantum material properties. Here, we study the electronic structure and
magnetic orderings using first-principles calculations for the
magnetic Kagome compounds ZrFe6Ge6, ZrFe6Ge4, and ZrFe6Ge5. For ZrFe6Ge6, the obtained ground-state
magnetic structure is A-type
antiferromagnetic (AFM), in agreement with existing experiments. We predicted that the
magnetic ground states of ZrFe6Ge4 and ZrFe6Ge5 are collinear A-type
bilayer AFM structures with long-period ordering that involves a mix of FM and AFM interlayer orientations. The formation of such long-range
magnetic structures appears to be a general feature and is not tied to specific substitutions. The
magnetic moments in these systems are largely local and only weakly dependent on the
magnetic configuration, with magnitudes in good agreement with available experimental estimates.
Neutron scattering experiments, which could provide direct verification of these predictions, are therefore of particular importance.
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All authors Peter Minch, Shiya Chen, Weiyi Xia, Wei-Shen Tee, Yang Sun, Cai-Zhuang Wang, Vladimir Antropov
Biological Physics
Toward a Dynamical Taxonomy of Insomnia: A Multiaxial Framework for Sleep-State Transitions and Architectural Failure
Alexander Poltorak
Insomnia disorder is defined at the syndrome level, yet similar complaints can arise from different abnormalities in sleep regulation, state transition, state stabilization, spatial recruitment, architectural sequencing, and state perception. We propose a multiaxial dynamical framework whose principal contribution is organizational: a candidate profile is specified by the dynamical operation that fails, the sleep stage or boundary at which it fails, and its causal status. Objective sleep duration, age, circadian phase, comorbidity, medication exposure, and night-to-night variability are modifier/
covariate dimensions rather than additional mechanistic classes. A local Landau-Ginzburg formalism, adopted from prior cortical and sleep-dynamics work, supplies a phenomenological
language for nested hypotheses. Its relaxational form applies only to boundary-local dynamics under an approximate gradient description; non-gradient escape requires an action or quasipotential treatment, and whole-night REM-NREM sequencing requires reactive or oscillatory dynamics. Routine polysomnography usually identifies effective combinations rather than
curvature, escape action, bias, noise, and relaxation separately. The strongest boundary-level evidence concerns sleep onset, where published results are consistent with bifurcation-like or bistable dynamics but do not yet exclude a driven smooth transition produced by the homeostatic-circadian ramp. The remaining operation classes are hypothesis-generating extensions. The taxonomy is judged by pragmatic utility, including improved communication, stratification, and prediction; the scalar-field implementation and specific dynamical profiles are separately falsifiable. The framework is a phenomenological organizing model rather than a new diagnosis, validated biomarker, or treatment-selection system.
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Earth and Planetary Astrophysics
The forced orbital planes of the Plutinos and other resonant KBOs
Ian Matheson and Renu Malhotra
The forced plane of non-resonant minor
planets has been understood to be well-estimated by the local Laplace plane given by linear Laplace-Lagrange secular perturbation theory, but there is no extant theory for the forced plane of resonant minor
planets. With improved methodology, we revisit our previous measurement of the mean orbital plane of the observed Plutinos, a group of Kuiper belt objects locked in Neptune's 3:2 mean motion resonance. In the J2000 ecliptic-equinox reference frame, the measured mean plane has an inclination of 1.9 degrees and an ascending node at 46.8 degrees longitude, with a 95% confidence of 2 degrees in the plane position; it is well separated from the local Laplace plane but is indistinguishable from the
solar system's invariable plane. We also show that, at high statistical confidence, the two dynamical subgroups, the doubly resonant Plutinos whose arguments of perihelion librate about +90 and -90 degrees, have different mean planes from each other. Additionally, we measure the mean planes of four other observed resonant groups in the Kuiper belt: the 5:3, 7:4, 2:1, and 5:2. Although these groups have substantial sample sizes (in the range 56-105), their mean planes are presently not statistically distinguishable from their local Laplace plane, Neptune's plane, and the invariable plane. For all five resonant groups, we also report the best-fit von Mises function for their inclinations. These empirical measurements underscore the need for theoretical analysis to understand the spatial dynamics of resonant populations of minor
planets. Such analysis could potentially enable their use for uncovering unmodeled perturbations and/or undiscovered perturbers.
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High Energy Astrophysical Phenomena
Reconstructing Core-Collapse Supernova Gravitational-Wave Signals with Transdimensional Bayesian Inference
Hayden Chapman, Jade Powell, Nir Guttman et al. (+2 more)
Core-collapse
supernovae (CCSNe) are promising future sources of gravitational waves for current and next-generation observatories. Reconstructing CCSN gravitational-wave signals is challenging as they contain
stochastic elements, have multiple complex features, and cover a wide frequency band. The stochasticity of the signal in particular motivates the need for morphology-independent reconstruction techniques which, once observed, will enable us to infer properties of the newly born proto-
neutron star, the rotation, and the unknown CCSN explosion mechanism. In this work, we investigate the reconstruction of gravitational-wave signals from CCSNe using the transdimensional
Bayesian inference framework tBilby. We demonstrate the method using simulated signals in synthetic Advanced LIGO detector noise at a range of signal-to-noise ratios. We reconstruct the signals using two types of wavelets: sine Gaussians and chirplets. We calculate overlaps between injected and reconstructed signals of up to 85%. We find that even when reconstruction overlap values are low, enough of the time-frequency structure of the dominant mode is captured to still make statements about the size of the evolving proto-
neutron star. These capabilities establish tBilby as a powerful tool for gravitational-wave astronomy with burst sources.
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All authors Hayden Chapman, Jade Powell, Nir Guttman, Yi Shuen Christine Lee, Paul D. Lasky
Astrophysics of Galaxies
The Zero-Age Massive Stellar Population of W49A from VLA Observations
M. Juárez-Gama, R. Galván-Madrid, G. Suárez et al. (+14 more)
We use all-configuration VLA data at 3.3 cm with a physical resolution of ~2000 AU to infer the embedded zero-age massive
stellar population of the W49A protocluster, as traced by its compact, ultracompact (UC), and hypercompact (HC) H II regions. Our method consists of visual source identification, the derivation of
stellar ionizing-
photon rates from the observed emission measure, and the further derivation of
stellar masses and luminosities using state-of-the-art
stellar calibrations. Considering the 101 robust detections, maximum-likelihood estimation fitting of the high-mass end (M > 10.9 M_\odot) of the sample yields power-law slopes Gamma >= 2.40 for the logarithmic representation of the
stellar initial mass function (IMF): dN/d(log M) proportional to M^{-Gamma}. The result is robust considering different assumptions for the ionizing
stellar systems. The slopes remain at Gamma >= 1.88 after correction for optical depth effects at 3.3 cm. Therefore, the inferred distribution of
stellar masses presents a clear deficit in the high-mass end as compared to the standard
stellar IMF (Gamma = 1.35). We propose that this is due to a shorter lifetime of the
radio-detected H II regions produced by higher-mass
stars, but evolutionary effects in the mass distribution of
star formation within embedded protoclusters cannot be discarded.
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All authors M. Juárez-Gama, R. Galván-Madrid, G. Suárez, C. G. De Pree, J. J. Tobin, G. Bruzual, A. Ginsburg, J. E. Mendoza-Torres, H. B. Liu, D. Wilner, T. Nony, A. Parra-López, R. Rivera-Soto, A. F. McLeod, N. Cunningham, X. Lu, E. F. Jiménez-Andrade
Materials Science
Low-resistivity nitrogen-doped p-type Cu2O thin films enabled by millisecond flash lamp annealing
Jan Koloros, Pavel Baroch, Thomas Preußner et al. (+3 more)
Flash lamp annealing (FLA) provides millisecond-scale thermal processing, but its effects on p-type Cu2O and nitrogen-related defects remain poorly understood. Reactively sputtered Cu2O:N films with different nitrogen content were deposited using reactive high-power impulse magnetron sputtering and exposed to a single 1.9 ms FLA pulse at 4.9 - 11.7 J cm-2. Their compositional,morphological, structural, vibrational, electrical, and optical responses were evaluated. WDS showed no statistically significant change in total elemental composition, and XRD confirmed retention of cubic Cu2O. Nitrogen-containing films exhibited surface coarsening, shifts of the Cu2O reflections, and non-monotonic changes in the Raman band assigned to molecular N2. Nitrogen incorporation substantially reduced the as-deposited resistivity. The very low value of 0.045 {\Omega}cm was obtained after FLA at 4.9 J cm-2, whereas higher energy densities markedly increased resistivity.
Hall measurements showed increasing mobility but decreasing hole concentration. At high energy densities, the optical band gap of nitrogen-rich films widened. The results define a narrow low-energy processing window with a positive effect on electrical properties, whereas high-energy FLA modifies the structure and optical absorption edge but degrades electrical conductivity.
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All authors Jan Koloros, Pavel Baroch, Thomas Preußner, Matthias Fahland, Michaela Červená, Jiří Rezek
Earth and Planetary Astrophysics
SMA 200-400 GHz Survey for 10 faint Class II Disks in the Taurus Molecular Cloud
Chia-Ying Chung, Hauyu Baobab Liu, Sean M. Andrews et al. (+3 more)
We have performed Submillimeter Array (SMA) observations of 198.0-407.5 GHz broadband spectra of 10 Class II protoplanetary disks in the Taurus-Auriga region. The 337 GHz flux densities ($F_{\rm 337 GHz}$) of these objects are in the range of 8.2-34 mJy. The median and standard deviation of the 198-358 GHz spectral indices ($\alpha_{198-358}$) of these 10 Class II disks are 1.9 and 0.3, respectively. Compared to the recent, similar SMA survey on another 47 Class II disks that are brighter at (sub)millimeter bands ($F_{\rm 337 GHz}\sim$20-730 mJy), there is no evidence that these newly observed 10 fainter Class II disks have systematically different $\alpha_{198-358}$ values. At $>$230 GHz frequencies, the optical depths of these 10 fainter Class II disks may be as high as those of the brighter sources, which may be $\gtrsim$5. In addition, the low ($<$2.0) values of $\alpha_{198-358}$ in some faint objects may be explained by the effect of
dust self-scattering, with maximum
dust grain size ($a_{\rm max}$) $\sim$ 100 $\mu$m, or by contamination by free-free emission.
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All authors Chia-Ying Chung, Hauyu Baobab Liu, Sean M. Andrews, Mark A. Gurwell, Melvyn Wright, Feng Long
General Physics
Moving Magnetic Flux and Electromagnetic Induction
Allan Walstad
Magnetic flux can move, and moving
magnetic flux is associated with induced electric fields. Where there are multiple sources of flux, the induced electric field is the vector resultant of the induced fields attributable to the fluxes acting individually; it is not necessarily associated with the resultant
magnetic field. The key insight is that flux can move through regions in which the
magnetic field itself vanishes, much as electric charge can move (as electric current) through a region in which the net charge density is zero. For this reason, moving flux can account for the induced emf around a long solenoid in which the current is changing. It also accounts for unipolar induction, and this account is testable.
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Quantum Physics
Experimental demonstration of the Quantum Fourier Transform on up to 100 qubits using a convolutional compilation strategy
Paul Coote, Michael J. Biercuk and Yuval Baum
We present and experimentally validate the `Convolutional QFT': a constructive compilation strategy for the
Quantum Fourier Transform (QFT) subroutine on a linear nearest neighbor (LNN)
qubit topology. We first introduce a novel strategy that compiles the $n$-
qubit QFT onto an LNN
topology using only $n^2 - n$ $CX$ gates, matching requirements of a direct compilation on an all-to-all architecture. We then derive the convolutional variant used in our experiments, which requires an additional two $CX$ gates in total, and is realized via a compact, translation-invariant kernel
circuit gadget that traverses a
quantum register. We demonstrate the power of the convolutional compilation strategy on the IBM
Quantum Platform by executing QFT benchmarking
circuits. We measure a process fidelity of 11.4% at 50
qubits, and 1.8% at 80
qubits. The correct output state remains clearly distinguishable above background noise up to 100
qubits. These results constitute the largest experimental QFT demonstrated on any
quantum computing hardware to date.
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Quantum Physics · Cross-listed from cs.IT
Diversity in Coded TE-QKD Channels: Achieving Infinite Diversity out of Finite System Resources
Shaikha S. Al-Qahtani, Siyao Li and Joseph J. Boutros
We establish conditions and give proofs on how an error-correcting code can attain infinite diversity in a time-
entanglement quantum key distribution (TE-QKD) reconciliation. The shocking result, never encountered in the literature on coding and communication theory, is that a decoder exhibits an infinite diversity order while the channel has finite diversity and the code has a relatively short finite length. This paper studies the diversity order of coded TE-QKD reconciliation, defined by the asymptotic slope of the error probability at high signal-to-noise ratio. For bounded-distance algebraic decoding, we derive a necessary and sufficient condition in terms of the number of
photons per codeword and the decoding radius. For soft-decision decoding, we introduce the maximal finite diversity (MFD) property and prove that infinite diversity is achieved if and only if the code is MFD deficient. The infinite diversity in TE-QKD has no counterpart in classical fading channels, where decoding can only multiply a finite diversity order by a finite factor. Examples of short codes based on Golay, Reed-Solomon, Bose-Chaudhuri-Hocquenghem (BCH), and Reed-Muller codes validate the analysis and illustrate how the TE-QKD system parameters and the relatively short code parameters affect the achievable diversity for both hard and soft information reconciliation.
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Quantum Physics · Cross-listed from cs.CY
School network reorganization under educational and spatial constraints using classical and quantum optimization
Alessia Ciacco, Luigi Di Puglia Pugliese and Francesca Guerriero
School network reorganization is a strategic planning problem that requires balancing demographic trends, territorial accessibility, educational requirements, and institutional constraints while ensuring an efficient allocation of public resources. This paper proposes an optimization framework for school dimensioning decisions based on a novel Integer Linear Programming formulation integrating geographical, administrative, and educational criteria. A synthetic
benchmark generator is introduced to evaluate the scalability and computational performance of the model on artificial instances, while a real-world case study involving the complete public school network of the Calabria region (Italy) is conducted using actual institutional, territorial, and demographic data. Furthermore, the model is implemented within a hybrid
quantum optimization environment. The results show that the proposed formulation can be effectively solved by exact classical optimization and can also be represented and evaluated within a hybrid
quantum-classical optimization framework. The computational experiments provide a proof-of-concept assessment of the applicability of hybrid
quantum optimization to the considered school aggregation problem, while also highlighting the current computational advantage of classical optimization and the limitations of the tested
benchmark instances.
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Quantum Physics
Qutrit entanglement and joint multi-parameter estimation in an optical clock platform
Ohad Lib, Shuheng Liu, Maximilian Ammenwerth et al. (+7 more)
Quantum metrology harnesses
entanglement to improve measurement precision beyond classical limits. While standard protocols rely on two-level
qubits to estimate a single parameter, extending them to entangled multi-level qudits enables the optimal simultaneous estimation of multiple parameters within a single probe. However, generating such multi-level
entanglement and harnessing it for joint multi-parameter estimation in atomic clocks has remained an outstanding challenge. Here, we experimentally demonstrate genuine qutrit
entanglement and joint multi-parameter estimation in an optical clock platform. Leveraging control over the ground state and two fine-structure clock states of $^{88}\text{Sr}$ atoms trapped in triple-magic optical tweezers, we generate a maximally entangled two-qutrit state with a loss-postselected fidelity of F = 0.85(1), certifying genuine multi-level
entanglement. Taking advantage of this high-dimensional
entanglement, we theoretically construct and experimentally realize an optimal two-qutrit metrological probe state and noise-robust readout
circuit to simultaneously estimate injected phases on two optical clock transitions. We observe a joint estimation variance below the ideal individual two-level sensing threshold, and show theoretically that this advantage persists at state-of-the-art atom numbers under
circuit-level noise. These results demonstrate the key building blocks towards
quantum information science with high-dimensional states encoded in the internal energy levels of neutral atoms.
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All authors Ohad Lib, Shuheng Liu, Maximilian Ammenwerth, Hendrik Timme, Shijia Sun, Qiongyi He, Marcus Huber, Giuseppe Vitagliano, Immanuel Bloch, Johannes Zeiher
Solar and Stellar Astrophysics
The IACOB project XVIII. Prevalence of short-period binaries among Galactic helium rich O-type stars
C. Martínez-Sebastián, R. Gamen, O. G. Benvenuto et al. (+6 more)
For decades, the origin of helium enrichment in O-type
stars has remained an open question. In this study, we investigate the correlation between surface helium abundance and orbital parameters for a sample of 45 O-type SB1 systems –including Cyg X-1. We find seven He-rich systems, all of which are concentrated at short orbital periods (P$\lesssim 15$ days) and are classified as runaways. In addition, four of them present relatively high eccentricities, while the other three have ellipsoidal variations. We argue that these properties are the result of binary interaction. These findings provide strong observational evidence that binary interaction is the dominant origin of helium enrichment in O-type
stars. This result has important implications for the treatment of chemical mixing and surface abundances in massive-
star evolutionary models, and establishes helium enrichment as a promising observational tracer for identifying post-interaction binary systems.
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All authors C. Martínez-Sebastián, R. Gamen, O. G. Benvenuto, E. A. Saavedra, M. Carretero-Castrillo, M. Contreras, G. Holgado, J. Maíz Apellániz, S. Simón-Díaz
High Energy Physics (Theory)
Exact Lattice Identities and Continuum-Limit Dyson–Schwinger Equations for Yang-Mills Theory
Arpan Chatterjee, Marco Frasca, Anish Ghoshal et al. (+1 more)
Starting from SU(N) on the
lattice, we give a rigorous derivation of the Dyson–Schwinger equations in the continuum limit. We formulate the Dyson–Schwinger identities for the
lattice Yang–Mills theory directly in terms of the link variables $U_\mu(m)\in SU(N)$, exploiting the invariance of the Haar measure under left group translations. This provides an exact
lattice derivation of the corresponding master equation for the Wilson action, expressed through left-invariant Lie derivatives acting on individual links. Because the construction is carried out directly on the compact gauge group, it avoids the ambiguities associated with introducing Lie-
algebra valued gauge potentials as primary integration variables at finite
lattice spacing. For practical applications, in a second part we then break down the gauge degree of freedom by choosing Feynman gauge. We analyze the continuum-limit form of the resulting
lattice identities and derive equations for the one- and two-point connected functions. Under a further simplifying reduction, these equations close to a tractable scalar system. Our results establish a direct bridge between exact
lattice identities and the functional equations commonly used in continuum nonperturbative studies of Yang–Mills theory.
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All authors Arpan Chatterjee, Marco Frasca, Anish Ghoshal, Stefan Groote