Instrumentation and Detectors
A Silicon Photonic Transmitter for High Energy Physics and Cryogenic Detectors
Adam Quinn and Sajjad Moazeni
We demonstrate a silicon photonic transmitter designed for reading out physics detectors in extreme environments. The transmitter operates at room and cryogenic temperature and consists of a micro-ring modulator and a co-designed CMOS serializer and driver.
General Relativity and Quantum Cosmology
Bayesian constraints on quadratic $f(Q)$ gravity from the ADM mass of white dwarfs
Edson Otoniel, Lucas A. Souza, Jonathan A. Rebouças et al. (+1 more)
We calculate static
equilibrium sequences for white
dwarfs (WDs) in quadratic symmetric teleparallel
gravity, f(Q)=Q+alpha Q^2, and perform a
Bayesian comparison between the negative-coupling sector, general relativity (GR), and the positive-coupling sector using mass-radius measurements. Regular interior solutions are obtained by imposing the affine field equation and selecting the analytic branch C=r exp(B/2), and are matched to asymptotically flat exterior spacetimes to determine the ADM mass. The matter sector is described by a cold carbon-12 equation of state including relativistic electron degeneracy,
nuclear rest energy, and Coulomb
lattice corrections. Central density is marginalized at fixed alpha with a log-uniform prior. The sequences span 10^14 <= |alpha|/cm^2 <= 10^21. Positive couplings shift the compact branch toward larger radii and lower masses, whereas negative couplings produce high-mass extensions, including an admissible
equilibrium configuration with M_ADM=14.34
solar masses. Using Sirius B, QS Vir, V471 Tau B, ZTF J1901+1458, and LHS 4033, we obtain conditional posterior medians alpha_-= -1.12x10^16 cm^2 and alpha_+=1.85x10^17 cm^2. With equal prior weights, the posterior probabilities for the negative, GR, and positive sectors are 0.228, 0.378, and 0.395, respectively, with ln(B_+/GR)=0.043. Current data therefore provide conditional constraints on the coupling but no direct evidence for modified
gravity, emphasizing that the ADM mass prescription and admissible
stellar domain must be consistently defined when using WD observations to constrain the theory.
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All authors Edson Otoniel, Lucas A. Souza, Jonathan A. Rebouças, Juan M. Z. Pretel
Fluid Dynamics
A Sharp and Conservative VOF Method for Multicomponent Liquid–Gas Mass Transfer: Bubble Dissolution and Droplet Evaporation
Shuo Zhao, Jie Zhang and Ming-Jiu Ni
We present a sharp and conservative geometrical VOF–finite-volume method for multicomponent
liquid–gas mass transfer across deformable interfaces. The method solves problems in which multiple species are coupled through interfacial mass balances, latent-heat exchange, and vapor–
liquid equilibrium. The key novelty is a fully sharp two-field treatment of scalar transport: the species and temperature equations are solved separately in the
liquid and gas phases, while the one-sided Robin conditions for species and the two-sided flux jump for temperature are imposed directly on the reconstructed interface through an embedded-boundary discretization. This avoids both volumetric regularization of interfacial source terms and explicit coupling based on previous-time-step interfacial data. A consistent geometrical advection scheme is used for volume, momentum, energy, and species transport, and a sequential coupling strategy is developed to determine the partial interfacial mass fluxes, close the temperature equation, and update the thermodynamic-
equilibrium state. The method is validated through single- and multicomponent bubble dissolution, single-component droplet evaporation, non-ideal ethanol–isooctane droplet evaporation, and sessile water–glycerol droplet evaporation. The results demonstrate second-order accuracy, accurate interfacial flux prediction, good mass and energy conservation, and the ability to capture complex multicomponent effects such as gas replacement, azeotropic
volatility reversal, and composition-driven Marangoni flow.
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Fluid Dynamics
Liquid bridges between horizontal cylinders: effects of gravity and electric fields
Agnes J. Bokányi-Tóth, Andrew J. Archer, Radu Cimpeanu et al. (+3 more)
Liquid bridges suspended between two parallel horizontal cylinders are studied using experiments, reduced-order mathematical modelling and numerical simulations. Both non-electrified and electrified configurations are considered, with the cylinders acting as electrodes between which a potential difference can be applied. The initial focus is on
equilibrium bridge shapes, while the dynamics is examined only in the non-electrified case. In the experiments,
transformer-oil bridges are investigated and modelled as perfect dielectrics. The electric field counteracts the gravitational effects and causes the bridges to rise and become flatter, with shapes that are well described by Young–Laplace-type equations containing non-local electric-field contributions evaluated using a boundary-element method. Bifurcation diagrams of these solutions are constructed by pseudo-arclength continuation to characterise the dependence of bridge shapes on
liquid volume and electric-field strength. In the absence of an electric field, the transient relaxation to
equilibrium is analysed using a reduced-order model developed using Onsager's variational principle, with comparison to direct numerical simulations. The steady states predicted by the reduced-order model agree closely with those of the full formulation over a wide parameter range, and the dynamics is well captured in the overdamped regime.
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All authors Agnes J. Bokányi-Tóth, Andrew J. Archer, Radu Cimpeanu, H. C. Hemaka Bandulasena, Gyula I. Tóth, Dmitri Tseluiko
Mathematical Physics · Cross-listed from math.DG
The Cheeger constant of curved tubes in real space forms
Petr Vlachopulos
Motivated by the
geometric properties of curved tubes $T\left(P,a\right)$ defined by closed curves $P$, we compute the Cheeger constant $h\left(T\left(P,a\right)\right)$ in the real space forms of arbitrary dimensions with constant sectional
curvature. The structure and properties of the system of
Fermi coordinates allows us to parametrize the curved tube and straightforwardly compute the upper bound of $h\left(T\left(P,a\right)\right)$ using the exact formulas for the area and volume of $T\left(P,a\right)$. Next, we derive the lower bound by combining the geometry of tubes with a calibration-type argument. The key idea is to describe the tube using geodesic spheres moving along the underlying curve $P$, which provides a natural outward direction and makes the estimate geometrically transparent. This allows us to compute the lower bound via the divergence
theorem. Finally, for the class of unbounded curved tubes in noncompact real space forms, we also compute the Cheeger constant and prove that there is no finite-volume Cheeger set.
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Physics and Society
Grant-Making Under Uncertainty
Daniel L. Goroff
The theory of Decision-making under uncertainty as it applies to NIH grant-making generally and to NIH research plans concerning the science of science in particular.
Earth and Planetary Astrophysics
Astro-Hunters: Machine Learning for Exoplanet Transit Detection in TESS Photometry
Fatimah Emad Eldin
Finding
planets beyond the
Solar System is now largely a data-analysis problem: photometric surveys return far more
stellar light curves than can be inspected by eye, and machine learning is increasingly asked to recognise the faint, periodic dimming of a transiting
planet. Whether such a detector works turns on a choice that is seldom reported: how its training labels were made. No catalogue disposes the individual measurements a per-cadence detector must classify, so the annotation has to be derived, and this paper asks what that costs. We present Astro-Hunters, an end-to-end pipeline over TESS two-minute photometry:
retrieval, detrending, seven sliding-window statistics per cadence, and gradient-boosted classification. These components are deliberately conventional. What is new is the treatment of label provenance as an experimental variable, a corpus of 189,279 cadences from twelve confirmed hosts annotated from published ephemerides rather than from the photometry, and a physical bound on what the task permits. Six classifier families are compared under a
star-disjoint protocol. Holding features, model and protocol fixed, precision–recall performance spans a factor of 29 across label sources against 1.8 across architectures. Labels from an isolation forest fitted to the classifier's own features give an apparent AUC of 0.9915 that measures circularity; an unconverted transit epoch drives performance to chance; correct annotation gives AUC 0.788 at 5.3 times the prevalence baseline. The ceiling is observational, not architectural: a median single-cadence signal-to-noise ratio of 2.10 caps per-cadence AUC at 0.932. A Box Least Squares baseline recovers eight of twelve orbital periods from one sector. Phase-folding, not classifier capacity, is what makes the transit signal accessible.
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Statistical Mechanics
Embedding Paired Free-Fermion Gaussian States into Gutzwiller-Projected Bardeen–Cooper–Schrieffer Wave Functions
Ryui Kaneko
Gutzwiller-projected Bardeen–Cooper–Schrieffer (BCS) wave functions of Abrikosov
fermions are widely used to describe
quantum many-body states. Taking the one-dimensional transverse-field Ising model as an example, we exactly embed any even-parity spinless fermionic Gaussian state representable as a paired exponential in the chosen particle basis into a projected BCS state of spinful Abrikosov
fermions. The construction provides controlled initial states for variational Monte Carlo studies of nonintegrable models.
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General Relativity and Quantum Cosmology
Removability criterion for radiative corrections to the Starobinsky attractor in weakly nonlocal gravity
Ekapob Kulchoakrungsun, Phongpichit Channuie and Daris Samart
Radiative corrections at the percent level can shift the predictions of $\alpha$-attractor and Starobinsky-like models into the region of the $(n_s,r)$ plane preferred by ACT DR6. We show that the decisive property is not the size of a correction but whether it is removable. In the slow-roll $N$-formalism the observables are functionals of $\eps(N)$, and equality of $\eps(N)$ on an interval reconstructs the potential up to an amplitude rescaling and a shift of the canonical field. A larger class, selected by $(V/V')\Delta'={\rm const}$, preserves the leading predictions and provides a criterion for any proposed deformation. In weakly nonlocal completions of $R+R^{2}$ the improvement scale $\mu=H(\phi)$ makes the renormalization-group time one half of the logarithm of the tree potential, so the local one-loop flow passes the test and evolves the model onto the E-model family $V\propto(1-e^{-\sqrt{2/3}\,\phi/\mpl})^{p}$ with $p=2+K$. Since the divergent local beta functions of these super-renormalizable completions are one-loop exact, no higher-loop local running modifies this picture. The induced shifts are $\ord(\ln N/N^{2})$ in $n_s$, obtained in closed form for the removable part and numerically for the rest. The number of $e$-folds, which the criterion does not protect, contributes at the \red{$22\%$} level with an opposite sign. Matter-induced corrections fail the same test at leading order, which is why they shift the predictions. Among the deformations proposed since ACT DR6, an $R^{n}$ term in $f(R)$ gives $(V/V')\Delta'=\ord(N^{n-1})$, so only $n=2$ is removable, and no deformation that increases $n_s$ satisfies the criterion. For Standard Model matter, the removable channel is fixed by the
Higgs nonminimal coupling alone and is $\ord(10^{-11})$, because the measured amplitude sets the coefficient of $R^{2}$ to $5.1\times10^{8}$.
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Cosmology and Nongalactic Astrophysics
Investigating The Effects of Early Dark Energy on Large-scale Structure Within the EDENS Suite
Sophie Hodgson, Patrick Wells, Katrin Heitmann et al. (+1 more)
Early Dark Energy (EDE) models have been suggested as a possible solution to the so-called Hubble Tension, a discrepancy of the measurement of the Hubble constant at early and late times. In this paper, we investigate the effects of EDE on large-scale structure probes of cosmology via the EDENS (Early Dark Energy N-body Simulations) suite. The EDENS suite extends the reach of available EDE simulations considerably by adding volume and resolution. We derive several key metrics, such as the
halo mass function, the nonlinear power spectrum, and the concentration-mass relation. Furthermore, we implement a
halo occupation distribution model to populate the simulations with synthetic
galaxies. This allows us to measure the
galaxy-
galaxy correlation function and
galaxy bias. We choose an EDE model that is consistent with observations across several probes and allows for the increase of the present day value of the Hubble constant to resolve the Hubble tension. This model adds three more parameters to the standard $\Lambda$CDM model. Additionally, it requires small shifts in the best-fit $\Lambda$CDM cosmological parameters to accommodate existing observational constraints. We find significant differences between the standard $\Lambda$CDM model and the EDE model, suggesting that some of our chosen metrics may allow us to distinguish EDE from $\Lambda$CDM, and future observations should help further constrain possible cosmological models. We release outputs from our simulations via the OpenCosmo data portal.
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All authors Sophie Hodgson, Patrick Wells, Katrin Heitmann, Niyantri Krishnan
High Energy Physics (Theory)
Variable-mass sine-Gordon with point defects: integrability, soliton transmission, and quasi-conservation
A.R. Aguirre, H. Blas, H.F. Callisaya et al. (+1 more)
We study integrable variable-mass sine-Gordon model (vmSG) with point defects. Using the Lax and Bäcklund-gauge formulations, we construct type-I and type-II defect
matrices, derive the corresponding sewing conditions, and generate the bulk and defect contributions to an infinite hierarchy of conserved charges. The lowest members reduce to the standard sine-Gordon energy and momentum in the homogeneous limit, while for inhomogeneous backgrounds they define integrability-generated energy- and momentum-type quantities. Defect compatibility imposes matching conditions on the variable-mass functions across the defect. An analytical transmission factor $z$ characterizes
soliton transmission, topological conversion, and absorption/emission processes. We then deform the type-I sewing conditions by parameters $\alpha$ and $\beta$ and derive the associated defect anomalies. Consistent one-
soliton transmission is recovered for $\alpha \beta =1$, whereas for $\alpha \beta \neq 1$ parity-centered kink-kink and kink-antikink transmissions display vanishing lowest order integrated anomalies but no generic vanishing at higher order. Numerical simulations reproduce the integrable transmission/conversion regimes and show that non-integrable defects generate small residual disturbances and lowest order quasi-conserved charges, while quasi-conservation of the higher order charges remains unestablished. These results elucidate how exact defect integrability deforms into charge-dependent quasi-conservation and establish a framework for defect-controlled
soliton transport in inhomogeneous media, with potential applications to nonuniform Josephson junctions,
magnetic and nonlinear-optical systems, and effective molecular and DNA models.
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All authors A.R. Aguirre, H. Blas, H.F. Callisaya, M.C. de Oliveira
Cosmology and Nongalactic Astrophysics
Dark Energy in the $w-c_s^2$ Plane
Oem Trivedi, Robert J. Scherrer and Alfredo Gurrola
We introduce a unified framework for dark energy diagnostics based on the joint phase space of the equation of state $w$ and the sound speed $c_s^2$. The resulting $w-c_s^2$ plane provides a minimal extension beyond background cosmology, capturing both the expansion history and perturbative properties within a single representation. Building on this framework, we define the microphysical flow parameter $F=dc_s^2/dw$, which encodes the dynamical relation between background
evolution and perturbative response. We derive a direct connection between the present-day value $F_0$, $H_0$, and $\sigma_8$, and show that the microphysical flow parameter enables a hierarchy of increasingly stringent consistency tests that substantially reduce the viable dark energy theory space. We further demonstrate how trajectories in the $w-c_s^2$ plane distinguish models that are nearly degenerate at the level of $w(a)$, including canonical quintessence, Chaplygin gas models, and noncanonical scalar field realizations. This framework provides a compact phenomenological bridge between dark energy microphysics and future perturbation-sensitive observations, establishing $F_0$ as a useful discriminator of the kinetic structure underlying
cosmic acceleration.
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Earth and Planetary Astrophysics
Atmospheric Reconnaissance of TRAPPIST-1 f with JWST NIRISS SOSS: No Evidence for the Transit Light Source Effect
Olivia Lim, René Doyon, Ryan J. MacDonald et al. (+25 more)
In just over three years of operation, JWST has observed all seven
planets of the TRAPPIST-1 system. The two innermost
planets were found to have little to no atmosphere, barring the presence of high-altitude aerosols. Here we present the first JWST transit spectra of the habitable-zone
exoplanet TRAPPIST-1 f, which were obtained with NIRISS SOSS over the course of five transits. At least one
stellar flare occurred in each visit, but unlike observations of closer-in TRAPPIST-1
planets, no evidence for contamination of the transit spectra from unocculted
stellar surface heterogeneities was found. This non-detection does not guarantee the absence of unocculted heterogeneities in all future transit observations of this
planet, and it could be explained by the transit chord of TRAPPIST-1 f having properties similar to the average, out-of-transit, visible
stellar hemisphere at the time of observation. The transit spectra exhibit slopes ranging from -365 ppm/um down to 15 ppm/um, which we attribute to
stellar variability, that is,
flares and/or smaller-scale events. The visits least affected by
flares rule out H2/He-dominated atmospheres with surface pressures higher than about 20 mbar at 95% confidence. For high-mean-molecular-mass atmospheres, the exact upper limits on surface pressures depend on the reduction pipeline and on the treatment of the residual slopes in the transit spectra.
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All authors Olivia Lim, René Doyon, Ryan J. MacDonald, Étienne Artigau, Michael Radica, Mykhaylo Plotnykov, Alexandrine L'Heureux, Caroline Piaulet-Ghorayeb, Louis-Philippe Coulombe, David Lafrenière, Thomas J. Fauchez, Martin Turbet, Diana Valencia, Loïc Albert, Laura Flagg, Björn Benneke, Neil J. Cook, Pierre-Alexis Roy, Lisa Kaltenegger, Charles Cadieux, Nicolas B. Cowan, Michaël Gillon, Romain Allart, Lisa Dang, Doug Johnstone, Stefan Pelletier, Jared Splinter, Jake Taylor
Instrumentation and Methods for Astrophysics
On-sky demonstration of dual-field interferometry at the CHARA Array
Narsireddy Anugu, John D. Monnier, Douglas R. Gies et al. (+10 more)
Dual-field interferometry uses a bright reference
star for real-time fringe tracking, allowing a second beam combiner to record long coherent integrations on a fainter off-axis science target. At the Center for High Angular Resolution Astronomy (CHARA) Array, we implement this mode using the six-
telescope MIRC-X and MYSTIC beam combiners in the H and K bands, respectively. We first demonstrated this capability in summer 2025 on the hierarchical triple $\alpha$~Piscium. MIRC-X tracked component A in the $H$ band, while MYSTIC observed component B in the K band, resolving the 7~mas Ba–Bb subsystem and measuring the relative astrometry of the 1.85~arcsec A–B pair with an uncertainty of 234~$\mu$as. Here, we describe subsequent phase-tracking testing, preliminary sensitivity simulations, and planned instrumental upgrades aimed at extending this mode to faint off-axis science targets.
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All authors Narsireddy Anugu, John D. Monnier, Douglas R. Gies, Jeremy Jones, Robert Klement, Stefan Kraus, Rainer Köhler, Karolina Kubiak, Cyprien Lanthermann, Edgar R. Ligon, Denis Mourard, Gail H. Schaefer, Nicholas J. Scott
Quantum Physics
One-at-a-Time Quantum Guessing: Multipartite Entanglement Beyond MoE Games
Michael Schleppy and Emina Soljanin
Multipartite
entanglement remains a challenging and not fully understood aspect of
quantum information. Monogamy-of-
Entanglement (MoE) games have been highly effective for studying limitations on the usefulness of
entanglement imposed by monogamy constraints. To better reveal the extent to which multipartite
entanglement can be useful, we introduce a class of
quantum guessing games, termed One-at-a-Time Guessing (OTG) games. In these games,
quantum players individually guess the outcomes of random measurements performed by a referee on a pre-shared entangled state. Unlike MoE games, OTG games select players individually at random according to a specified probability distribution, thereby probing each player's correlation with the referee. We show that, despite monogamy constraints, players sharing certain entangled states can moderately outperform those relying only on classical uncertainty. This advantage arises even in simple OTG games involving only Pauli measurements on
qubits, where optimal
entanglement increases the winning probability by at least 4%. This contrasts with MoE games, where shared
entanglement has been shown in several settings to provide only limited (if any) advantage over classical strategies. We further establish a majorization property: the value of an OTG game respects the majorization ordering of the player-selection probability distribution. We also analyze in detail a two-player OTG game in which the referee measures one of the three Pauli observables on a
qubit, and show that it is optimally played using a specific parameterized family of three-
qubit $W$-like states. These results suggest that OTG games provide a useful framework for investigating the usefulness of multipartite
entanglement in multiparty
quantum correlations.
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Materials Science
Discovery of novel magnetic Y-Mn-B compounds via advanced machine learning guided framework
Weiyi Xia, Wei Shen Tee, Maxim Moraru et al. (+2 more)
Rare-earth transition-metal borides offer critical structural motifs for permanent-magnet design; however, the manganese-rich regions within these compositional phase spaces remain largely unexplored. In this work, we develop an advanced machine-learning-assisted discovery framework to explore Y-Mn-B ternary system. Starting from over one million hypothetical structures generated from known structures in databases, we filtered promising candidates by first applying graph neural networks to predict material stability, then using machine-learning-interatomic-potential to relax their structures, and finally validating the results with first-principles calculations. We identify 5 stable and near-stable Y-Mn-B phases along with 61 metastable compounds with the formation energy within 100 meV/atom with respect to the ternary convex hull. Among them, Y2Mn7B7 and YMn4B4 are structurally analogous to the previously synthesized $R_{1+\epsilon}Fe_4B_4$ 1D incommensurate composite chain compounds. In striking contrast to the strongly suppressed Fe moments reported, our first-principles calculations reveal that the predicted Mn-chain phases preserve sizable local Mn moments (approximately 1.1 $\mu_B$) and favored
ferromagnetic ordering. Electronic structure analyses elucidate the microscopic origin of moment recovery via an enhanced exchange splitting driven by a Stoner-like instability. We also perform systematic Mn-Fe substitution to confirm the thermodynamic continuity and a monotonic enhancement of the macroscopic magnetization, from Fe to Mn. These findings indicate that targeted transition-metal substitution within a one-dimensional boride family can recover transition-metal magnetism, offering a physically interpretable route for designing new
magnetic rare-earth transition-metal borides.
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All authors Weiyi Xia, Wei Shen Tee, Maxim Moraru, Ying Wai Li, Cai-Zhuang Wang
Mathematical Physics
A Projected Semiexplicit Integrator for Dissipative Systems with Configuration-Dependent Kinetic Energy: Contact-Herglotz Formulation and Benchmarks
Lorena Loera-Galeana, Santiago Mejía, Espartaco Alvarado et al. (+1 more)
Contact
Hamiltonian dynamics gives dissipative mechanics an intrinsic action variable, but explicit contact splittings reach only kinetic energies whose terms are exactly integrable: frozen-coordinate diagonal metrics (the spherical pendulum, a
torus particle) are included, while dense metrics with momentum cross terms, with the double pendulum as flagship, are not. We introduce a projected Pihajoki-contact integrator for this non-separable setting, combining phase-space duplication, symmetric projection onto the physical diagonal, and constant-friction damping half-steps, with the action factor carried by an exact Herglotz update. As in the projected extended-phase-space framework it builds on, the construction needs no binding parameter, returns the copies to the diagonal at every step, and confines the nonlinear solve to the $2n$ projection variables. For constant friction the step rescales $\omega=d\eta$ by the exact factor $e^{-\gamma\tau}$ when the projection is solved exactly (a classical conformally
symplectic identity, realized here for this class), while time-
symmetry, consistency, and smoothness yield an $O(\tau^3)$ one-step contact-form residual, a bound not specific to the contact form. On the damped double pendulum, spherical pendulum, and
torus particle the method is second-order accurate, reproduces the contact decay law, and controls long-time energy and contact drift in coarse or stiff regimes where the Tao baseline and the unprojected average lose the solution. A head-to-head with exact-contactomorphism splittings delimits the niche: where a frozen-coordinate splitting exists it preserves the contact form exactly and wins at matched cost; for the dense double-pendulum metric the realizable alternative is first-order with a prohibitive constant and the projected method prevails. The contact-form estimate is local, one-step, and constant-friction.
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All authors Lorena Loera-Galeana, Santiago Mejía, Espartaco Alvarado, Héctor Medel-Cobaxin
Adaptation and Self-Organizing Systems
Phase-based spatial ordinal patterns for characterizing oscillatory dynamics
Robison J. Santos-Silva, Bruno R. R. Boaretto, Thiago L. Prado et al. (+1 more)
The emergence of organized spatiotemporal patterns is ubiquitous in oscillatory systems, from neural populations to engineered networks. Identifying these patterns and tracking how they evolve over time remains challenging, particularly when systems exhibit transient dynamics. Here, we introduce a framework based on spatial ordinal patterns to characterize the spatiotemporal dynamics of oscillatory systems. Our approach acts directly on the phase rather than the amplitude, with additional patterns introduced to account for near-equal phases. This symbolic representation encodes local spatial ordering relations, capturing both phase gradients and synchronized clusters within a single framework. From this construction, we define a spatial permutation
entropy that quantifies the diversity of spatiotemporal patterns at each point in time, enabling the detection of transient dynamics and regime transitions as they occur. We show that this approach distinguishes phase-locked states with identical levels of global synchronization but distinct spatial organization and also characterizes partially synchronized states. We demonstrate the method on synthetic oscillator networks across multiple spatiotemporal regimes, and on resting-state
EEG recordings from human volunteers, where it distinguishes different conditions within individual volunteers.
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All authors Robison J. Santos-Silva, Bruno R. R. Boaretto, Thiago L. Prado, Roberto C. Budzinski
Quantum Physics
Fast Nondestructive Readout for High-Clock-Rate Atom Array Quantum Processor
Xu-Zhao-Qiu Zeng, Chang You, Qing-Wei Wang et al. (+18 more)
Neutral-atom arrays have rapidly advanced to support thousands of
qubits and execute high-fidelity logical operations. However, these processors remain severely throttled by their slowest fundamental operation: nondestructive
qubit measurement, which requires milliseconds and fundamentally limits the system's clock rate. This bottleneck arises from both an inherent
photon-budget dilemma—sufficient fluorescence for reliable state discrimination must be collected without excessive heating or loss—and frame-based imaging, which imposes one common exposure and decision latency on intrinsically independent, site-local measurements. Here, we overcome these limitations with a fast, nondestructive readout architecture based on real-time, site-resolved adaptive protection. By integrating continuous
photon counting with a dynamic feedforward framework, we decode
qubit states with sub-microsecond latency and instantly shield atoms from redundant scattering. Demonstrated in parallel across a 100-
qubit reconfigurable atom array, with adaptive protection on a 25-site subarray, this dynamic decision protocol reduces the average probe time to just $15\ \mu\text{s}$. Model-free benchmarking yields a discrimination infidelity of $4.1 \times 10^{-5}$ and an atom loss of $2.1 \times 10^{-4}$, simultaneously setting new performance records for atom arrays. Exploiting this capability, we operate repeated
quantum circuits at an unprecedented 1.7 kHz clock rate with atoms reused over 120 consecutive rounds—nearly sevenfold higher than the previous record—and enter the sub-millisecond cycle regime for the first time. By removing nondestructive readout as the dominant cycle-time bottleneck, this work unlocks high-clock-rate mid-
circuit syndrome extraction, paving the way for high-throughput, fault-tolerant
quantum computation.
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All authors Xu-Zhao-Qiu Zeng, Chang You, Qing-Wei Wang, Zi-Feng Li, Yi Ji, Dong An, Chao Yu, Jia-Rui Liu, Zi-Mo He, Jia-Rui Gu, Yuhao Mei, Hao-Wen Cheng, Yu-Chen Zhang, Rui Lin, Zhan Wu, Jun Rui, Jun Zhang, Ming-Cheng Chen, Yu-Hao Deng, Chao-Yang Lu, Jian-Wei Pan
Fluid Dynamics
Autonomous route to the strange attractor: the many life stages of the chaotic bubblewheel
Michael Zhao and Saverio E. Spagnolie
A body floating atop a supersaturated fluid may accumulate bubbles along its underbelly, which can render the body rotationally unstable. But rotation can strip the surface of these bubbles when they make contact with the air above. To explore this coupling we perform experiments using cylinders floating on carbonated water. The cylinders exhibit an array of distinct dynamics, including constant rolling, periodic and aperiodic oscillation, chaos, and intermittent capsizing, which can be tuned by body size, mass distribution, and gas concentration. A continuum model for the bubble density dynamics, and Galerkin projection, tie the experiment to the generalized Lorenz system and its famed chaotic attractor. Even an extremely small center-of-mass offset can have a qualitative impact on the dynamics, and an offset of as little as a few percent can fully stabilize the system. The experiment represents a highly accessible physical realization of the Lorenz system, which, owing to continuous gas loss from the fluid to the air above, sweeps slowly without intervention across a classical bifurcation diagram in time.
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High Energy Physics (Phenomenology)
Closed-form expressions for tree-level gluon-gluon scattering: a framework for obtaining theoretical systematic uncertainties for jet-medium Monte Carlo simulations
Lukas Opitz, Hemanth Regi and Gojko Vujanovic
Modern
Bayesian theory-to-data comparisons for jet-medium interactions, such as [Phys. Rev. C 111,054913 (2025)], are lacking the careful accounting of theoretical systematic uncertainties included within their uncertainty budget. Tree-level
gluon-
gluon scattering is revisited to establish a framework capable of quantifying theoretical systematic uncertainties to be used in
Bayesian jet-medium constraints. The behavior of tree-level scattering in thermal QCD is examined in detail, finding deviations away from the commonly used approximations. Deviations in the scattering rate affect jet-medium transport coefficients at the partonic level, leading to a more intricate kinematic dependence for $\hat q$ and $\hat e$ than, say, the well-known logarithmic behavior. These deviations away from well-known behavior are used to estimate theoretical systematic uncertainties in
Bayesian analysis.
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High Energy Physics (Phenomenology)
The high-energy behavior of tree-level scattering in finite-temperature QCD: estimates of theoretical systematic uncertainty in jet-medium Monte Carlo simulations
Lukas Opitz, Hemanth Regi and Gojko Vujanovic
We examine the behavior of tree-level scattering in thermal QCD at high energies and find significant deviations away from the commonly used approximations [Phys. Rev. D 44, 1298 (1991), Phys. Rev. D 44, R2625 (1991), Phys. Rev. D.77, 014015 (2008), Phys. Rev. D. 77.114017 (2008)]. These deviations in the scattering rate also affect jet-medium transport coefficients at the partonic level, leading to a different kinematic dependence of the transverse momentum broadening per unit length $\hat{q}$. As scattering rates and $\hat{q}$ are used by large-scale Monte Carlo simulations of jets in the
quark-
gluon plasma (QGP), such as [Phys. Rev. C 111,054913 (2025)], current constraints on $\hat q$ are biased owing to the approximations used therein. Besides theoretically improving $\hat q$, the differences between the $\hat q$ herein and the approximate $\hat q$ used in jet Monte Carlo simulations are used to construct a theoretical systematic uncertainty, which in turn can be employed to devise a covariance
matrix for $\hat q$ and enables updating the uncertainty bands on $\hat q$ obtained by
Bayesian analysis.
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General Relativity and Quantum Cosmology
Rational regular black holes in non-polynomial gravity
Aimeric Colléaux
We consider the $d\geq 4$ non-
polynomial pure
gravity theories defined so that their 2D reduction to spherical
symmetry minimally modifies that of General Relativity at small distances. They satisfy Birkhoff
theorem and admit exact black hole solutions for an arbitrary number of couplings. These solutions have a logarithmic leading correction to the
entropy and a
quantum-like correction to the Newtonian potential, both arising from the regularised critical order $d=2p$ theory, which is related in even dimensions to the Euler characteristic of the 2D orbit space. These black holes can be made regular, without the need for infinite towers of corrections, using invariants of any order $p>d/2$. In even dimensions, their smoothness is linear in the number of corrections and does not require fine-tuning. We construct a class of theories admitting as unique (massless)
vacuum an extremal black hole deformation of (A)dS$_4$ or M$_4$ with vanishing
entropy, so that Nernst's third law of thermodynamics is satisfied without discontinuity in the
entropy. We show that a Maxwell field does not disrupt the regularity of the metric, and that simple non-minimal couplings in the action enable to regularise the electric field. Considering infinite towers of corrections, we construct quasi-regular black holes with one horizon as well as regular (A)dS-core ones with a near-extremal inner horizon for any mass. When charged, these two types of black holes prevent or tame the mass inflation provided the mass and charge satisfy an inequality of the form $M > \alpha \ell + \beta Q^2 / \ell$, where $\alpha$ and $\beta$ are numerical factors depending on the specific model, while $\ell$ is the length scale controlling the high-energy corrections. The quasi-regular black holes are sufficient to resolve the Coulomb singularity without the need for non-minimal couplings.
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Statistical Mechanics · Cross-listed from math.AP
Fixed-particle-number optimizers for the Lieb–Oxford inequality
Matthew Rosenzweig
Let $\mathsf{d}\geq1$, $0<\mathsf{s}<\mathsf{d}$, and $N\geq1$. We prove that the optimal fixed-particle-number constant $\Lambda_N(\mathsf{s},\mathsf{d})$ in the Riesz Lieb–Oxford inequality is attained and that these constants are strictly increasing in $N$. The proof combines grand-canonical concentration–compactness with a strict one-particle extension. After recentering, a limiting plan arising from a maximizing sequence may assign positive probability to several particle numbers and hence be grand-canonical. A strict $N$-particle completion excludes this case, while the inequalities $\Lambda_N>\Lambda_k$ for $k<N$ exclude limits with a fixed lower particle number. Once attainment at particle number $N$ is known, the compact-support
theorem of Di Marino and Lelotte arXiv:2607.11440, valid for all $0<\mathsf{s}<\mathsf{d}$, permits a non-product one-particle extension and yields $\Lambda_{N+1}(\mathsf{s},\mathsf{d})>\Lambda_N(\mathsf{s},\mathsf{d})$. Together, these implications close an induction beginning at $N=1$.
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Instrumentation and Methods for Astrophysics
The Roman Coronagraph Community Participation Program: target database and tools
Dmitry Savransky, Rifah Tasnim, Saanika Choudhary et al. (+13 more)
The Nancy Grace Roman Space
Telescope, set to launch in Fall 2026, will carry the Coronagraph Instrument, which will, for the first time, demonstrate high-contrast imaging with active wavefront control in visible wavelengths from space. In preparation for execution of the Coronagraph's commissioning and observing programs, the Roman Coronagraph Community Participation Program (CPP) has developed a target database and associated ecosystem of publicly accessible tools for observation planning and scheduling. The target database includes both
stars and known sub-
stellar companions and disks that may be observed by the Coronagraph instrument during its primary mission. Targets in the database include
planet and disk hosts as well as calibration
stars, reference
stars, and engineering program targets. The database is designed to operate in conjunction with a variety of tools, including an exposure time calculator, a pointing and keepout calculator, and a reference
star selection tool. Here, we describe the current schema and contents of the database and demonstrate how it and its associated tools are being used for observation planning.
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All authors Dmitry Savransky, Rifah Tasnim, Saanika Choudhary, Hovik Grigoryan, Justin Hom, Bijan Nemati, Neil Zimmerman, Ramya Anche, Nicholas Phillips, Louie Donesa, Parth Mittal, Amira Razack, Savaas Iqbal, Javier Majumdar, Schuyler G. Wolff, Vanessa P. Bailey
Materials Science
Temperature-Induced Reorganization of Supported Zn$_3$ Clusters on Cu(111): From Minimum-Energy Structures to Finite-Temperature Ensembles
Jiayan Xu, Zheng Yu, Abhirup Patra et al. (+4 more)
Understanding the nature of catalytic active sites under reaction conditions remains a central challenge in heterogeneous catalysis. In industrial copper/zinc
oxide/alumina catalysts for methanol synthesis, small Zn-based species at the Cu interface have long been proposed as active-site candidates, yet their atomic-scale structure and stability remain controversial. Computational studies typically identify such species from optimized 0 K structures, assuming that minimum-energy configurations remain representative under reaction conditions. Here, we combine machine-learning-interatomic-potential-accelerated global optimization, molecular dynamics, and enhanced-sampling free-energy calculations to investigate supported Zn$_3$(OH)$_3$ and Zn$_3$(OH)$_2$CHOO clusters on Cu(111)-based surfaces from 0 to 450 K. While compact triangular configurations are generally favored among minimum-energy structures at 0 K, finite-temperature free-energy calculations reveal a pronounced shift toward extended linear configurations with increasing temperature. This transition is driven primarily by entropic stabilization and cannot be inferred from potential energies alone. Molecular dynamics further shows substantial cluster mobility on pristine Cu(111), indicating that long-term persistence depends not only on configurational stability but also on surface mobility. Surface Zn alloying strongly suppresses
diffusion, thereby stabilizing isolated interfacial Zn species. Together, these results show that thermodynamically relevant structures of supported Zn-based clusters can differ fundamentally from static 0 K predictions because of competing enthalpic and entropic effects. Our findings highlight the limitations of identifying catalytic active sites solely from 0 K structures and underscore the importance of explicit finite-temperature sampling in catalyst modeling.
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All authors Jiayan Xu, Zheng Yu, Abhirup Patra, Amar Deep Pathak, Sharan Shetty, Detlef Hohl, Roberto Car
Quantum Physics
Gate-level Implementation and Resource Analysis of Lackadaisical Quantum Walk Search
Amit Saha, Debanjan Kola, Nishanka Das et al. (+1 more)
Lackadaisical
quantum walks (LQW) extend discrete-time
quantum walks (DTQW) by introducing weighted self-loops, enabling improved spatial-search performance through controlled localization of the walker. Despite substantial theoretical progress, practical gate-level implementations suitable for
quantum hardware remain largely unexplored, limiting evaluation under realistic architectural constraints, noise, and resource requirements. In this work, we present a gate-level implementation framework for lackadaisical
quantum walk search. The proposed construction encodes the position and coin spaces into
qubit registers, and realizes the walk dynamics through oracle, coin, and flip-flop shift operations. We validate the
circuit by reproducing the expected search behavior for single and multiple marked vertices and by analyzing the effect of the self-loop weight on the success probability. We further evaluate the implementation under realistic noisy settings using superconducting hardware's noise models. Logical resource analysis shows that, for grids ranging from $8\times8$ to $64\times64$, the transpiled gate count increases from $3.63\times10^{5}$ to $4.38\times10^{6}$ and the
circuit depth from $2.13\times10^{5}$ to $2.56\times10^{6}$. Finally, fault-tolerant resource estimates based on a surface-code model using the Microsoft
Quantum Resource
Estimator demonstrate the substantial space-time trade-off associated with magic-state production. The results establish a practical
circuit-level pathway for implementing the LQW search and provide a basis for evaluating its performance.
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All authors Amit Saha, Debanjan Kola, Nishanka Das, Amlan Chakrabarti
Statistical Mechanics · Cross-listed from cs.LG
Iterative tensor network transformations for element-wise evaluation of elementary and filtering functions
Xiao Wang, Tomohiro Hashizume, Pia Siegl et al. (+1 more)
Tensor networks are powerful formats for compressing large-scale data. However, their application to general data processing has been limited by the difficulty of performing nonlinear operations. Here, we introduce iterative tensor network transformations (ITNTs), a general algorithmic framework for the element-wise evaluation of elementary and nonlinear filtering functions on data encoded as tensor trains (TTs), a class of tensor networks. Our approach operates entirely in the compressed domain, enabling efficient computation on exponentially large
datasets while maintaining a controlled computational cost. We demonstrate its power in two key areas: (I) evaluating highly nonlinear elementary and filtering functions on a 3D reactive flow field, enabling high-fidelity reaction rate computation and region filtering, and (II) finding extrema in complex optimization problems, such as solving Max-SAT instances on spaces up to $2^{70}$ configurations. These results establish ITNT as a foundational tool that provides tensor network methods with the capability for general-purpose data science and large-scale optimization.
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All authors Xiao Wang, Tomohiro Hashizume, Pia Siegl, Dieter Jaksch
Instrumentation and Methods for Astrophysics
The Roman Coronagraph Community Participation Program: Observation planning and data reduction for polarimetric mode
Ramya M Anche, Toshiyuki Mizuki, Justin Hom et al. (+25 more)
Reflected-light polarimetry of
exoplanets constrains and resolves degeneracies in atmospheric properties, while polarized light observations of debris disks enable the characterization of
dust-grain properties. The best-effort polarimetric mode of the Roman Coronagraph Instrument will be able to perform multi-wavelength observations of planetary systems using both the Hybrid Lyot Coronagraph (HLC) and the Shaped Pupil Coronagraph (SPC). This paper presents an overview of observation planning, simulations, and data reduction procedures for the polarimetric mode of the Roman Coronagraph. As an initial test of simulation and data reduction, a
dataset of polarimetric observing sequences for the debris disk HD 172555 in HLC mode was generated using corgisim with estimated observation parameters, and data reduction was performed using corgidrp, incorporating all relevant noise factors and calibration products. Currently, mock calibration products are used in corgidrp; these will be replaced with simulated calibration products in future updates
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All authors Ramya M Anche, Toshiyuki Mizuki, Justin Hom, Alexis Lau, Saanika Choudhary, Jaren N. Ashcraft, Clarissa Do O, Tsutsumi Nagai, Sophie Noiret, Eric Shen, Taichi Uyama, Chen Xie, Jingwen Zhang, Vanessa P. Bailey, Eric Cady, Jessica Gersh-Range, Julien H. Girard, Guillermo Gonzalez, John Livingston, Bertrand Mennesson, Maxwell A. Millar-Blanchaer, Julia Milton, Naoshi Murakami, Dmitry Savransky, Motohide Tamura, Jason J. Wang, Schuyler G. Wolff, Marie Ygouf
Computational Physics · Cross-listed from cs.CE
Reduced-Order Physics-Informed Neural Network with Adaptive Basis Refinement for Structural Identification
Rui Zhang, Konstantinos Vlachas and Eleni Chatzi
Physics-informed neural networks (PINNs) provide a flexible framework for solving forward and inverse problems. However, their direct application to structural dynamics remains limited by high system dimensionality and model-form errors arising from incomplete physics. Reduced-order models (ROMs) can alleviate the dimensionality bottleneck, yet existing PINN-ROM couplings typically rely on fixed reduced subspaces, target forward simulations, or assume complete physics, restricting their use for inverse identification under parametric variability or incomplete system knowledge. To address these limitations, this work proposes a Reduced-Order Physics-Informed Neural Network (RO-PINN) framework with adaptive basis refinement for structural identification under known and incomplete physics. Via projection, reduced governing equations are embedded directly into the PINN loss, facilitating learning in a low-dimensional latent space. An adaptive scheme updates the projection basis during training so that the latent space is progressively realigned with evolving structural parameters or learned residual restoring forces. This realignment reduces basis-mismatch errors and limits their influence on the inferred residual force. The method is validated on a four-story steel frame with nonlinear hysteretic braces under sparse and noisy measurements. Results show parameter identification comparable to or more accurate than
Bayesian model updating with lower computational cost in the considered cases, recovery of unmodeled nonlinear restoring forces under incomplete physics, and joint identification of residual restoring forces and structural parameters within the same framework. Overall, RO-PINN provides a unified framework for structural identification by integrating reduced-order modeling, adaptive basis refinement, and physics-informed learning within a single formulation.
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