Computational Physics
Representation-split Carleman lattice Boltzmann with near-unit step success probability on quantum computers
Hua-Dong Yao and Sauro Succi
The Carleman
lattice Boltzmann method replaces the quadratic collision of the
lattice Boltzmann equation by a linear map on a lifted state. Existing block encodings of this map succeed with probability $10^{-5}$ to $10^{-2}$ per step, so that the probability of a multi-step
evolution decays exponentially with the number of steps. This study develops multi-relaxation-time Carleman
lattice Boltzmann, a representation split in which the Carleman-lifted collision is performed in a moment basis on the amplitude-encoded state, while streaming remains a permutation in population space. The level-2 hierarchy closes under collision but not under streaming, which generates the work of pressure, advection and stress on the momentum flux. The state therefore remains the full pair array, and the moment representation is an orthogonal change of basis of the population one, with identical dynamics and truncation error. The operator to be block encoded changes with the basis, and with it the success probability of a
quantum step. In the weighted Hermite basis with the amplitude encoding $f_i/\sqrt{w_i}$, the relaxation is a diagonal operator of norm one, and the level-2 collision stage becomes this diagonal plus a sparse coupling from products of conserved moments. A structured block encoding of this form raises the single-step success probability on the D2Q9
lattice from $10^{-2}$ for the best population encoding to 0.98. With the pair sector in relative coordinates and scaled, one step requires $O(\log^2 N)$ Toffoli gates and is verified by statevector simulation. The encoding and readout overhead of a $T$-step run is then
polynomial in $T$ and $N$ rather than accumulating a factor $p^T$. For resolved flows, the remaining exponential loss in coherent multi-step Carleman
lattice Boltzmann
evolution is set by the non-
equilibrium norm relaxed by dissipation rather than by the block encoding.
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Materials Science
Transferable Graph Neural Network Surrogates for Molecular Dynamics Across Crystal Symmetries
Judah Immanuel, Avik Mahata and Aniruddha Maiti
We present a transferable graph neural network (GNN) surrogate framework for molecular dynamics (MD) that directly predicts atomic displacements and propagates atomistic configurations without explicit force evaluation or numerical time integration. The central objective of this work is to establish whether a common GNN formulation can represent atomic dynamics across materials with fundamentally different
crystal symmetries and coordination environments. The same network architecture, feature representation, graph construction, and training protocol are applied without
symmetry-specific modification to face-centered cubic (FCC) aluminum, body-centered cubic (BCC) iron, and hexagonal close-packed (HCP) magnesium. Across these distinct elemental and crystallographic systems, the framework achieves position-prediction errors on the order of 10^-4 Angstrom^2 and supports stable autoregressive propagation to nanosecond time scales. The predicted trajectories preserve thermodynamic stability, characteristic coordination-shell structure in the radial distribution functions, and temperature-dependent mean-squared-displacement behavior. In particular, the framework captures the closely spaced coordination shells of BCC iron and the anisotropic coordination environment of HCP magnesium without introducing
lattice-specific representations. These results demonstrate that direct GNN-based atomic propagation can be formulated as a transferable framework across different elements,
lattice symmetries, and coordination geometries, providing a pathway toward generalizable surrogate models for accelerated molecular dynamics.
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Data Analysis and Statistics
A State-Transition Information Space for Time-Series Dynamics: Theory and Application
Dragutin T Mihailović, Vijay P. Singh and Slavica Malinović-Milićević
Characterizing dynamical organization in time series requires distinguishing the diversity of accessible states from uncertainty in their temporal transitions. Here we introduce a state-transition information space based on two normalized
entropy measures derived from ordinal patterns: K_q, quantifying ordinal-state diversity, and K_t, quantifying transition uncertainty. Their joint K_t-K_q representation provides a two-dimensional framework in which dynamical regimes and their temporal
evolution can be examined. Theoretical properties establish the bounded relation 0 <= K_t <= K_q <= 1, while canonical time series identify distinct empirical domains ranging from ordered dynamics to near-maximal randomness. Sliding-window analysis further shows that systems can exhibit temporal trajectories through the K_t-K_q plane rather than remaining at a fixed dynamical state. Application to 1,879 monthly naturalized streamflow records from the U.S. rivers shows that river dynamics occupy a distinct intermediate region between ordered and highly disordered regimes. Moreover, river positions shift systematically toward higher K_t and K_q with increasing drainage area, revealing scale-dependent organization of streamflow dynamics. The framework therefore provides a compact means of comparing state diversity, transition uncertainty, and their temporal and spatial organization across time-series systems.
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Astrophysics of Galaxies
SPHEREx 3.3 Micron Aromatic Emission in the Magellanic Clouds: Separating Dust Column, Excitation, and Environmental Suppression
Cheng Li
Bright emission in the 3.3um unidentified infrared band, often described as an aromatic infrared band, can trace
dust column, radiative excitation, or the survival and emissivity of its carriers. We combine SPHEREx maps of the Magellanic Clouds with HERITAGE
dust columns, a TIR heating proxy, Br\alpha, H\alpha, H II-region catalogs, and SAGE 8um imaging. We measure continuum-subtracted 3.3um feature excess, X_{3.3}, and Br\alpha excess, X_{Br\alpha}, in matched
cells. In each Cloud, a quiescent diffuse baseline depending on
dust surface density, \Sigma_d, and TIR/\Sigma_d predicts X_{3.3} with R^2=0.628 in the LMC and 0.288 in the SMC. Relative to this expectation, LMC H II interiors are under-luminous by -0.223^{+0.035}_{-0.040} dex; local-background measurements give -0.153^{+0.014}_{-0.043} dex despite a total-X_{3.3} enhancement of +0.749 dex. SMC H II-region residuals are consistent with zero over its lower-X_{Br\alpha} regime. A matched comparison with
stellar-subtracted 8um
dust intensity, I_{8,
dust}, shows that column and heating predict I_{8,
dust} more tightly than X_{3.3}, and that the high-X_{Br\alpha} LMC deficit is stronger for X_{3.3} than for I_{8,
dust}. The deficit is therefore selective to the isolated 3.3um feature, not uniform in all aromatic-band-dominated emission. This result suggests that the small aromatic/aliphatic carbonaceous carriers traced by the isolated 3.3um feature are more susceptible to processing in active regions than the larger or differently emitting carbonaceous-grain population dominating the 8um aromatic complexes.
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General Relativity and Quantum Cosmology
Non-equilibrium thermodynamics of an expanding Swiss-Cheese braneworld cosmology with a matter bounce
Nasr Ahmed
We investigate the non-
equilibrium thermodynamics of a Swiss-cheese (SC) braneworld universe. By employing Hayward's unified first law and the Clausius relation at the apparent horizon, we first show that the standard
equilibrium treatment of the effective SC braneworld fluid, together with the usual Hawking temperature, reproduces the Bekenstein-Hawking area law without any braneworld correction to the
entropy. This demonstrates that the brane quadratic energy density corrections cannot, by themselves, generate a modified
entropy area relation within the
equilibrium framework. We therefore formulate a non-
equilibrium thermodynamic description in which deviations from the Bekenstein-Hawking
entropy are accompanied by an internal
entropy production term. For a general horizon
entropy functional, we derive the corresponding
entropy production rate and then specialize to a logarithmic and inverse area
quantum-corrected
entropy. The resulting irreversible contribution is expressed in terms of the Hubble parameter and its derivative. We apply the formalism to a nonsingular matter-bounce solution in the SC braneworld. During the expanding phase, the total
entropy production remains positive satisfying the GSLT. Moreover, the late-time behavior of the second derivative of the total
entropy becomes negative, indicating a decelerating
entropy growth and an asymptotic approach toward thermodynamic
equilibrium. Far from the bounce, the equation of state parameter $w \approx -1$, indicating a dark energy-dominated regime. Significant departures from $w = -1$ are confined to the bounce vicinity, where high energy braneworld corrections drive the nonsingular transition. Thus, the model naturally transitions from a high energy bounce into an asymptotic dark energy phase during late-time expansion.
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Atmospheric and Oceanic Physics
Scale analysis for the Madden$-$Julian oscillation
Hing Ong
This study performs a scale analysis for the dynamics of equatorial flow systems like the Madden$-$Julian oscillation (MJO). This analysis makes three assumptions about the geometry of the flow and focuses on the leading order terms of the mass continuity and momentum equation system. First, the flow is meridionally narrow. Second, the zonal structure is planetary wavenumber 1. Last, the flow is vertically shallow. When constrained by these
geometric assumptions, the system shows a time scale much longer than a day depending on the meridional narrowness. Specifically, for equatorial Kelvin waves, the oscillation period ranges from 36 to 64 days given a ratio of the planetary radius to the meridional width scale from 6 to 8 (i.e., an e-folding latitude from 9.59$^\circ$ to 7.18$^\circ$ either side of the equator). Given the long, narrow, and shallow geometry, the dynamics can sustain Kelvin waves only at low frequencies. This result suggests that the intraseasonal time scale of the MJO arises from the Kelvin wave frequency limit due to the planetary wave geometry. This planetary intraseasonal scale relation is independent from thermodynamics, and an open question remains on what physical processes coordinate the thermodynamics in the same length or time scale.
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Geophysics
Large-scale bioacoustic detection using semantic segmentation: a deep learning framework applied to fin whale calls in ocean-bottom seismometer recordings
Jocelyn Japnanto, Alex A. Saoulis, Miriam Romagosa et al. (+5 more)
Ocean-bottom seismometers (OBS), originally deployed for geophysical research, continuously record low-frequency sound for months to years across broad areas of ocean, offering a largely untapped resource for passive acoustic monitoring (PAM) of baleen whales. Realising this potential requires automated detection methods that operate reliably across the varied conditions in large sensor networks. We present a deep learning semantic
segmentation framework that detects the 20-Hz notes of fin whales (Balaenoptera physalus) in OBS spectrograms, assigning each pixel a probability of belonging to a call and converting the resulting probability maps into time-frequency bounding boxes describing individual detections. We trained the model on hydrophone data from one OBS deployment in the Azores-Madeira-Canaries region and applied it without retraining to vertical-component seismometer data from a second, geographically distinct deployment, showing that a single trained model generalises across sensor types and recording environments. Applied to 378,912 h of recordings from 46 OBS sites, the detector identified 6.3 million calls, forming the largest fin whale call catalogue assembled to date, with high precision (~97%) across both deployments. The resulting catalogue resolves call timing and spectral structure accurately enough to support ecological analyses, revealing coherent seasonal shifts in three persistent inter-note interval (INI) groups across the singing season and basin-scale patterns in calling activity. By transforming existing geophysical infrastructure into a scalable sensing network, our approach substantially expands the spatial and temporal reach of PAM without new hardware investment, offering a transferable framework for tracking other low-frequency vocalising species and informing conservation planning, marine spatial management, and abundance estimation across large scales.
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All authors Jocelyn Japnanto, Alex A. Saoulis, Miriam Romagosa, Rita Leitão, Gabrielle Arrieta, Mónica A. Silva, Matthew Graham, Ana M. G. Ferreira
Chaotic Dynamics
Tensor-Based Chaotic Perception
Amir M. Majd
Symbols can provide compact representations of complex sensory information. Mathematically, chaotic attractors can provide a basis for such representations, with object identity encoded in the topological organization of the attractor. In three-dimensional phase space, this organization can be characterized by the linking
matrix of unstable periodic orbits, which serves as a topological fingerprint. Because the linking
matrix has no closed-form dependence on the learnable parameters, we learn the chaotic series generating the target attractors rather than optimizing the invariant directly; the reconstructed attractor then determines its unstable periodic orbits and linking
matrix through its
topology. In this paper, we propose a third-order tensor that maps inputs to connection
matrices that generate the corresponding chaotic series. Exploiting the duality between a vector and its sequential representation as a series, we lift inputs into a higher-dimensional space and reorder their components, allowing the input to be presented sequentially rather than simultaneously. We first demonstrate that this representation can discriminate between classes in the \href{https://archive.ics.uci.edu/
dataset/151/connectionist+bench+sonar+mines+vs+rocks}{Sonar}
dataset. We then examine perceptual constancy using the \href{https://www.csc.kth.se/cvap/databases/kth-tips/index.html}{KTH-TIPS2-a}
dataset, where variations in color and texture within a class are mapped to distinct chaotic series associated with the same topological attractor class. The results demonstrate that the proposed tensor-based mapping can preserve attractor class while accommodating variations in the sensory realization of an object.
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Physics and Society
Assessment of Non-Institutional AI Tool Usage Among Clinicians
Sarah Pungitore and Jarrod Mosier
Generative artificial intelligence (AI) tools are increasingly accessible and have the potential to improve efficiency across clinical workflows. However, clinicians may also use non-institutional AI tools that are not provided, managed, or governed by their healthcare institutions, creating potential concerns related to
privacy, security, accuracy, and clinician-AI interaction. Little is known about how clinicians currently use these tools for work-related tasks. We conducted a descriptive survey of clinicians recruited from the University of Arizona College of Medicine-Tucson and Banner University Medical Center-Tucson between May 20 and June 26, 2026. Participants reported their use of AI tool categories and the frequency with which they used AI for specific tasks across five workload categories: administrative work, clinical work, research, studying/continued education, and teaching. Forty-four respondents completed the survey. Forty-three respondents reported using AI for at least one work-related task during the preceding 6 months. Conversational AI and clinical decision support/diagnostic AI were the most used tool categories, each reported by 28 respondents. Administrative and clinical tasks demonstrated the most frequent use. AI was also used for higher-risk activities, including diagnostic assistance and clinical decision support. Non-institutional AI use was common among surveyed clinicians and extended across a broad range of work-related activities, including tasks with potential implications for clinical
reasoning and patient care. Further research is needed to characterize how clinicians use these tools, how they evaluate AI-generated outputs, and how AI can be safely and effectively integrated into clinical workflows.
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Statistical Mechanics
Disordered hyperuniform modulated phases and the cosmic web from one free energy
Fausto Martelli
Disordered hyperuniformity spans twenty-five orders of magnitude, from the microscopic world of soft and condensed matter to the distribution of matter in the universe. We introduce a free-energy functional with no adjustable coupling, a phase-field-
crystal ordering term and a Newtonian tail, and show that its two kinetic limits generate two of these structures. Under conserved overdamped dynamics it arrests in a bicontinuous labyrinth of the kind found in confined fluids, block copolymers, active matter and vegetation patterns, which is a class III disordered hyperuniform state; under inertial dynamics in an expanding background it generates a
cosmic web whose
tidal skeleton matches that of
gravity alone to within $0.03$ in every morphological class. In both limits the suppressed long-wavelength fluctuations are inherited from the initial condition rather than made by the dynamics: the large-scale exponent of the arrested state equals the
primordial one, and
gravity rescales the infrared spectrum by the linear growth factor to better than one per cent over a factor $1363$ of growth. The two sectors are continuously connected, and their distance is measurable: once the ordering modulation saturates, its mean-field back-reaction leaves the medium with a residual pressure proportional to $\lambda_0^2$ that suppresses the growth of the largest scales by a smooth factor and vanishes in the cold-matter limit $\lambda_0\to0$.
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Mesoscale and Nanoscale Physics
Multiple Majorana zero modes realization based on superconducting topological crystalline metal ZrRuAs
Xiaoxu Wang, Jinyu Zou and Gang Xu
The
symmetry-protected multiple Majorana zero modes (MZMs) can be manipulated under external fields and have emerged as a promising pathway toward realizing topological
quantum computing. While the suitable materials hosting multiple MZMs are still scarce, we propose a feasible candidate platform named superconducting topological crystalline metals (STCMs) that simultaneously possess
symmetry-protected topological bands and intrinsic superconductivity. Model analyses demonstrate that the interplay among s-wave superconductivity, mirror
symmetry-protected multiple surface Dirac cones, and the introduced
spin splitting leads to high BdG Chern numbers of $\mathcal{N} = \pm C_M$, where $C_M$ is mirror Chern number of the STCM. First-principles calculations identify the experimentally synthesized
superconductor ZrRuAs as a promising candidate with $C_M=2$, hosting two
symmetry-protected surface Dirac cones. When integrated into a
heterostructure with the
ferromagnetic insulator (FMI) such as GdI$_{2}$, a topological superconducting phase with $\mathcal{N} = -2$ can be realized, giving rise to two branches of MZMs. This new scheme offers advantages of structural simplicity and tunability, making the FMI/STCM
heterostructure an ideal platform for investigating multipole MZMs and novel topological
qubit.
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Solar and Stellar Astrophysics
On modelling the 2017 galactic cosmic ray depression
O.P.M. Aslam, D. MacTaggart, M.S. Potgieter et al. (+2 more)
In the second half of 2017, as
Solar Cycle 24 approached its minimum, a pronounced and
rigidity-dependent depression in the
galactic cosmic ray (GCR)
proton flux was observed using AMS-02. This event was driven by a sequence of strong coronal mass ejections (CMEs). In this work, we model the modulation of GCR
protons during this period using a steady-state Parker transport framework with parameters constrained by AMS-02 observations. Treating the event as a purely long-term modulation interval yields excellent agreement with the observed
proton intensities, but implies an inferred
rigidity dependence of particle mean free paths that is inconsistent with basic
turbulence theory, corresponding to an effective inversion of the scattering regime. We argue that this behaviour arises from the ability of highly flexible transport parameterizations to reproduce integrated modulation signatures through correlated adjustments of
diffusion coefficients during transient events. To address this inconsistency, we relax the commonly adopted assumption of a time-independent ratio of perpendicular to parallel
diffusion coefficients and introduce a physically motivated reduction of this ratio during the CME-dominated interval. This modification preserves the quality of the spectral fits whilst restoring the expected
rigidity ordering of mean free paths. Our results indicate that allowing the perpendicular-to-parallel
diffusion ratio to vary in time provides an effective means of constraining transport solutions during the 2017 depression and may help to resolve similar inconsistencies reported in other GCR modulation studies.
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All authors O.P.M. Aslam, D. MacTaggart, M.S. Potgieter, M.D. Ngobeni, I.I. Ramokgaba
High Energy Physics (Theory)
Real-Time Instanton Dynamics in a Triple-Well to Double-Well Homotopy
Vojtěch Loubal, Tomáš Sýkora and Šimon Kos
We show that the singularities which the analytically continued double-well instanton develops in real (Minkowski) time are not an inherent feature of real-time tunneling solutions. Rather, they can be viewed as arising from a singular limit of a one-parameter family of regular real-time solutions. Using a linear homotopy between a triple-well and a double-well potential, we construct a family of potentials, parametrized by $p\in(0,1)$, whose real-time ($\alpha=0$) instanton solutions are everywhere regular and bounded. For any Wick rotation angle $\alpha\in(0,\pi/2)$, we prove that regularity is generic up to a measure-zero set. There exists a countably infinite, closed-form family of potential parameters $\{p^{\mathrm{singular}}_{k}(\alpha)\}_{k\geq0}$ at which the instanton becomes singular at exactly two points of the rotated time axis, never more. In the strict double-well limit, $p\to 1$ taken at $\alpha=0$, the entire family collapses onto the single point $(p,\alpha) = (1,0)$ at which the singular pairs of all $k$ occur simultaneously. This phenomenon produces the infinite singular comb found by Cherman and Ünsal. By solving the complexified equations of motion in terms of Weierstrass
elliptic functions, we trace this comb to classical imaginary turning points receding to $\pm\mathrm{i}\infty$, giving a unified
geometric and algebraic account of when, and exactly how often, real-time instantons become singular. We further show that the action of the continued instanton is independent of $\alpha$ only in its real part: its imaginary part jumps by one real-time period action at each singular angle, the $\alpha$-independence found by Cherman and Ünsal being the degenerate case of the double well, in which no such jump occurs.
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General Physics
Bound states in the continuum of gravitational waves
Rodrigo Berté
Bound states in the continuum (BICs) are ubiquitous wave phenomena, but have not yet been demonstrated for gravitational waves (GWs). Here, in-plane periodic perturbations, exponentially localized at the plane $z = 0$, are shown to lead to distributional surface energy tensors at this plane and to be regular
vacuum solutions ($T_{\mu \nu} = 0$) of the linearized Einstein field equations outside of it. These are achieved by explicitly calculating the
Ricci tensor components and the
Ricci scalar from the metric perturbation tensor. To fulfill each
vacuum solution ($R_{{\sigma \nu}_{(+, \times)}} = 0$ and $R_{{}_{(+, \times)}} = 0$), different surface polariton-like dispersions are required. These bound perturbations decay exponentially to a flat metric ($h_{{BIC}_{(+,\times)}} \propto e^{- k_z |z|}$), and each localized metric has a correspondence to a different planar GW polarization ($+,\times$). The Lorenz gauge-fulfilling solutions exist at the $\Gamma$ point in momentum space, dwelling within the continuum of wavevectors of propagating GWs. The strains in the unit
cell of the periodic perturbations have opposite parities relative to the corresponding planar GWs under a $C_2$ in-plane rotation, making them incompatible by
symmetry with their propagating counterpart, indicating localization via
symmetry protection.
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General Relativity and Quantum Cosmology
Emergence of Gravity's Dynamical and Topological Sectors from Pre-geometry
Andrea Addazi and Giuseppe Meluccio
We identify the complete set of fundamental building blocks for a 4D pre-
geometric theory of
gravity. Based on a gauge theory of $SO(1,4)$ or $SO(2,3)$ coupled to a
Higgs-like field under the rigid constraint of general covariance in the unbroken phase, these building blocks - $\mathcal{L}_\text{MM}$, $\mathcal{L}_\text{W}$, $\mathcal{L}_{J}$, $\mathcal{L}_\theta$ and $\mathcal{L}_\vartheta$ - constitute the minimal generating set of independent field monomials from which any pre-
geometric action, including arbitrary functionals thereof, can be constructed. While the most general pre-
geometric theory can extend beyond linear combinations, these five irreducible invariants serve as the 'atomic' constituents of all possible pre-
geometric dynamics. Upon spontaneous
symmetry breaking, they collectively generate an emergent gravitational theory consisting of the Einstein-
Hilbert action, the cosmological constant term and all 4D topological invariants: the Gauss-Bonnet, Pontryagin, Holst and Nieh-Yan terms. The unification of
gravity's dynamical and topological sectors from a common pre-
geometric source represents the central result of this work. We also uncover a see-saw mechanism linking the Planck mass and the cosmological constant, as well as several novel relations for the coupling constants of the topological sector, inclusive of the Barbero-Immirzi parameter. This framework establishes the pre-
geometric foundations from which all aspects of gravitation can dynamically emerge, providing a unified starting point for
quantum gravity, dark energy phenomenology and the study of topological phases in gravitational theories.
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Superconductivity
Generating is not discovering: a pre-registered physics judge for AI-proposed superconductors, calibrated on six known superconductors and one negative control
Reinaldo Inácio
Generative models now propose millions of "stable"
crystal structures, and their own referees have shown that stability is not discovery; no public
benchmark asks whether a candidate has the physics to do a job. For
superconductors the job is twofold: to pair, with a definite gap
symmetry, and to become wire. We present a physics judge that answers both from a structure alone (DFT+U, a gated Wannier model, the full rank-4 RPA susceptibility on a $24^3$ mesh, the linearized gap equation, an irreducible-representation classifier, a manufacturability funnel) and measure what it says about what generators propose. With answer keys pre-registered before computing, the judge was calibrated on six known
superconductors (Nb, Nb$_3$Sn, MgB$_2$, BaFe$_2$As$_2$, La$_{2-x}$Sr$_x$CuO$_4$, YBa$_2$Cu$_3$O$_7$), recovering the expected class in all six after two dated corrections. On the ruthenium analogue of the iron pnictide, with two runs and their criterion pre-registered the day before, it returns a null verdict at the same physical interaction where iron gives s$\pm$ ($\lambda_1 \le 0.0007$ versus 0.096; critical U 4.17 versus 0.97 eV); the pre-registered equal-alpha run fails the letter of the criterion, and we declare the resolution in favour of absolute U as post-hoc. The funnel reproduces the industrial map with thresholds fixed before running. Three generation audits follow: a descriptor sweep over 150 Materials Project metals re-finds the canon; 1,248 MatterGen structures yield 0 candidates that are new, stable and carry a pairing motif; mechanism filters over 47,893 compounds, validated by a blind hold-out, re-derive the community's analogies: geometry plus d-count is necessary but not sufficient. Generation re-finds what is known; judgment is the bottleneck. We propose a public
benchmark over the eleven lists of AI-proposed
superconductor candidates, none of which classifies gap
symmetry.
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Quantum Physics
When Measurement Constraints Favor Quantum Computational Sensing for Stealthy Power-Grid Attack Detection
Saisubramaniam Gopalakrishnan, Supreeth B S, Pranav Sarda et al. (+2 more)
Power-grid defenses that rely on digital telemetry remain vulnerable to stealthy attacks that preserve plausible reported states while altering the underlying physical system. We study when Nitrogen-Vacancy (NV) sensing provides a useful independent physical channel, and when coherent processing before measurement adds value. Across IEEE 14-, 30-, and 118-bus simulations with Lindblad NV models, we evaluate standard FDIA, BDD-stealth, statistical-stealth, and concealed
topology attacks. The results reveal an observability hierarchy: evidence shifts from digital telemetry, to reported-versus-physical consistency, to the physical NV state.
Quantum Computational Sensing (QCS) follows this selectivity, becoming informative only when the physical state itself carries attack evidence. We then compare QCS, conventional 4-setting NV readout, and
tomography under matched measurement budgets. At a matched total budget of only 40 physical trials per sensor on case14, QCS reaches AP $0.944$, versus 0.800 for conventional NV readout and 0.751 for
tomography; the same low-budget ordering holds on case30 and case118. Multi-setting methods recover as additional measurements become affordable, showing that the QCS benefit is a measurement-efficiency advantage rather than a universal accuracy advantage. Finally, we ask where the benefit varies across the three case simulations. Although the
quantum-to-classical Fisher-information ratio increases from 1.21x to 1.54x, Normal–Attack Helstrom separation collapses in the harder regimes, and interleaved control substantially increases that separation only on case14, thereby
quantum sensitivity does not necessarily imply task-relevant distinguishability. Our results show that realized QCS utility depends on the full chain from physical perturbation to state separation, coherent processing, and measurement under the resource constraints of the task.
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All authors Saisubramaniam Gopalakrishnan, Supreeth B S, Pranav Sarda, Ashesh Xalxo, Dagnachew Birru
Popular Physics
The Epistemic Risk of the 31st Spore: If Planets Aren't Fine Tuned, We're Doing Life Detection Wrong
Harrison B. Smith and Cole Mathis
Exploration of planetary bodies within our
solar system will be essential for understanding the origin of life on Earth and the distribution of life in the universe. Planetary protection policy is concerned with balancing this desire for exploration against the risks of contaminating alien
planets with Earth life, and contaminating Earth with alien life. However, at present, we have no fundamental scientific understanding of life's emergence or its nature beyond Earth. Given this nearly complete ignorance about the possibility of alien life, or Earth life's capacity to expand beyond our
planet, it is difficult to reason about the real risks of space exploration. Here we contend that contemporary understandings of the risks of forward contamination are based on arguments which inconsistently apply our incomplete knowledge to the problem. We reason that a more assertive posture towards space exploration, focused on determining whether other
planets in the
solar system are inhabited, is warranted and explain why such a posture may not increase the epistemic risks of planetary contamination. Finally, we explore the consequences of our arguments for planetary protection protocols, and life detection efforts.
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Astrophysics of Galaxies
Phase-Spirals Across Galactic Disks II: Using large-scale "macro-spirals" in phase-spiral amplitude to derive perturbation times
Kiyan Tavangar, Kathryn V. Johnston, Jason A.S. Hunt et al. (+3 more)
Phase-space spirals in the Milky Way disk are a key observable remnant of recent perturbations to the
Galaxy. They provide insight into the disk's potential, dynamical
evolution, past interactions, and even substructure. However, the complex dynamics of phase-spiral formation and
evolution have made clear interpretations challenging. For example, recent work has shown that the "winding time" – measured from how tightly wound a phase-spiral is – is a biased estimate of the true time since the inciting perturbation due to the complex effects of self-
gravity. In this paper series, we present an alternative approach by looking at correlations in phase-spiral morphology across the
Galactic disk. Here we show that following a localized perturbative event, the ridgeline connecting the largest amplitude phase-spiral at each radius winds up into a "macro-spiral" at the rate expected for differential rotation. This means the macro-spiral can 1) be unwound to constrain the origin – time and location – of correlated phase-spiral properties and 2) indicate the delay in individual phase-spiral winding as a novel diagnostic of disk dynamical properties. Applying these ideas to the Milky Way's phase-spirals, we estimate a perturbation time of $\simeq 1$ Gyr ago, consistent with the penultimate passage of the Sagittarius
dwarf galaxy through the disk, and delay times of up to 800 Myr for phase-spirals in the inner disk. While the current application of this method to
Gaia DR3 data is limited by the available radial velocities, future
Gaia data releases will enable stronger constraints using a much larger area of the
Galactic disk.
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All authors Kiyan Tavangar, Kathryn V. Johnston, Jason A.S. Hunt, Axel Widmark, Vandana G. Kaushik, Adrian M. Price-Whelan
High Energy Astrophysical Phenomena
First Detection of Radio Polarization During Jet Formation in the Changing-Look AGN 1ES 1927+654
Onic I. Shuvo, Eileen T. Meyer, Sibasish Laha et al. (+10 more)
We present a multiwavelength
radio study of the changing-look AGN 1ES 1927+654 following its renewed X-ray brightening since mid-2022, combining VLBA imaging with multi-band and time-resolved VLA observations. Our main results are: (i) VLBA observations continue to reveal the bipolar jet structure first reported in Meyer et al. (2025), with new X-band detections confirming the morphology at larger separation and K-band imaging revealing a bridge of emission consistent with a continuous
outflow; (ii) the VLBA core exhibits a GHz-peaked spectrum, and VLA/VLITE observations from 340 MHz to 45 GHz show emission from an inhomogeneous synchrotron source, self-absorbed below ~3 GHz and optically thin above; (iii) VLA and VLBA flux densities are consistent above 8 GHz, indicating emission dominated by a compact core; (iv) linear polarization is detected above ~3 GHz, with fractional polarization increasing with frequency from ~0.2% to ~6% and EVPAs exhibiting non-linear lambda^2 behavior; (v) long-term VLA X-band monitoring reveals a large, smooth rotation of the EVPA of ~137 degrees over ~81 days in 2026, followed by a partial return, at stable total intensity and suppressed fractional polarization <~1.4%, consistent with a propagating disturbance crossing the compact emitting region; and (vi) circular polarization is not detected at any epoch. These observations demonstrate that 1ES 1927+654 has transitioned from an X-ray-dominated, non-jetted state to a
radio-loud AGN (Laha et al. 2025) hosting a newly launched relativistic jet, a unique laboratory for studying jet birth and early
magnetic field
evolution.
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All authors Onic I. Shuvo, Eileen T. Meyer, Sibasish Laha, Agniva Roychowdhury, Dev R. Sadaula, Tracy E. Clarke, Wendy M. Peters, Mitchell C. Begelman, Markos Georganopoulos, Rostom Mbarek, Amelia M. Hankla, Alexander Philippov, Navin Sridhar
Soft Condensed Matter
Comprehensive molecular dynamics study of the dynamical properties of a dense binary hard-sphere mixture
Sabry G. Moustafa and Andrew J. Schultz
We present an extensive molecular dynamics (MD) study of the dynamical properties of a binary hard-sphere fluid over a wide range of packing fractions, $\phi \approx 0.357-0.582$. The self-diffusivity, $D$, and shear viscosity, $\eta$, are computed using an efficient implementation of the Einstein–Helfand method. The finite-size effects in $D$ scale as $1/N^\alpha$, with $\alpha$ increasing from approximately $1/3$ to $3/4$ with increasing $\phi$, whereas those in $\eta$ are negligible except for $\phi \gtrsim 0.554$, where they scale as $1/N$. The data are then extrapolated to the thermodynamic limit to obtain $D_{\infty}$ and $\eta_{\infty}$. Both coefficients show a super-Arrhenius dependence on $\phi$ for dense states, accompanied by a breakdown of the Stokes–Einstein relation. Although both $D_{\infty}(\phi)$ and $\eta_{\infty}(\phi)$ data are well described by an exponential form, we demonstrate that these fits do not provide reliable estimates of the critical packing fraction, $\phi_0$, owing to the substantial extrapolation required beyond the accessible
equilibrium range. We find the commonly assumed proportionality between $\eta$ and the structural relaxation time, $\tau_\alpha$ , to not hold for this system. For $\phi\gtrsim 0.570$, the van Hove self-correlation function $G_s(r, \tau)$ exhibits a spatial exponential decay at intermediate times, $\tau$, signaling dynamic heterogeneity. The characteristic decay length scales as $\lambda \sim \tau^\nu$, with $\nu \approx 1/3$, in contrast to the conventional square-root scaling. We also investigate temporal heterogeneity through the four-point dynamic susceptibility, $\chi_4(\tau)$, and its peak time, $\tau_4$. These findings provide rigorous
benchmark MD data for computational studies of glassy dynamics and establish a reference for testing theoretical models in dense disordered systems.
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General Relativity and Quantum Cosmology
From driven oscillations to free ringdown: a particle plunging into Kerr
Colin Weller, Andrew Laeuger, Fulin Li et al. (+5 more)
We show that a ringdown waveform can admit a constant-coefficient quasinormal-mode (QNM) representation while its individual QNM-pole contributions remain driven. To establish this result, we construct a first-principles rational approximation to the Kerr Green's function from its QNM poles, physical residues, and horizon-frequency zeros. For particles plunging from the innermost stable circular orbit into Kerr black holes with
spins 0.5-0.9, each QNM-pole contribution initially follows the source's instantaneous complex frequency and decouples only after the source decays faster than the corresponding mode. At late times, the source approaches a sum of damped oscillations at the third and higher horizon frequencies. The corresponding zeros in the Green's function cancel these source-frequency components in the coherent waveform, while the continuing drive generates oscillations at QNM frequencies. Thus, an apparently free QNM superposition can emerge before its individual contributions dynamically decouple from the source.
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All authors Colin Weller, Andrew Laeuger, Fulin Li, Neil Lu, Rowina S. Nathan, Sizheng Ma, Yanbei Chen, Ling Sun
Nuclear Theory
MUSES workflows for pQCD constraints on dense matter with finite quark masses
Isabella Danhoni, Mateus Reinke Pelicer, Débora Mroczek et al. (+3 more)
We present a modular implementation of next-to-leading order (NLO) perturbative QCD (pQCD) thermodynamics with finite strange
quark mass in the MUSES Calculation Engine, enabling reproducible connections between high-density QCD calculations and
neutron star observables. Using this implementation, we investigate the interplay between
flavor symmetry and physically motivated renormalization-scale prescriptions in cold, $\beta$-equilibrated
quark matter. We compare prescriptions associated with the conserved-charge $BQS$, isospin $BI_3S$, and $SU(3)$ Cartan $BI_3Y$ bases, and show that their different
symmetry properties at finite perturbative order can significantly affect the predicted
flavor composition. In particular, while the $BQS$ and $BI_3Y$ prescriptions yield the same reduced $\beta$-equilibrated \eos{} for $\mu_S=0$, they can predict different
flavor compositions, whereas the $BI_3S$ prescription generates additional contributions to the charge-neutrality condition and develops strong scale dependence at low chemical potentials. We then apply stability and causality constraints to investigate the effect of the strange
quark mass on the
neutron star \eos{}. In an exploratory
benchmark at $\mu_B=2.4$~GeV and fixed fiducial renormalization scale, increasing the fixed strange
quark mass from $m_s=0$ to $m_s=300$~MeV reduces the fraction of \eos{} in our prior that is incompatible with the pQCD constraint from 51% to 36% and qualitatively changes the region of \eos{} space that is selected, retaining greater support for stiffer behavior. These results motivate systematic studies of strange
quark mass and renormalization-scale uncertainties in pQCD constraints. The MUSES implementation provides a modular framework for such extensions and for future higher-order calculations.
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All authors Isabella Danhoni, Mateus Reinke Pelicer, Débora Mroczek, Yumu Yang, Mauricio Hippert, Jacquelyn Noronha-Hostler
Mathematical Physics · Cross-listed from math.DG
Conformal boundary rigidity for simple Finsler metrics
Kelvin Lam and Hanming Zhou
In this paper we prove that simple Finsler
manifolds are conformally stable. Given a simple Finsler
manifold and a class of conformal factors, we characterize the singularity of their induced boundary distance functions which allows us to define an appropiate $H^2$ norm. We then obtain a stability estimate with respect to this Sobolev norm and the $L^2$ norm on the class of the conformal factors. To prove the main
theorems, we adapt the classical integration by parts technique employed by Mukhometov \cite{Muhometov} to the Finsler setting.
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Atomic Physics
A metastable state in $\mathrm{Yb}^+$ with lifetime greater than 10 minutes
Hassan Farhat, William Liu and Wesley C. Campbell
We find through direct, time-domain measurement of trapped $\mathrm{Yb}^+$ ions that the excited ${}^3[11/2]_{9/2}^o$ state has a collision-free lifetime of 17.8(6) min, long enough for use in atomic clockwork or
quantum information processing. We locate and
benchmark a broad “repump” transition at $701\, \mathrm{nm}$ that readily transfers population back into the Doppler cooling cycle with the ground state, which may allow for
quantum nondemolition measurement of sub-structure in the metastable
manifold. Using a bi-stable Coulomb-
crystal manometer, we find that the collisional quenching of this metastable ${}^3[11/2]_{9/2}^o$
manifold by background gas is more efficient than for ${}^2\mathrm{F}_{7/2}^o$, but nonetheless we observe an average lifetime exceeding 10 minutes at the base pressure of our apparatus.
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Instrumentation and Detectors
Development and demonstration of the Korea ALICE Telescope using electron beams at KEK PF-AR
Jiyoung Kim, Meike Danisch, Sungwoon Choi et al. (+26 more)
The development of ultra-low-mass, high-precision vertex detectors is a key requirement for future
collider experiments and motivates extensive research and development of novel silicon tracking technologies. In this work, we present the development and beam-test demonstration of the Korea ALICE
Telescope (KATS), a silicon-tracking
telescope designed to support R&D on next-generation cylindrical vertex detectors, such as the proposed ALICE ITS3 upgrade. The
telescope consists of six ALPIDE Monolithic Active Pixel Sensors (MAPS) used as reference tracking planes, a bent ALPIDE sensor serving as the device under test, and a scintillating-fiber-based trigger system, all housed in a light-tight modular enclosure. This setup enables precise track reconstruction and detailed performance studies of both planar and curved silicon sensors. Beam tests were carried out using high-energy electron beams at the KEK
Photon Factory Advanced Ring (PF-AR). The
telescope system operated stably under realistic beam conditions, and its tracking performance was successfully validated. The bent ALPIDE sensor was operated at a bending radius of approximately 18 mm, consistent with ITS3's design goals, without any observable degradation in detection performance. The measured results confirm that the KATS provides a versatile and reliable platform for studies of curved MAPS technologies,
alignment precision, and tracking performance. These results provide important experimental validation of key technologies for future low-mass cylindrical silicon vertex detectors and establish KATS as a valuable facility for ongoing and future detector R&D.
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All authors Jiyoung Kim, Meike Danisch, Sungwoon Choi, Tatsuya Chujo, Taku Gunji, Yoonha Hong, Hangil Jang, Towa Katsuno, Ryotaro Kohara, MinJung Kweon, Sanghoon Lim, Inaba Motoi, Hikari Murakami, Hanseo Park, Jonghan Park, Shingo Sakai, Daito Shibata, Reita Wada, Kyungrim Woo, Yorito Yamaguchi, Seunghwan Yang, In-Kwon Yoo, Miljenko Suljic, Serhiy Senyukov, Giacomo Contin, Domenico Colella, Bong-Hwi Lim, Mihail-Bogdan Blidaru, Berkin Ulukutlu
High Energy Astrophysical Phenomena
Multi-Wavelength Identification of a Luminous Mid-Infrared Supernova Powered by Circumstellar Interaction with Binary-Driven Pre-supernova Mass Loss
Kohki Uno, Kishalay De, Geoffrey Mo et al. (+6 more)
Terminal mass-loss in massive
stars is commonly reconstructed from observations of circumstellar interaction in core-collapse
supernovae (CCSNe); however, such signatures can be easily missed depending on the phase when they appear. In this paper, we present a multi-wavelength study of SN\,2022yyz, a nearby CCSN selected by its luminous late-time mid-infrared (MIR) excess in NEOWISE at $> 500$ days after the discovery. Classified as a Type II SN at discovery, it reached a peak bolometric luminosity of $1.3^{+0.7}_{-0.4}\times10^{43}$ erg s$^{-1}$ before fading away with a light-curve drop at $\sim 300$ days. We present late-time HST/WFC3 ultraviolet (UV) imaging and Keck/LRIS spectroscopy at $\sim 1200$ days, which reveal clear signs of circumstellar-medium (CSM) interaction via a UV excess consistent with a strong MgII contribution and a flat-topped H$\alpha$ profile. We show that the bolometric light curve and the late-time UV luminosity can be explained using a semi-analytic CSM interaction model involving a broken power-law density profile: with $\sim 2.7~M_\odot$ of nearby, dense CSM within a radius of $\sim 10^{16}$ cm surrounded by wind-like outer CSM with a mass-loss rate of $\sim 10^{-4} {\rm ~M_\odot~yr}^{-1}$. The broken density profile indicates $\gtrsim 100\times$ mass-loss rate enhancement starting a few hundred years before explosion, pointing to a possible common-envelope ejection in a binary system. Despite being overlooked for follow-up at such proximity, our results demonstrate that IR photometric selection methods provide a powerful way of mapping terminal mass-loss in massive
stars - laying the groundwork for the Roman Space
Telescope surveys.
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All authors Kohki Uno, Kishalay De, Geoffrey Mo, Viraj Karambelkar, Kaitlyn Shin, Christoffer Fremling, Jesper Sollerman, Daichi Hiramatsu, Jacob E. Jencson
Statistical Mechanics
The Role of Concentration in Determining NaCl Nucleation Mechanism: A Story of Pathways Coexistence
Porhouy Minh and Sapna Sarupria
Deciphering the microscopic details of
crystal nucleation remains a key open problem in chemical physics. For aqueous sodium chloride (NaCl), the extent to which nucleation involves amorphous ion aggregation, and the supersaturation regime in which two-step-like behavior emerges, remains actively debated. In this work, we examine NaCl nucleation at 12, 13, and 14 mol/kg ($S = 3.2, 3.5, 3.8$) using unbiased path sampling with $\infty$RETIS. Through a combination of reaction coordinate analysis, joint and conditional probability distributions,
diffusion tensor analysis, and conditional free energy landscapes, we identify nucleation pathways without a priori mechanistic assumptions. While all concentrations are governed by the same reaction coordinate, indicating that
nucleus growth and structural ordering are central to crossing the barrier, the nature of reactive trajectories changes with supersaturation. At lower concentrations, nucleation mainly occurs via tightly coupled increases in cluster size and ordering, compatible with a one-step-like mechanism. As concentration increases, amorphous aggregation becomes increasingly decoupled from crystallization, and pathways involving substantial amorphous growth prior to crystallization become progressively more probable. Importantly, these pathways coexist within a single broad reaction channel rather than proceeding through distinct metastable intermediate states. Together, these results reconcile earlier, contradictory reports on NaCl nucleation mechanisms and support a view of nucleation as an ensemble of competing reactive pathways whose relative probabilities vary continuously with supersaturation. More broadly, our findings illustrate that substantial mechanistic diversity can emerge within a classical nucleation framework, without requiring distinct non-classical descriptions.
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Plasma Physics
All field strengths are possible locally in Boozer coordinates
Taylor J. Klotz, Nathan Duignan, Joshua W. Burby et al. (+1 more)
The
magnetic field strength is a central design object in the theory of
magnetic confinement of
plasma. Desirable confinement properties such as quasi-
symmetry and omnigenity are characterized by special forms of the field strength when it is given in the particular coordinate system called “Boozer coordinates." We ask a basic realizability question: which functions of Boozer coordinates can arise as the magnitude of a
magnetic field that is written in Boozer coordinates? Using exterior differential systems and the Cartan-Kähler
theorem, we show that every positive analytic function is locally realizable. Thus there is no local analytic obstruction to prescribing the field strength in Boozer coordinates; though further restrictions might arise from global
geometric or additional physical constraints.
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All authors Taylor J. Klotz, Nathan Duignan, Joshua W. Burby, James D. Meiss
Mesoscale and Nanoscale Physics
Intrinsic (valley) thermal Hall conductivity of phonons in graphene for integer quantum Hall phases
M. Selch
We calculate the intrinsic contribution to the (valley) thermal
Hall conductivity of
phonons in (Semenoff-gapped)
graphene in the
quantum Hall regime where bulk electron thermal transport is suppressed. The (valley) thermal
Hall transport of
phonons considered here originates from a
phonon (valley)
Hall viscosity induced by electron (valley)
Hall conductivity and viscosity via
geometric electron-
phonon coupling. The so generated
phonon (valley)
Hall viscosity is identified with the emergent (valley)
Hall viscosity recently introduced in Phys. Lett. A 595, 132096 (2026). While our calculations refer to
graphene, they may very well be generalized to other Dirac materials like group-VI transition metal dichalcogenides. We discuss the prospect of measuring the
phonon thermal
Hall conductivity in
graphene-based
heterostructures and estimate the corresponding valley response induced by electrons in the inversion
symmetry broken phase.
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