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Physics

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Monday 28 September

Instrumentation and Detectors

EXO-200 Public Data Release for AI/ML Applications

S. Al Kharusi, G. Anton, I. Badhrees et al. (+103 more)

We present a public release of a subset of calibration data from the EXO-200 experiment, a liquid xenon time projection chamber designed to search for neutrinoless double-beta decay in $^{136}$Xe. The released dataset consists of approximately one million events collected during $^{228}$Th calibration campaigns performed near the end of Phase-II operations between February 26 and March 2, 2018. For each event, the dataset includes raw detector waveforms from the U-wire, V-wire, and avalanche photodiode (APD) readout channels together with reconstructed event quantities including charge energy, light energy, rotated energy, and charge-cluster information. The dataset is distributed in HDF5 format and is intended to support data preservation, educational activities, and the development of modern machine-learning techniques for rare-event physics. This paper describes the detector, dataset contents, file structure, and public access mechanism.
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All authors S. Al Kharusi, G. Anton, I. Badhrees, P. S. Barbeau, V. Belov, T. Bhatta, M. Breidenbach, T. Brunner, G. F. Cao, W. R. Cen, C. Chambers, B. Cleveland, M. Coon, A. Craycraft, T. Daniels, L. Darroch, S. J. Daugherty, J. Davis, S. Delaquis, A. Der Mesrobian-Kabakian, R. DeVoe, A. Dolgolenko, M. J. Dolinski, J. Echevers, B. Eckert, W. Fairbank Jr., D. Fairbank, J. Farine, S. Feyzbakhsh, P. Fierlinger, Y. S. Fu, D. Fudenberg, P. Gautam, R. Gornea, G. Gratta, C. Hall, E. V. Hansen, J. Hoessl, P. Hufschmidt, M. Hughes, A. Iverson, A. Jamil, C. Jessiman, M. J. Jewell, A. Johnson, A. Karelin, L. J. Kaufman, T. Koffas, R. Krücken, A. Kuchenkov, K. S. Kumar, Y. Lan, A. Larson, B. G. Lenardo, D. S. Leonard, G. S. Li, S. Li, Z. Li, C. Licciardi, Y. H. Lin, R. MacLellan, T. McElroy, T. Michel, B. Mong, D. C. Moore, K. Murray, O. Njoya, O. Nusair, A. Odian, I. Ostrovskiy, H. Peltz Smalley, A. Perna, A. Piepke, A. Pocar, F. Retière, A. L. Robinson, P. C. Rowson, S. Schmidt, D. Sinclair, K. Skarpaas, A. K. Soma, V. Stekhanov, M. Tarka, S. Thibado, J. Todd, T. Tolba, T. I. Totev, R. Tsang, B. Veenstra, V. Veeraraghavan, P. Vogel, J.-L. Vuilleumier, M. Wagenpfeil, J. Watkins, M. Weber, L. J. Wen, U. Wichoski, G. Wrede, S. X. Wu, Q. Xia, H. Xu, D. R. Yahne, L. Yang, Y.-R. Yen, O. Ya. Zeldovich, T. Ziegler

Nuclear Theory

Nuclear scattering phase shifts with factorized geometric-time RODEO on a quantum processor

Myeong-Hwan Mun, Jubin Park, Myung-Ki Cheoun et al. (+1 more)

We reconstruct elastic $s$-wave neutron-proton ($np$) phase shifts from trapped spectra measured on IBM Aachen using a compressed RODEO circuit. For a schematic square-well interaction represented by classically constructed four-dimensional effective Hamiltonians, four positive-energy levels at five trap strengths supply twenty inputs to classical modified effective range expansion (MERE) extrapolation to free space. The six-cycle factorized geometric-time RODEO implementation (FG-R6) combines ancilla reuse, exact query-phase separation, post-compilation binding, and six numerically optimized geometric evolution times. Numerical cycle-count tests support this choice within the adopted local spectral tolerances. At the same three-qubit width and equal shot budgets, FG-R6 reduces median compiled depth and two-qubit-gate count by 33.1% and 37.2% relative to ten-cycle dynamic direct RODEO (direct R10), increases the median fitted amplitude, and lowers median finite-shot energy uncertainty from 0.610 to 0.534 keV. For this dataset's primary fit on the 0.1-30.0 MeV grid, the maximum central phase-shift deviation from exact-energy MERE decreases from $0.842^\circ$ to $0.163^\circ$, despite a larger root-mean-square (RMS) trapped-energy deviation. The full-grid gain arises mainly in the low-energy extrapolation region; direct R10 has slightly smaller residuals relative to the same reference on the 10.0-30.0 MeV common energy-interpolation subset. The FG-R6 central curve differs from the analytical square-well solution by at most $0.156^\circ$. Fit-form sensitivity remains appreciable and is assessed separately from finite-shot uncertainty. This reduced-space benchmark connects RODEO circuit compression to nuclear continuum observables and shows why circuit performance must be assessed through the scattering reconstruction and its energy range, not spectral RMS errors alone.
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All authors Myeong-Hwan Mun, Jubin Park, Myung-Ki Cheoun, Eunja Ha

Quantum Physics

Optimal Quantum Algorithms for Ordered Search

Joseph Carolan and Andrew M. Childs

Ordered search is the problem of locating a target element in a sorted list of size $n$ using comparison queries. Classically, binary search requires $\lceil \log_2 n\rceil$ queries, which is optimal. Quantum algorithms offer a constant-factor speedup, but the precise constant has been a longstanding open question. We close this gap by exhibiting two new quantum algorithms for ordered search, each using the optimal $\frac{1}{\pi}\ln n+o(\log n)$ queries. The first, discovered by Claude Fable 5, is a simple zero-error algorithm derived from a continuum relaxation of the problem. The second, discovered by GPT-5.6-Sol (informed by Claude's zero-error algorithm), is an exact algorithm based on an analytic solution of the polynomial program of Farhi, Goldstone, Gutmann, and Sipser.
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Disordered Systems and Neural Networks

Pre-registered tests of solid-state-physics-inspired LLM compression: a cluster-level negative result at small-language-model scale

Jun-qiang Lu

We report a three-month autonomous research-agent program testing five solid-state-physics-inspired compression mappings on pretrained language models, with predictions committed to git before any pilot data and a 3-sigma gate deciding PASS or SHELVE. The common anchor – area-law / Kohn-nearsighted decay of the one-particle density matrix – has a distance face (P001 Wannier, P002 tight-binding) and a rank face (P003 DMRG-truncated MLPs, P005 Wilson-RG, P011 tensor-train embeddings). P005 was pre-empted at Phase 1; three of four Phase-3 pilots were falsified. On the attention face, GPT-2-medium attention-versus-distance is best fit by a stretched exponential in 12 of 16 median-layer heads once probe padding is excluded, and a tight-binding cutoff costs +96% perplexity (P002); on Pythia-160M the Wannier sparsity 0.054 +/- 0.004 is indistinguishable from PCA, random-Haar and identity baselines (P001). On the rank face, per-token tensor-train bond dimension does not track surprisal (r = 0.016 vs a pre-registered 0.65) and the format inflates rather than compresses (P011). P003 is mixed: its scaling claim shelved (r = -0.434), its MPO premise died at stage-0, and its cross-paper check, r = 0.523 as first written, collapses to 0.047 under the same correction, leaving both cross-paper checks null. The results invert the pre-registered prediction that most attention heads behave like Kohn-nearsighted insulators, pointing instead to critical, glassy or heavy-tailed regimes; the inversion is specific to the <= 350M scale tested, while the rank-face no-gain result held to 7-8B. We contribute the pre-registration + 3-sigma + cluster-framing + append-only-catalogue discipline – including why our own enforcement gate was designed but not deployed – four pre-registered negative results with full data release, and the inversion. The catalogue holds eighteen concluded studies, seventeen negative.
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Quantum Physics

A threshold for maximal Schmidt number from spectrum

Junhyeong An and Soojoon Lee

The Schmidt number quantifies the dimensionality of entanglement in bipartite quantum states. We investigate when the spectrum of a state on $\mathbb{C}^d \otimes \mathbb{C}^d$ alone guarantees that its Schmidt number is not maximal. By deriving spectral bounds for $(d-1)$-block positive operators, we prove that $\mathrm{LS}_p\subseteq \mathrm{ASN}_{d-1}$ for $p\leq \lfloor d^2/2\rfloor$, where $\mathrm{LS}_p$ denotes the set of states whose largest eigenvalue does not exceed the sum of their $p$ smallest eigenvalues, and $\mathrm{ASN}_{d-1}$ denotes the set of states whose Schmidt number remains at most $d-1$ under all global unitaries. This also yields a simple sufficient condition involving only the largest eigenvalue. As an application, we show that states satisfying the reduction criterion under arbitrary global unitaries belong to $\mathrm{ASN}_{d-1}$ in every dimension. This subsumes the earlier result that absolutely positive partial transpose states belong to $\mathrm{ASN}_{d-1}$. The global unitary requirement is nevertheless essential: for every $d\geq3$, we construct states of maximal Schmidt number satisfying the reduction criterion on both subsystems.
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High Energy Physics (Theory)

RG Limit Cycles in BKT Flows $\equiv$ Periodic Real-Time Dynamics in the Current-Current Perturbed $SU(2)_1$ WZW Model

Parameshwar R. Pasnoori

We establish an exact correspondence between renormalization-group (RG) evolution and real-time quantum dynamics in the anisotropic current-current perturbed $SU(2)_1$ Wess-Zumino-Witten (WZW) model. Using its integrable fermionic representation, we construct the exact time-dependent many-body wavefunction by means of the generalized Bethe ansatz and show that periodic boundary conditions lead to quantum Knizhnik-Zamolodchikov equations associated with the XXZ trigonometric $R$-matrix, which corresponds to the quantum affine algebra $\mathcal{U}_q(\widehat{\mathfrak{sl}_2})$ evaluated in its spin-$1/2$ evaluation representation. Consistency of these equations constrains the temporal evolution of the longitudinal and transverse interaction strengths. In the universal regime, these integrability conditions are exactly equivalent to the Berezinskii-Kosterlitz-Thouless RG flow equations upon identifying physical time with the logarithmic RG scale. Consequently, the RG limit cycles of the anisotropic current-current perturbed $SU(2)_1$ WZW model are realized as periodic real-time evolution of its interaction strengths. Our results provide an exact dynamical realization of RG limit cycles and establish a direct connection between cyclic RG flows, quantum integrability, and periodically driven interacting quantum field theories.
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Cosmology and Nongalactic Astrophysics

Reconstructing the evolution of deceleration parameter with the Lagrange interpolation method

Kaituo Zhang, Bing Xu, Hongwei Yu et al. (+1 more)

In this paper, we reconstruct the evolution of the deceleration parameter using cubic and quartic Lagrange interpolation methods, based on the latest observational data. This data includes baryon acoustic oscillation (BAO) measurements from DESI, cosmic microwave background (CMB) distance priors from Planck 2018, and three datasets of type Ia supernovae (SNe Ia): DES-Dovekie, Pantheon+, and Union3. To mitigate the impact of the nonuniform distribution of data in redshift, we carry out the reconstruction not only in the standard redshift $z$ but also in the $y$-redshift $y\equiv z/(1+z)$ and the log-redshift $\zeta\equiv\ln(1+z)$. The cubic and quartic reconstructions of $q(z)$ from the DESI BAO+CMB+SNe Ia datasets indicate a clear deviation from the $\Lambda$CDM model at low redshift ($z<0.3$), supporting a weaker present-day cosmic acceleration than the predictions of the $\Lambda$CDM model. The reconstructed $q(z)$ exhibits an overall oscillatory pattern around the $\Lambda$CDM model throughout its evolution. Only the cubic-$y$ and cubic-$\zeta$ reconstructions with the DESI BAO+CMB+Union3 data provide evidence that the cosmic acceleration appears to have already reached its maximum value and is beginning to slow down. However, when incorporating the measurement of the Hubble constant $H_0$ from the Supernovae and $H_0$ for the Equation of State (SH0ES) Collaboration, the evolution of $q(z)$ from cubic reconstructions shifts toward the $\Lambda$CDM prediction. Regardless of the presence or absence of the $H_0$ prior, all reconstructions imply that the deceleration-acceleration transition occurred earlier than predicted by the $\Lambda$CDM model. Nevertheless, the Bayesian evidence still favors $\Lambda$CDM, while the frequentist analysis indicates a $>2\sigma$ preference for the Lagrange-interpolation reconstructions, hinting at the existence of dynamical dark energy.
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All authors Kaituo Zhang, Bing Xu, Hongwei Yu, Puxun Wu

High Energy Physics (Phenomenology)

Freeze-in of anapole and charge-radius inelastic dark matter: X-ray probes of a decoupled vector portal

Krzysztof Jodłowski and Chih-Ting Lu

We study freeze-in production and experimental probes of inelastic dark matter (iDM) coupled to the Standard Model through dimension-6 transition anapole and charge-radius operators. These interactions arise upon integrating out the heavy dark photon of a broken $U(1)_D$ vector portal. We focus on mass splittings below the dielectron threshold, where the excited-state decay is cosmologically long-lived and decays predominantly through $\chi_1\to\chi_0+3\gamma$, producing a distinctive keV–MeV photon spectrum. We calculate the decay rate and photon spectrum analytically in the Euler–Heisenberg limit and evaluate finite-electron-mass corrections using the full one-loop amplitude. We then combine X-ray limits with freeze-in relic density targets and complementary direct detection (DD) and accelerator constraints. The surviving $\chi_1$ population also leads to exothermic downscattering signatures at DD experiments, including the possibility of explaining the LZ signal, while the three-photon decay is constrained by X-ray data. At $\Delta=900\,\mathrm{keV}$, INTEGRAL/SPI probes the Boltzmann-suppressed high-mass branches of the freeze-in targets, whereas the NuSTAR limits at $\Delta=100\,\mathrm{keV}$ are substantially weaker because of the steep splitting dependence of the decay width. Our results demonstrate the potential of X-ray observations as a probe of freeze-in through a decoupled vector portal and of the reheating temperature governing the iDM production.
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Atmospheric and Oceanic Physics

Low latency global carbon budget reveals strong land sink recovery in 2025

Philippe Ciais, Piyu Ke, Xiangjun Tian et al. (+32 more)

The atmospheric CO2 growth rate fell sharply in 2025, from a record 3.76 $\pm$ 0.09 ppm yr-1 in 2024 to 2.06 $\pm$ 0.09 ppm yr-1 (NOAA marine boundary layer observations), below the 2015-2022 mean of 2.47 ppm yr-1, even as fossil CO2 emissions rose by 0.7% to 10.38 GtC yr-1. Here we present a low-latency global and regional carbon budget for 2025, combining three dynamic global vegetation models (DGVMs) and ocean model emulators with four atmospheric inversions constrained by OCO-2 satellite retrievals. The global net land sink reached 2.36 $\pm$ 0.16 GtC yr-1 in 2025 (DGVMs: 2.04 $\pm$ 0.24; inversions: 2.68 $\pm$ 0.20 GtC yr-1), strengthening by 2.81 $\pm$ 0.31 GtC yr-1 from 2024 and exceeding the 2015-2022 mean by 0.71 $\pm$ 0.13 GtC yr-1. Ocean uptake (3.11 $\pm$ 0.36 GtC yr-1) remained similar to 2024, making the land sink rebound the dominant driver of the slowdown in CO2 growth. Tropical lands shifted from net sources in 2024 to net sinks in 2025, with enhanced uptake across much of Africa and northern Eurasia, and land flux anomalies covaried with GRACE terrestrial water storage. Where the sink had weakened substantially in 2023-2024, about 80% of the area showed some recovery, with overall recovery of 87.3% (DGVMs) to 99.5% (inversions). Recovery exceeded 100% in the tropics but remained incomplete in the northern extratropics, indicating a strong but spatially uneven rebound of the land carbon sink.
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All authors Philippe Ciais, Piyu Ke, Xiangjun Tian, Stephen Sitch, Wei Li, Xiaomeng Du, Xiaofan Gui, Ben Poulter, Thomas Colligan, Auke M. van der Woude, Anne-Wil van den Berg, Wouter Peters, Zhu Liu, Zhu Deng, Zhe Jin, Yilong Wang, Junjie Liu, Sudhanshu Pandey, Chris O'Dell, Jiang Bian, John Miller, Xin Lan, Jefferson Goncalves De Souza, Michael O'Sullivan, Pierre Friedlingstein, Youngryel Ryu, Helin Zhang, Julien Alléon, Yi Xi, Daniel S. Goll, Lei Zhu, Guido R. van der Werf, Yitong Yao, Shilong Piao, Frédéric Chevallier

Optics

Surface-Normal Electric Spin in Obliquely Excited Parallel-Slit SPP Fields

Naoki Ichiji

Handedness-dependent light-matter interactions require control of local electric-field rotation, but generating controlled surface-normal spin textures is difficult under oblique illumination. Here, we show that oblique s-polarized illumination of a periodic array of parallel slits produces spatially alternating surface-normal electric spin, with its period tunable by the incidence angle. We further show that the spin texture changes qualitatively between substrate- and air-side excitation depending on whether the SPP field interferes with the excitation field. Under substrate-side excitation, the spin distribution follows the conventional spin-flow relation, whereas under air-side excitation, interference between the SPP and excitation fields produces a distinct spatial periodicity and allows the spin extrema to coincide with the field-intensity maxima. A simple interference model reproduces these contrasting spin textures.
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Astrophysics of Galaxies

Trigonometric Parallaxes of Maser Sources toward the Far Side of the Milky Way

Z. H. Lin, Y. Xu, M. Reid et al. (+2 more)

We present trigonometric parallaxes and proper motions for eight maser sources associated with high-mass star-forming regions. Four 22 GHz H$_2$O masers and four 6.7 GHz CH$_3$OH masers were observed over eight epochs between 2024 and 2025. Combining parallax, proper-motion, and radial-velocity information, we determine distances and spiral-arm assignments for these sources. The newly measured far-side masers extend the known distributions of the Sagittarius and Perseus arms toward Galactic longitudes as small as $\ell\sim10^\circ$. Their locations and kinematics agree well with recently updated spiral-arm models based on maser astrometry. In particular, the new measurements show that the far-side Sagittarius and Perseus arms tend to converge toward a common spiral feature in the inner Galaxy. This configuration is consistent with the bifurcation scenario proposed for the Milky Way spiral structure, although an unresolved inter-arm structure provides an alternative interpretation that cannot yet be excluded.
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All authors Z. H. Lin, Y. Xu, M. Reid, J. J. Li, S. B. Bian

Quantum Physics

Monotonicity of the Rényi channel capacity under non-signaling assisted channel simulation

Tina Shariat, Matt Hoogsteder-Riera and Marco Tomamichel

We give an alternative variational proof that non-signaling correlations shared between the sender and receiver cannot increase the Rényi capacity of a classical channel. This monotonicity follows from the data-processing inequality for channel divergences established by Oufkir, Yao and Berta. Our approach works directly with the information-radius representation of the capacity. The constraints defining non-signaling boxes are linear in the box, while the Rényi capacity depends on the channel nonlinearly. We use a Legendre transform to express the capacity as an extremum over a family of affine functionals in which the channel appears linearly. Combining this method with separate arguments for the Shannon capacity and endpoint orders, we recover monotonicity at every order from zero to infinity. We then derive consequences for standard coding exponent functions: non-signaling simulation cannot increase the random-coding or sphere-packing exponent below capacity, or decrease the strong-converse exponent above capacity.
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Astrophysics of Galaxies

Large-Scale Spiral Structure of the Milky Way Traced by Young Classical Cepheids

Z. H. Lin, C. J. Hao, D. J. Liu et al. (+5 more)

Using 985 classical Cepheids younger than 100 Myr, we investigate the large-scale spiral structure of the Milky Way by comparing their spatial and kinematic distributions with the R19 (four-arm) and X23 (multiple-arm) spiral-arm models. Both models provide reasonably good descriptions of the current sample: R19 yields slightly smaller point-to-arm distances, whereas X23 has a higher supported-arm fraction, but the descriptive statistics do not provide a decisive preference between them. Model-dependent arm assignment and refitting suggest that the distribution of the youngest Classical Cepheids (20–60 Myr) is consistent with an X23-like multiple-arm in which the Perseus and Norma arms form two dominant inner arms extending toward the ends of the Galactic bar, the Sagittarius and Centaurus segments are possible branches of these inner arms, and Local, Outer, and other features constitute additional arm segments. The updated model improves the constraints on the southern spiral structure, yielding smaller point-to-arm distances and a higher supported-arm fraction. Some of these structures extend to heliocentric distances of approximately 15~kpc.
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All authors Z. H. Lin, C. J. Hao, D. J. Liu, Y. J. Li, J. J. Li, Y. W. Dong, Y. X. He, Jarken Esimbek

Quantum Physics

Quantum memory in an effective $\Lambda$-type system using dynamic detuning control of a superconducting qubit pair

Hsin Chang, Kai-I Chu, Ite A. Yu et al. (+2 more)

We theoretically investigate quantum-light storage in an effective $\Lambda$-type system formed by a pair of tunable superconducting qubits coupled to a semi-infinite transmission line and separated by half a wavelength. The frequency detuning between the qubits directly couples the superradiant excited state and the subradiant metastable state. By adjusting the qubit detuning, the system exhibits a controllable spectral response accompanied by slow-light behavior. Dynamically controlling the detuning enables an incident quantum field to be mapped onto the subradiant collective state, stored as a long-lived excitation, and subsequently retrieved on demand. Our results establish the proposed system as a minimal and tunable quantum-memory architecture for scalable superconducting quantum networks.
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All authors Hsin Chang, Kai-I Chu, Ite A. Yu, Yen-Hsiang Lin, Yung-Fu Chen

Quantum Physics

Nakayama's reduction of quantum topos and Bayesian quantum computing

Atsuhide Mori

Nakayama found the way to limit the contexts in the Döring-Isham topos quantum theory and unified such limitation and the definition of probability as a single choice of topology. We explain how this unification supports the Bayesian perspective where the probability changes as data is obtained. We describe this change as a local shift of the applicability of a predictive theory and apply it to quantum computing.
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Chemical Physics

Machine-learned Laplacian-level density functional from exact exchange-correlation potentials and energies

Arghadwip Paul, Bikash Kanungo, Sambit Das et al. (+1 more)

We present NNLap, a machine-learned Laplacian-level exchange-correlation (XC) functional that augments PBE with a neural-network correction depending on the electron density, its gradient, and its Laplacian. The model is trained on exact XC potentials and energies, obtained through inverse density-functional theory (DFT) calculations on configuration-interaction densities. Despite training on only a few systems – five atoms and three molecules – the model achieves remarkable accuracy on thermochemistry benchmarks, competing with the meta-GGA functionals SCAN and r2SCAN. It also attains accurate total energies, comparable to SCAN and better than r2SCAN and B3LYP. This shows that a Laplacian-level model, trained on exact XC potentials and energies, can reach the accuracy of meta-GGAs without their orbital dependence.
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All authors Arghadwip Paul, Bikash Kanungo, Sambit Das, Vikram Gavini

Astrophysics of Galaxies

Morphological Statistic of Milky Way-like Galaxies

Zehao Lin, Junye Wei, Ye Xu et al. (+5 more)

We analyze the spiral morphology of 1,738 nearby galaxies with similar Hubble type of the Milky Way ($i<60^\circ$, $z<0.048$) using multi-band optical images from the Sloan Digital Sky Survey and Digitized Sky Survey. Multiple-arm systems dominate, comprising $\sim$50-60% of the sample and $\sim$75% of large galaxies ($d_{\rm max} \geqslant 18~\mathrm{kpc}$). In $90\pm3$% of multiple-arm galaxies, two inner arms extend into multiple outer arms; three-arm inner structures occur in $9\pm2$%, and four or more are rare ($<1$%). Morphology and inner-arm counts are consistent across bands at $\sim$80%. Bifurcation points, marking the transition from two inner arms to multiple outer arms, occur in up to $\sim$40% of galaxies, are more prominent in bluer bands tracing younger stellar populations, and cluster within 4-7~kpc of galaxy centers. These statistics suggest that the Milky Way's inner two-arm and outer multiple-arm morphology, including bifurcations at similar radii, is broadly consistent with that of a typical multiple-arm spiral galaxy.
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All authors Zehao Lin, Junye Wei, Ye Xu, Yingjie Li, Chaojie Hao, Dejian Liu, Yiwei Dong, Zhen-yu Wu

Optics

Monolithically integrated photonic neural network at driven-dissipative criticality

Yuming Zhang, Ruoran Wang, Jingcheng Li et al. (+4 more)

Artificial intelligence increasingly demands computing architectures capable of adaptive representation, temporal information processing, and robust operation under uncertainty. However, conventional photonic neural architectures typically rely on predefined computational operations and separate functional modules, limiting the ability of physical systems to exploit their intrinsic dynamics for intelligence. Here, we demonstrate a monolithically integrated active photonic neural network (APNN) that harnesses driven-dissipative criticality as a physical computational resource. By balancing optical excitation and dissipation, the system operates near a critical regime where weak input-dependent variations are amplified into separable representations while stable attractor dynamics are preserved. The APNN integrates an optoelectronic nonlinear array and a reconfigurable symmetric optical coupling matrix on a silicon photonic chip, enabling recurrent physical computation within a compact closed loop. We demonstrate nonlinear classification with 95.2% accuracy using only 100 training samples and 44 trainable parameters. And it remains robust at an ultralow signal-to-noise ratio of -30 dB. Beyond static recognition, the same driven-dissipative dynamics enable long-range temporal feature extraction from electrocardiogram signals and associative recovery of corrupted patterns through attractor-based relaxation. These results establish driven-dissipative criticality as a unified mechanism for representation enhancement, temporal information retention, and error-resilient computation, providing a pathway toward scalable photonic systems in which intelligence emerges from intrinsic physical dynamics.
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All authors Yuming Zhang, Ruoran Wang, Jingcheng Li, Hailong Zhou, Jianji Dong, Zhipei Sun, Xinliang Zhang

Chemical Physics

Basis Functions for Time-Dependent Kohn-Sham Inversion

Paul M. Zimmerman, Joshua Kammeraad, Duy-Khoi Dang et al. (+1 more)

Floquet theory provides insight into the inversion of time-dependent Kohn-Sham density functional theory. Specifically, mathematical derivations show that the fundamental frequencies of a time-dependent wavefunction solution are the leading-order harmonics for the TD-KS state. Numerical tests of the resulting ansatz in 1D and 3D for atomic and molecular cases demonstrate its utility. In particular, low $L_{2}$ errors in the time-dependent density and longitudinal current were found, even though currents were not an explicit optimization objective. In all, the proposed inversion ansatz provides exchange-correlation potentials from time-dependent wavefunctions, is highly interpretable, and may significantly help in the development of nonadiabatic density functionals.
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All authors Paul M. Zimmerman, Joshua Kammeraad, Duy-Khoi Dang, Harish S. Bhat

High Energy Astrophysical Phenomena

Comment on "Fermi-LAT Galactic Center Excess Morphology of Dark Matter in Simulations of the Milky Way Galaxy"

Kevork N. Abazajian, Jason Kumar and Oscar Macias

Muru et al. [Phys. Rev. Lett. 135, 161005 (2025)] conclude from the HESTIA constrained simulations that the $\gamma$-ray morphologies of the Galactic Center Excess predicted by dark matter annihilation and by an old stellar population are essentially indistinguishable. Their "quadratic dark matter" maps, however, show the square of the mass projected along the line of sight, $\bigl[\int\rho\,s^{2}\,ds\bigr]^{2}$, rather than the annihilation integral $\int\rho^{2}\,ds$. Squaring a nonnegative map preserves its isophote shapes at corresponding intensity levels, as confirmed by the reported contour axis ratios. The corrected calculation on the same simulations does not support their conclusion.
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Astrophysics of Galaxies

PEGASUS (Pfs Emission-line GAlaxy SUrvey with Subaru): II. Metal Poor AGNs in High Equivalent-Width Narrow-Band Emitters

Hisakazu Uchiyama, Tohru Nagao, Mariko Kubo et al. (+19 more)

We present Subaru 'Ōnohi'ula Prime Focus Spectrograph (PFS) optical–NIR spectroscopic follow-up of high-equivalent-width (EW) narrow-band (NB) emission-line galaxies selected from Hyper Suprime-Cam Subaru Strategic Program, to assess whether high-EW sources preferentially host low-metallicity AGNs. PFS spectroscopy yielded secure identifications for 583 targets, including 581 sources with reliable PFS redshift solutions and two manually identified $z\sim4$ interlopers. We construct BPT diagnostics for the 70 objects with significant detections in all four BPT lines. Among them, $\sim34\%$ are located in the AGN region of the BPT diagram, suggesting that AGNs constitute a significant fraction of the sample. A non-negligible fraction does not populate the classical AGN branch; instead, it lies in the intermediate “valley” between the star-forming and AGN sequences. Comparison to Cloudy models suggests that the valley population is consistent with sub-solar metallicities. Three He II/[Ne V]-detected sources are also found in the star-forming region of the BPT diagram and extend to lower-metallicity solutions, consistent with $Z/Z_{\odot}\approx0.25-0.5$ ($12+\log({\rm O/H})\approx8.1-8.4$). One object shows a clear broad H$\alpha$ component; a multi-component fit yields $M_{\rm BH}\approx8.8\times10^{6} M_{\odot}$ and $\lambda_{\rm Edd}\approx0.035$, consistent with near-solar narrow-line region metallicity. The fraction of point-like sources in the parent target sample ($22\%\pm2\%$) is intermediate between those of star-forming galaxies ($12\%\pm5\%$) and AGN ($33\%\pm10\%$), consistent with a contribution from compact components. Stacked [O III] line profiles show no clear evidence for strong outflows. Our findings suggest that high-EW NB selection efficiently identifies candidates for metal-poor AGNs.
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All authors Hisakazu Uchiyama, Tohru Nagao, Mariko Kubo, Tadayuki Kodama, Rhythm Shimakawa, Akio Inoue, Masayuki Tanaka, Jialai Wang, Ronaldo Laishram, Yuma Sugahara, Masato Onodera, Kazuki Daikuhara, Ko Ishida, Ryo Albert Sutanto, Haruka Kusakabe, Yoshiki Matsuoka, Alberto Rodriguez-Ardila, Yuta Suzuki, Yoshiki Toba, Xinfeng Xu, Yongquan Xue, Yongming Liang

Materials Science

Finite-temperature grain boundary phases, transformations, and diagrams in alloys

Flynn Walsh and Timofey Frolov

Current understanding of alloy grain boundaries is limited by the incompleteness of atomistic simulation techniques, which either neglect entropy or artificially constrain the atomic density. This study introduces Monte Carlo simulations that simultaneously sample all the microscopic degrees of freedom in complex interfaces: position, configuration, and atom number. The method enables rigorous predictions of finite-temperature grain boundary structures, phase transformations, and diagrams in multicomponent materials. Simulations of W-V alloys demonstrate the necessity of the approach by uncovering a range of previously inaccessible phase transitions including condensation of interstitial solutes and transformation of dislocation structure.
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Strongly Correlated Electrons

Bogoliubov coupled-cluster theory for su(2) Hamiltonians

Swarnamoy Ghosh, Thomas M. Henderson and Gustavo E. Scuseria

Coupled-cluster theory is the method of choice for weakly correlated systems, but in strongly correlated systems where the mean-field reference is qualitatively poor, it can break down badly. These failures can be ameliorated by using symmetry-broken mean-field references. For systems that spontaneously break spin symmetry, we might favor an unrestricted reference. In systems that instead break number symmetry, we turn to Bogoliubov coupled cluster theory. In this work, we apply Bogoliubov coupled-cluster to Hamiltonians with an underlying su(2) algebra to study the pairing Hamiltonian and the spin XXZ and J1-J2 models by exploiting the correspondence between fermionic-pair operators and spin-1/2 operators. For the pairing problem, the reference is the usual Bardeen–Cooper–Schrieffer (BCS) quasiparticle vacuum, while for spin systems we use the analogous spin-BCS reference, which breaks Sz symmetry and provides a flexible starting point for strongly correlated regimes. Correlation is incorporated through a hierarchy of coupled-cluster approximations. Beyond energies, we compute the response density matrices for the evaluation of spin–spin correlation functions for the XXZ and J1-J2 Heisenberg models, and the pairing parameter and particle-number variance for the pairing Hamiltonian. We also derive the corresponding relaxed density matrices, including the effects of orbital relaxation. Benchmark calculations for the half-filled pairing Hamiltonian and spin models demonstrate that Bogoliubov coupled cluster provides a systematically improvable wave-function-based approach for su(2) Hamiltonians, including geometrically frustrated spin systems requiring complex and noncollinear BCS references.
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Mathematical Physics

The equivalence of topological indices for $\mathrm{U}(1)\rtimes\mathbb{Z}_2$-symmetric quantum spin chains

Hal Tasaki

Symmetry-protected topological (SPT) phases in quantum spin chains are distinguished by topological indices. Ogata's operator-algebraic indices apply to a broad range of symmetry classes without requiring continuous symmetry, whereas the elementary twist index of Tasaki requires $\mathrm{U}(1)$ symmetry. We prove their equivalence in the common setting of integer-spin chains with on-site $\mathrm{U}(1)\rtimes\mathbb{Z}_2$ symmetry and a symmetric locally-unique gapped ground state, without assuming translation invariance or a matrix product representation. A charge-fluctuation estimate yields a strong-limit construction of half-chain rotations with their phases fixed. An exact group commutator identity then identifies the Ogata index with the limit of local twist expectations and gives an explicit error bound. This provides a computable formula for the index when a lower bound on the gap and the relevant ground-state expectations are available. Combining the equivalence with a recent boundary-field gap theorem of OpenAI and our earlier twist-index calculation, we obtain a spin-rotation-invariant locally-unique gapped ground state of the infinite $S=1$ antiferromagnetic Heisenberg chain with both indices equal to $-1$, without assuming infinite-volume uniqueness. The author formulated the problem and proposed the basic strategy, while ChatGPT Astra made substantial contributions to the development of the proof.
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Earth and Planetary Astrophysics

A JWST Study of Stardust. II. Polycyclic Aromatic Hydrocarbons in Comet 81P/Wild 2 and Implications for Primitive Solar System Carbon

Nathan X. Roth, Stefanie N. Milam, Diane H. Wooden et al. (+11 more)

We report observations of comet 81P/Wild 2, target of the Stardust sample return mission, on UT 2023 March 20 and 24 at a heliocentric distance ($r_H$) of 1.85 au using the NIRSpec and MIRI integral field unit spectrographs on board the James Webb Space Telescope (JWST). This study is the first compositional comparison between JWST remote-sensing spectroscopy of a solar system object against terrestrial analysis of its returned samples. Recent work determined contributions of molecular emission from coma volatiles and thermal emission from the nucleus and coma dust grains to these spectra. Subtracting the molecular and thermal emission models produces a residual spectrum with a clear resonance near 3.37 $\mu$m and multiple others spanning the $6 - 12$ $\mu$m region. Analysis of these residuals provides strong evidence for the presence of polycyclic aromatic hydrocarbons (PAHs) in the coma of 81P/Wild 2. The resulting PAH populations reflect material incorporated into the nucleus of 81P/Wild 2 that was inherited from the diffuse interstellar medium, the interstellar medium, and the protoplanetary disk. The PAHs sensed by JWST are compared to those detected in laboratory analyses of the Stardust mission returned samples.
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All authors Nathan X. Roth, Stefanie N. Milam, Diane H. Wooden, Els Peeters, Charles E. Woodward, Dominique Bockelee-Morvan, Michael S. P. Kelley, Steven B. Charnley, Simon J. Clemett, Martin A. Cordiner, Perry A. Gerakines, David E. Harker, Ella Sciamma-O'Brien, Geronimo L. Villanueva

Disordered Systems and Neural Networks · Cross-listed from cs.LG

Evolution of fairness in multi-objective reinforcement learning framework

Jingyi Zhang, Xin Ou, Guozhong Zheng et al. (+3 more)

Fairness, as a fundamental social norm, continues to pose a longstanding puzzle regarding its emergence. Traditional game-theoretic models largely rely on the assumption of Homo economicus, wherein individuals are purely rational and self-interested, acting solely to maximize material payoffs. Such accounts, however, overlook the multidimensional nature of human decision-making, which is often shaped also by other considerations beyond economic incentives. To address this gap, we propose a multi-objective reinforcement learning framework that models the evolution of fairness as a dynamic trade-off between material payoff maximization and fairness-driven moral behavior, regulated by a fairness pressure coefficient. Using simulations of a two-objective Q-learning ultimatum game, we find that increased fairness pressure promotes fair outcomes, as expected. Strikingly, however, under moderate pressure, responder behavior reverses: responders become “forgiving" by accepting low offers – a pattern in line with our daily experience. Microscopic analyses reveal that this strategy reversal stems from competition between payoff-maximizing and fairness-oriented preferences. We further extend our framework to an asymmetric setting, where proposers and responders assign different weights to the two objectives. Overall, our work expands the reinforcement learning paradigm from a single-objective to a multi-objective formulation, offering a versatile tool for elucidating a broader range of human social behaviors.
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All authors Jingyi Zhang, Xin Ou, Guozhong Zheng, Shengfeng Deng, Jiqiang Zhang, Li Chen

Earth and Planetary Astrophysics

Dynamical Impacts of Accretion Streamers on Protoplanetary Disks

Han-Gyeol Yun, Jeong-Eun Lee, Jaehan Bae et al. (+1 more)

Recent observations suggest that accretion streamers are common in protoplanetary disks, yet their dynamical impact on disk evolution remains poorly understood. Using three-dimensional hydrodynamic simulations with mass infall rates of $10^{-8}$–$10^{-6} \ M_{\odot}\ \mathrm{yr}^{-1}$, we investigate how streamer accretion influences the structure and evolution of protoplanetary disks. We find that a prograde streamer can excite disk eccentricity globally to values as high as $\sim0.4$. The resulting eccentric disk develops prominent spiral arms and crescent-shaped overdensities whose spatial structures agree remarkably well with analytic eccentric-disk theory. It also undergoes significant warping, and exhibits enhanced and variable stellar accretion. In contrast, retrograde streamer accretion efficiently removes disk angular momentum, producing a compact disk and, in extreme cases, triggering disk breaking. Using synthetic ALMA molecular-line observations, we show that streamer-driven perturbations generate observable kinematic signatures, including Doppler flips in moment maps and wiggles in position–velocity diagrams. Remarkably, these signatures can persist for up to $100\ \mathrm{kyr}$ after infall has ceased, suggesting that some kinematic disturbances observed in disks without currently detected streamers may be relics of past infall events. Finally, we discuss the implications of streamer-driven disk evolution for planet formation and planet–disk interactions.
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All authors Han-Gyeol Yun, Jeong-Eun Lee, Jaehan Bae, Woong-Tae Kim

Optics

Stimulated Electro-optic Scattering

Violet Workman and Gaurav Bahl

Stimulated Brillouin Scattering (SBS) couples light to acoustic waves and underpins applications ranging from sensing and signal processing to quantum photonics. In solids, this interaction is generally attributed to photoelasticity and the motion of dielectric boundaries. Here we show that piezoelectricity opens an additional, previously unrecognized pathway that can substantially reshape Brillouin gain. This contribution arises from the combined action of linear electro-optic “Pockels” scattering and its reciprocal $\chi^{(2)}$-mediated optical drive, which couple optical fields to the electric fields that accompany mechanical motion in piezoelectrics. We formally incorporate these effects into the modern theory of SBS and apply it to monolithic lithium niobate waveguides. In addition to large enhancement and suppression of the Brillouin gain, we surprisingly find occurrences of large gain where conventional theory would otherwise have predicted zero Brillouin interaction. These instances are the first identification of purely electro-optic SBS, a process we term stimulated electro-optic scattering, as it only involves interactions between electromagnetic fields even though a mechanical excitation is present. Our results establish the electro-optic tensor as a key governing parameter for Brillouin interactions in piezoelectric media and provide a new degree of freedom for engineering photon-phonon coupling independent of photoelasticity and index contrast.
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Mesoscale and Nanoscale Physics

(Sub)nanoscale Visualization of Reconstruction-Driven Moiré Exciton Localization and Delocalization

Medha Dandu, Sriram Sankar, Giovanny Espitia et al. (+12 more)

Spectral fingerprints in optical absorption and emission have typically been used as a signature of exciton localization in twisted moiré bilayers. However, the mechanism by which excitons become confined to specific stacking sites and their associated optical signature is experimentally unresolved. Here, we directly visualize in real space how tuning the change in extent of structural reconstruction leads to localization and delocalization of moiré excitons in the WSe2/WS2 moiré superlattice. Using cryogenic monochromated electron energy loss spectroscopy, together with first-principles GW-Bethe Salpeter equation calculations and optical spectroscopy, we uncover the physical mechanism that drives the correlation between twist-angle-dependent structural transformations, the real-space localization of moiré excitons, and their optical signatures. Surprisingly, and in contrast to the prevailing understanding, we show that the emergence of new moiré exciton resonances in the optical spectra alone is insufficient to establish exciton localization. Instead, the extent of structural reconstruction and external strain drives exciton localization, leading to new design principles for engineering moiré excitons and strain-aware quantum optoelectronic devices.
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All authors Medha Dandu, Sriram Sankar, Giovanny Espitia, Rwik Dutta, Patrick J. Hays, Daria Blach, Takashi Taniguchi, Kenji Watanabe, James R. Chelikowsky, Seth Ariel Tongay, Peter Ercius, Jordan A. Hachtel, Mit H. Naik, Archana Raja, Sandhya Susarla

High Energy Astrophysical Phenomena

Discovery of a 62-min long-period transient with near-orthogonal rotator geometry

Scott D. Hyman, Natasha Hurley-Walker, Dale A. Frail et al. (+2 more)

We report the serendipitous discovery of J155543.7$-$563102 (hereafter LPT J1555$-$5631) with a period of 62.2 min in MeerKAT and ASKAP survey data. The source emitted bright (10-30 mJy), steep-spectrum ($\alpha\sim-1.5$), highly polarized radio pulses during a 15-hr active window in May 2022, with no other quiescent or pulsed emission detected before or after over $\sim5$ years. The mean light curve exhibits two alternating pulses per cycle. A main pulse (MP) and an interpulse (IP) separated by $\Delta\phi=165.4^\circ$ with similar amplitudes, but different polarization properties: the wider MP (3.9%) is partially linearly and circularly polarized and shows a constant polarization position angle, while the narrow IP (1.1%) is $\sim$100% circularly polarized. We classify LPT J1555$-$5631 as a near-orthogonal rotator, for which emission from both magnetic poles is visible during one rotation and the magnetic and rotation axes are almost perpendicular. The 14.6$^\circ$ deviation from an antipodal separation and the nearly constant polarization position angle suggest that the emission does not arise from the standard dipolar polar-cap geometry of ordinary pulsars, but instead originates within a broader, more complex magnetosphere. The observed properties of LPT J1555$-$5631 can be accommodated by extended emission regions, and favor coherent emission mechanisms such as the electron cyclotron maser instability, although they do not uniquely determine the progenitor or emission physics. If these inferences apply more broadly to the LPT population, they could account for why their beam widths are decoupled from rotation periods, the prevalence of flat polarization position angles, and may favor an elevated incidence of orthogonal rotators.
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All authors Scott D. Hyman, Natasha Hurley-Walker, Dale A. Frail, Emil Polisensky, W. D. Cotton