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Wednesday 30 September

General Relativity and Quantum Cosmology

Poisson spot and wave scattering of scalar fields by conformal anomaly black holes: probing the near-horizon geometry

We investigate the scattering and diffraction of scalar plane waves by static conformal anomaly black holes. We determine the truncation requirements for the partial-wave series (PWS) method at finite distances and compute the full waveforms, which display a clear diffraction pattern: on the negative $z$-axis the field reduces to the incident plane wave, while on the positive $z$-axis a distorted plane wave coexists with a scattered spherical wave, and a bright Poisson spot appears at $\theta=0$ surrounded by concentric diffraction rings. We obtain the on-axis intensity of the Poisson spot as a function of the radial coordinate. The intensity is most sensitive to the near-horizon geometry: close to the horizon it differs markedly from that of the RN black hole, whereas in the far field the two curves converge. We trace this to the metric functions, where different values of $f'(r_+)$ produce different phase increments that compress and shift the interference fringes, while the conformal anomaly correction falls off as $O(\tilde{\alpha}M^2/r^4)$. By analyzing the potential barrier we study the absorption cross section, and use the series reduction method to accelerate the PWS convergence for the differential scattering cross section. The low- and high-frequency absorption cross sections are strongly correlated with the $\ell=0$ and $\ell$-dependent parts of the potential barrier, respectively. The differential cross section and glory scattering arise mainly from scattering in a finite region excluding a small neighborhood of the outer horizon. Charge and $\tilde{\alpha}$ have opposite effects on the width of the glory peak but the same effect on its height.
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All authors Zeming Zhuang, Hongsheng Zhang, Zong-Kuan Guo, Rong-Gen Cai

Materials Science

An electromechanically coupled multiphase-field model with generalized kinetic relations for ferroelectrics

Classical phase-field models typically use the Allen–Cahn evolution law to model interface motion as a consequence of energy-gradient descent. This implies a linear kinetic relation between the velocity of an interface (e.g., a domain wall in a ferroelectric) and its driving force. When nonlinear kinetic relations are to be modeled, as commonly found in ferroelectric ceramics, an alternative evolution law and hence an alternative model is needed. Here, we propose an electromechanically (stress-driven) coupled multiphase-field framework with a general kinetic formulation, which integrates a prescribed kinetic relation directly into the evolution law. We show that this model correctly evolves domain walls with the assigned nonlinear kinetics, e.g., of mixed exponential-power law type, following the so-called Merz–Stadler law. The multiphase formulation further enables distinct kinetic relations and interfacial energies to be assigned to different order-parameter pairs, which reflects the distinguishable properties of the different types of ferroelectric domain walls. The proposed framework is broadly applicable for simulating kinetic relations in materials with applications beyond ferroelectrics.
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Quantum Physics

Separable decompositions of 2xn states with operator Schmidt rank three

We prove that every bipartite state $\rho$ of a qubit coupled to an $n$-level system whose operator Schmidt rank equals three can be written as a mixture of $\text{rank}(\rho)$ pure product states, and as a mixture of at most $n+1$ mixed product states in general. The second result is tight in the sense that there exist states that cannot be decomposed with a smaller number of terms. Our proof gives constructive methods to obtain the decompositions. It involves eigendecompositions of suitable unitary dilations of an operator explicitly determined by the state. Our framework recovers previously known results for the length of decompositions into pure product states and is also able to deal with decompositions into mixed states. For pure product states, our decomposition is different from existing ones.
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Quantum Physics

QMA(2) with Limited Shared Entanglement

In $\mathsf{QMA}(2)$, two computationally unbounded provers submit unentangled quantum witnesses to a polynomial-time quantum verifier. We ask whether allowing limited shared entanglement between the two provers changes the power of $\mathsf{QMA}(2)$. To this end, we formalize $\mathsf{QMA}(2;h)$, a variant in which the provers initially share $h$ EPR pairs, as suggested by Aaronson, Beigi, Drucker, Fefferman, and Shor (ToC~2009). We show that polynomially many shared EPR pairs give the provers no cheating advantage: $\mathsf{QMA}(2)\subseteq\mathsf{QMA}(2;h)$ for $h=\operatorname{poly}(n)$. For logarithmically many pairs, the power of $\mathsf{QMA}(2)$ remains unchanged, strengthening this inclusion to $\mathsf{QMA}(2)=\mathsf{QMA}(2;h)$ for $h=O(\log n)$. Finally, we introduce a variant that also allows classical communication between the provers when preparing the witnesses. This setting is particularly revealing for logarithmic-size witnesses: assuming $\mathsf{NP}\nsubseteq\mathsf{BQP}$, we show that superlogarithmically many shared EPR pairs strictly reduce the model's computational power.
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General Relativity and Quantum Cosmology

Spherical thin shells with charge in unimodular gravity

We construct spherically symmetric thin shells in unimodular gravity (UG) and analyze their dynamical stability under radial, symmetry-preserving perturbations. We use the UG junction conditions and adopt non-conservative charged exterior solutions sourced by a radial electric field. As an application, we build charged vacuum bubbles: a Minkowski interior surrounded by a charged thin shell and matched to an exterior UG geometry. The resulting spacetimes are free of event horizons and central singularities, while in de Sitter-like cases a cosmological horizon may exist outside the shell. We compare the stability regions and the matter content with their counterparts in general relativity, finding some differences controlled by the UG non-conservation parameter. This work extends previously published results.
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Statistical Mechanics

CYNAR: a trajectory-based estimator of entropy production

Inferring the entropy production rate $\sigma$ from recorded trajectories is a key challenge in stochastic thermodynamics. In experiments, the forces governing the dynamics are usually unknown and often only some of the system's degrees of freedom can be observed. Building on a recently introduced method [I. Di Terlizzi, Phys. Rev. Lett. 135, 237101 (2025)], we develop and validate CYNAR (computation yields nonequilibrium analysis and reconstruction), a pipeline that estimates $\sigma$ from trajectories. It exploits a kinetic decomposition of $\sigma$ into a traffic term ${\cal T}$, inferred from the short-time curvature of correlation functions, and an inflow rate ${\cal G}$, computed from the steady-state score, i.e., the gradient of the log-density. We show that the same decomposition, evaluated on any subset of observed coordinates, always bounds $\sigma$ from below, for any diffusion tensor and without knowledge of the hidden degrees of freedom. We then compare CYNAR with a more standard approach that estimates $\sigma$ from steady-state probability currents, on four systems of increasing complexity. CYNAR proves to be more reliable, with no detectable bias close to equilibrium, weak dependence on spatial discretization, and marked robustness to measurement noise. It is also readily applicable to high-dimensional systems, where the traffic alone provides a lower bound close to $\sigma$, and remains informative under partial observation, including cases where the flux-based estimate vanishes identically. CYNAR is provided as an open-source Python package.
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High Energy Physics (Experiment)

Measurement of the triple-differential cross section of Z+jet production in proton-proton collisions at $\sqrt{s}$ = 13 TeV

A measurement is presented of the triple-differential production cross section of Z/$\gamma^*$($\to$ $\mu\mu$)+jet events using proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the CMS experiment at the CERN LHC. The data, collected in the years 2016$-$2018, correspond to an integrated luminosity of 138 fb$^{-1}$. The cross section is measured as a function of the transverse momentum of the muon pair, the boost in rapidity of the center-of-mass system of the muon pair and the leading jet with respect to the laboratory frame, and half of their absolute rapidity separation. This choice of observables ensures sensitivity to the scattering angle in the center-of-mass frame and the fractional momenta of the interacting partons. After unfolding for detector effects in all three dimensions simultaneously, the results are compared with predictions at next-to-next-to-leading order in perturbative quantum chromodynamics corrected for electroweak and nonperturbative effects. This measurement provides valuable information towards characterizing the partonic structure of the proton and determining the strong coupling.
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Quantum Physics

Phase-sensitive avalanche quantum sensing of sub-shot-noise fields

Avalanche-based detection of small perturbations is commonplace in precision measurement devices from Geiger counters to single-photon avalanche detectors. Here, we expand this principle to sensing of light waves below the quantum shot noise limit, demonstrating numerically how atomic clouds trapped in photonic cavities can exhibit non-perturbative sensitivity to changes in the cavity field when the cavity mode is tuned to a parity-prohibited transition. We find that, when pumped by a continuous-wave laser, the atomic cloud creates emissions which amplify the initially sub-shot-noise fluctuation by two orders of magnitude. Crucially, this amplification is broadly tunable with respect to frequency and independent of atomic energy structure. Even more strikingly, our amplification mechanism preserves the phase imparted on the atoms by the original ultra-weak light wave, marking a qualitative improvement over conventional protocols. Our finding has implications for both quantum state characterization and detection of weak classical signals.
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High Energy Physics (Phenomenology)

Diffractive Vector-Meson Production from the Light-Front Quark Model

We study exclusive diffractive electroproduction of the $\rho^0$, $\phi$, $J/\psi$, and $\psi(2S)$ mesons in the color-dipole picture using two spin-orbit light-front wave functions, S-1 and S-2. S-1 follows from the Melosh–Wigner rotation in the light-front quark model (LFQM), while S-2 is the spin-improved form commonly used in holographic and boosted-Gaussian approaches. Both share the same radial wave function, with their parameters determined from the LFQM Hamiltonian. The color-glass-condensate dipole parameters are fixed from inclusive structure-function data, with no fit to diffractive data. We compare the predictions with measurements of cross sections, $R=\sigma_L/\sigma_T$, $t$ and $W$ dependences, and $\sigma_\phi/\sigma_\rho$. S-1 gives a better description of the light-meson observables, while S-2 provides a better description of the charmonium ratio $\sigma_{\psi(2S)}/\sigma_{J/\psi}$ and the $J/\psi$ decay constant. We also present the charge, magnetic, and quadrupole form factors of the four mesons and compare them with available lattice-QCD results.
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Mathematical Physics · Cross-listed from math.AP

Explicit Robin Green's Functions, Resonance Spectra, and Impedance Recovery on Annuli and Spherical Shells

This paper constructs explicit closed-form Green's functions for the Helmholtz equation on annular and spherical-shell domains with two independent Robin impedances on the inner and outer boundaries. Graf's and the hyperspherical addition theorems reduce each angular mode to an explicit $2\times2$ linear system, and the resonance spectrum is governed by a characteristic determinant bilinear in the two impedances. This bilinearity has a direct inverse-problem consequence: two resonant frequencies of one non-radial angular mode generate at most two candidate impedance pairs via an explicit quadratic equation, a third resonance selects the physical pair, and an exact reflection-symmetry obstruction identifies where the radial spherical mode cannot recover the impedances. Spectrally, we prove the branches positive, simple and strictly increasing in both impedances; derive first-order asymptotics at the four corners of the impedance plane, with coefficients given by boundary masses and normal derivatives of the limiting eigenfunctions, and an explicit mixed second-order coefficient at the Dirichlet–Dirichlet corner, which for the radial mode evaluates in closed form to $2\pi/(R_2-R_1)^3$; establish a low-frequency resonance-free band, with a second-order threshold expansion explicit in dimension three and a rational approximation accurate over the whole impedance range; and prove the universal high-frequency spacing law with a shell-curvature correction. Jacobian-based sensitivity and conditioning criteria are included. The kernels and spectra are computable to machine precision, all asymptotic regimes are confirmed numerically, and the kernels provide reference solutions for finite-element and boundary-element validation.
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General Relativity and Quantum Cosmology

Neutrino Oscillations without Mass: A Re-analysis of KamLAND Data following the Dirac Equation in Curved Spacetime

The Dirac equation in stationary curved spacetime implies that describing two-flavor neutrino oscillations requires treating the invariant mass and conserved energy of each propagating state distinctly, as gravity affects energy differently than mass. By re-analysing the publicly released KamLAND dataset, we show that modeling flavor states of massless neutrinos as two-level quantum states with energy-dependent level splitting, analogous to modified Jaynes-Cummings models, results in a higher-likelihood fit to the observed data than the standard massive-neutrino paradigm.
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Quantum Physics

Weakly Measured Loops for Quantum Amplitude Amplification: Oracle Savings and Adaptive Search with Unknown Target Probability

We present a family of quantum amplitude amplification algorithms that interleave ordinary Grover rotations with tunable weak measurements in loops. A successful measurement yields the target state and stops the algorithm, while after a failure, the loop resumes from the post-measurement state without restarting. We express the leading costs in expected Grover iterations as $p \to 0$. For a known target probability $p$, an exact weak measurement-conditioned loop for states near the angle $\pi/4$ uses $(\pi/8+1/4+o(1))/\sqrt{p}$ iterations, improving on the standard Grover constant $\pi/4$ and on optimised restart Grover, and matching the corresponding infimum in our continuous-angle analysis. When only a lower bound $0 < p_0 \leq p < 1/2$ is available, a discrete Lyapunov equation gives the exact expected oracle cost for every fixed measurement strength and a closed-form optimal strength. Using the strength selected from $p_0$, the expected number of Grover iterations is at most $\frac{1}{2\sqrt{2}}(\frac{1}{\sqrt{p}}+\frac{1}{\sqrt{p_0}})$, where the expected cost decreases as the actual $p$ increases, and gives the leading constant $1/\sqrt{2}$ at the promise boundary $p = p_0$. For completely unknown $p$, we identify measurement strength $\kappa(t)=\Theta(1/t)$ as the critical scale within the regular schedules considered here and analyse $\kappa_b(t)=\min\{1/2,b/t\}$. For each fixed $b > 2$, we rigorously derive a closed-form Gamma-function expression $C(b)$ giving $(C(b)/2+o(1))/\sqrt{p}$ expected iterations. Numerical minimisation of this explicit expression gives $b \approx 5.2$ and $C(b)/2 \approx 1.01$. The results show that weak measurements preserve the $\Theta(1/\sqrt{p})$ search scale while adding an explicit fixed-point control mechanism and provable oracle savings.
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Mesoscale and Nanoscale Physics

Anisotropic wavevector-dependent damping of thickness-quantized magnons

Magnon damping is a key factor governing spin-wave transport and nonlinear dynamics of multimode magnon systems. However, many descriptions rely on the assumption of an effective mode-independent parameter, which can mask wavelength-dependent relaxation processes that depend on propagation geometry and mode profile. Here, we employ high-resolution parametric-instability spectroscopy to probe thickness-quantized spin waves with wavelengths down to about a hundred nanometers in micrometer-thick yttrium iron garnet films. The instability threshold exhibits a regular sawtooth dependence on the magnetic field, arising from switching between discrete thickness modes. Comparison with dipole–exchange theory reveals anisotropic wavevector-dependent damping that increases with mode number and depends differently on the in-plane and out-of-plane wavevector components.
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All authors Tamara Azevedo, Rostyslav O. Serha, Yannik Kunz, Matthias R. Schweizer, Vitaliy I. Vasyuchka, Mathias Weiler, Andrii V. Chumak, Burkard Hillebrands, Mikhail Kostylev, Alexander A. Serga

General Relativity and Quantum Cosmology

Complete total-transmission modes of Kerr black holes

We construct the complete spectrum of gravitational total-transmission modes (TTMs) of Kerr black holes and find four globally continuous families, $n_\infty=1,2,3,4$, each with two complex-conjugate frequency branches. Compared with the three-family classification of Cook and Lu, our global continuation resolves the mirror-related sectors of their $n=2$ family into separate families without introducing additional symmetry-unrelated roots. This organization distinguishes complex conjugation at fixed $m$ from the mirror symmetry connecting the $m$ and $-m$ spectra. The $n_\infty=3$ family approaches the Schwarzschild algebraically special frequency, whereas the $n_\infty=1,2,$ and $4$ families diverge as $\omega\propto a^{-4/3}$ along lower-half-plane directions $-150^\circ$, $-90^\circ$, and $-30^\circ$, respectively. High-precision data up to $\ell=32$ confirm the Cook–Lu small-spin asymptotics and reveal how the divergent branches are embedded in the global four-family spectrum, with a family-dependent relation between the spherical-limit angular labels and the large-$|a\omega|$ ordering. For axisymmetric perturbations, the $n_\infty=2$ and $n_\infty=3$ branches coalesce at genuine exceptional points, where the scattering spectral function develops a second-order zero and the TTM excitation factors are strongly enhanced, offering a different interpretation of the structure previously described by Cook and Lu as an overtone-multiplet splitting. Finally, we identify a previously unreported anomalous proximity between the $n_\infty=3$ TTM family and an unconventional Kerr quasinormal-mode sequence, with frequency separations reaching order $10^{-8}$ in the representative case studied.
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All authors Changkai Chen, Xiaohua Zhang, Zhoujian Cao, Jiliang Jing, Sheng Long

Cosmology and Nongalactic Astrophysics

An LSST-DESC Precursor Project: Hyper Suprime-Cam Year 1 $3\times2$pt in Harmonic Space

We present the first fully photometric joint analysis of weak gravitational lensing and galaxy clustering (3$\times$2pt) in harmonic space with LSST-DESC analysis pipelines applied to Hyper Suprime-Cam Year 1 (HSC Y1) data. The HSC Y1 dataset, with imaging depth and galaxy number density similar to those expected for the first year of LSST observations, is an ideal testbed for validating DESC measurement and inference tools. We measure the full set of angular power spectra - cosmic shear, galaxy clustering, and galaxy-galaxy lensing - perform null tests, and correct for the impact of observing conditions on both the galaxy density and shear fields via mode deprojection. We validate our likelihood pipeline by reproducing the official HSC Y1 cosmic shear cosmological constraints with the DESC inference code. Jointly analysing all three two-point functions, we constrain $\Lambda$CDM and $w$CDM cosmologies, reporting results for cosmic shear, the combination of galaxy clustering and galaxy-galaxy lensing (2$\times$2pt), and the full 3$\times$2pt. From the joint 3$\times$2pt $\Lambda$CDM analysis we find $\Omega_m = 0.249^{+0.061}_{-0.051}$, $\sigma_8 = 0.904^{+0.098}_{-0.091}$, and $S_8 \equiv \sigma_8\sqrt{\Omega_m/0.3} = 0.821^{+0.018}_{-0.021}$. This analysis validates the complete DESC 3x2pt infrastructure on survey data, providing the foundation for the forthcoming LSST Year 1 cosmological analysis.
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All authors D. Sanchez-Cid, J. Sanchez, I. Sevilla-Noarbe, D. Alonso, F. Andrade-Oliveira, H. Awan, C. Chang, J. Ellison, C. García-García, M. Ishak, E. Longley-Phillips, R. Mandelbaum, A. Nicola, E. Pedersen, J. Prat, E. Rykoff, E. Sanchez, N. Šarčević, M. Soares-Santos, M. Yamamoto, J. Zuntz, the LSST Dark Energy Science Collaboration

Quantum Physics

Warm-Start Iterative QITE for Distribution Network Reconfiguration via Branch-Exchange Encoding

We present a hybrid quantum-classical algorithm for distribution network reconfiguration, a combinatorial optimization problem on power distribution networks, that combines a radiality preserving branch-exchange encoding with iterative warm-start quantum imaginary-time evolution to minimize active line losses. The encoding uses a fixed-width binary representation of sequential branch-exchange actions, ensuring that every register outcome decodes to a radial configuration. The quantum subroutine is informed by a surrogate model fit to classically-solved alternating current power flow (ACPF) labels. After a set budget of ACPF solves and circuit samples is exhausted, the algorithm returns the lowest-loss configuration seen. We employ our algorithm on ten test cases, including seven commonly-used benchmark cases and three cases we modified from these and similar standard systems. We include two methods to reduce problem size, which enable extensions of the algorithm to larger networks. We successfully reach minimal-loss configurations for six cases and find configurations with losses from 0.2 percent to 2.18 percent above the reported reference minimal loss for the other four.
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All authors Noah Crum, Pete Pritchard, Tanner Rase, Phillip C. Lotshaw, Shaked Regev, Claudio Girotto, Ananth Kaushik, Paul Smith

High Energy Physics (Phenomenology)

The holographic QCD critical point is sensitive to quark flavors

We study the phase structure of dense QCD matter by applying the flavor-dependent holographic V-QCD model to two distinct physical environments: charge-neutral, beta-equilibrated matter, and strangeness-neutral matter with a fixed charge-to-baryon number ratio, n_Q/n_B = 0.4, relevant for heavy-ion collisions. The quark sector of the model incorporates the realistic mass hierarchy of two massless light quarks and a massive strange quark. We find that the resulting phase diagram depends sensitively on both the procedure used to tune the model against lattice QCD thermodynamics and the choice of physical environment. Using our preferred fitting procedure, we find that beta-equilibrated matter exhibits a first-order phase transition terminating at a critical endpoint located at significantly lower densities than in earlier holographic studies. However, this phase transition disappears entirely under heavy-ion conditions. This pronounced environmental dependence may help explain why recent net-proton cumulant measurements from Phase II of the RHIC Beam Energy Scan have not yet revealed clear non-monotonic fluctuation signatures. We calculate higher-order baryon number cumulant ratios along the chemical freeze-out curve to quantitatively compare the model predictions with experimental data. Finally, we also present global phase diagrams obtained by matching V-QCD to Hadron Resonance Gas models implemented in the Thermal-FIST package, and argue that this comparison further supports the conclusions drawn from the V-QCD model alone.
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All authors Niko Jokela, Matti Järvinen, Toshali Mitra, Aleksi Piispa

Quantum Physics

Thermodynamics of Ahn–Doherty–Landahl Continuous Quantum Error Correction

Continuous quantum error correction (CQEC) replaces discrete syndrome measurements and recovery operations with continuous syndrome extraction and real-time Hamiltonian feedback. Here we investigate the thermodynamic resources required by this process by formulating measurement-based continuous quantum error correction as an information engine. We distinguish the system-side power associated with energy transfer between the feedback field and the protected system from the controller-side power associated with the feedback Hamiltonian. The framework is first developed for the one-qubit Ahn-Doherty-Landahl (ADL) protocol and subsequently extended to the three-qubit repetition code under continuous stabilizer monitoring. Numerical simulations show that increasing the feedback strength improves the steady-state fidelity and reduces the conditional-state entropy, while both energetic contributions continue to increase in magnitude after the fidelity begins to saturate. These results expose a direct tradeoff between logical stabilization and the energetic resources required for continuous feedback, closely related to previously established energy–precision tradeoffs in quantum measurement and quantum-Zeno stabilization.
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Quantum Physics

The Complexity of Single-Interaction Hamiltonians

We study the complexity of Local Hamiltonian problems under the restriction that every local term is an unweighted occurrence of the same fixed interaction. In the resulting Single-Interaction Hamiltonian (SIH) model, once the interaction is fixed, the Hamiltonian is specified entirely by its ordered interaction hypergraph. Our main technical tool is an exact compiler that converts any fixed finite alphabet of local interactions into a single interaction. On a designated auxiliary subspace, the compiled Hamiltonian reproduces the source Hamiltonian exactly, while the complete spectrum below a chosen separation scale is preserved with multiplicity. Combined with a finite-alphabet normalization, this gives a universal polynomial-time reduction from $k$-Local Hamiltonian to SIH$_{3k+3}$ up to a known global energy scale and inverse-polynomial approximation. Sharper constructions give QMA-completeness of SIH$_3$ and of geometrically local SIH$_8$ with bounded degree and interaction range. In the stoquastic setting, we obtain StoqMA-completeness of Stoq-SIH$_3$ and QMA-completeness of 1-Pinned Stoq-SIH$_4$. We also establish hardness results for uniformly system-size-dependent interactions and derive single-interaction formulations of the Hamiltonian quantum PCP conjecture, frustration-free, exponentially precise, and guided Local Hamiltonian problems. These results show that independently chosen local matrices and independently tunable coupling strengths are not necessary for a broad range of Hamiltonian-complexity phenomena.
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Quantum Physics

Rate 1/5 Non-Malleable Codes against Entangled Split-State Tampering

We construct efficient information-theoretic non-malleable codes for classical messages that are secure against two noncommunicating local quantum tampering operations with arbitrary pre-shared entanglement. For every sufficiently small fixed $\xi>0$ and all sufficiently large first-share lengths $n$, the codes have rate at least $1/5-\xi$, perfect correctness, and error $2^{-n^{\Omega(1)}}$. Security holds for every message, with a single message-independent simulator for each attack. This resolves the constant-rate question for worst-case classical messages in the entangled two-split-state model. Our construction builds on the permutation-based two-split construction of Batra, Boddu, and Jain, which achieves rate approaching $1/5$ for uniformly random messages. We retain their architecture but replace the uniform message input to the permutation with a prescribed message concatenated with fresh uniform padding. Our main contribution is a worst-case security reduction for this modification.
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Optics

How Shaped Waves Propagate in Scattering Media

The radiative transport equation provides a powerful framework for describing wave propagation in scattering media. However, it cannot describe coherent waves whose incident wavefront is deliberately tailored. Here we establish a transport theory for wavefront-controlled waves based on a matrix transport equation. Unlike conventional radiative transport, which propagates a scalar radiance, our theory propagates a complex two-by-two matrix that retains phase information and obeys a nonlinear transport equation, despite the underlying wave dynamics being linear. We use this matrix transport equation to derive the spatial profiles of the energy and current densities of transmission eigenchannels, from closed to open channels, in arbitrary diffusive systems. Remarkably, these profiles can be expressed analytically in terms of the solution of the conventional radiative transport equation for a random wave in the same medium. The theory further extends to energy loss, including absorption and leakage into uncontrolled channels, revealing symmetry breaking of transmission eigenchannels in complex structures. Validated against numerical solutions of the wave equation, we establish matrix transport as a framework for describing and controlling coherent wave propagation in complex media.
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General Relativity and Quantum Cosmology

MADGRAV: a multilevel anomaly-detection pipeline for gravitational-wave searches applied to LIGO data

We present the results of MADGRAV, a deep-learning-based search for high-mass compact binary coalescences, applied to the data collected by the LIGO interferometers during the third observing run and during the first and second part of the fourth observing run. The MADGRAV pipeline consists of a series of sequential convolutional neural networks that perform anomaly detection, glitch classification, coherence testing, and signal ranking. Data from the Hanford and Livingston LIGO detectors are studied (both individually and in coherence) by way of 1 second Q-transform windows. Of the candidates that survive every stage of the pipeline, 48 reach the significance threshold, and we report 47 gravitational wave detections characterised by a false alarm rate below $1\,{\rm yr}^{-1}$ with a probability of astrophysical origin $p_{\rm astro}>0.9$. Of the 47 detections, 44 are shared with the minimally modelled coherent WaveBurst search. The observed total source-frame masses, extracted from official gravitational wave transient catalogues, are in the $14-236 M_{\odot}$ range with a median of $69 M_{\odot}$, and a median SNR of 16. We note that the recovered fraction of confident detections rises with mass: for LIGO detectors network SNR $>10$ the pipeline recovers $8.1\%$ of confident catalog events below $30 M_{\odot}$, $39.8\%$ between $30$ and $100 M_{\odot}$, and $53.3\%$ above $100 M_{\odot}$, corresponding to $33.3\%$, $45.5\%$ and $53.3\%$ of the events detected by coherent WaveBurst in the same bins. These results suggest that anomaly detection pipelines can serve as an independent detection channel complementary to matched filtering in the high-mass high-SNR regime.
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All authors Gianluca Inguglia, Huw Haigh, Ulyana Dupletsa, Alessandro Longo

High Energy Physics (Phenomenology)

On the Role of Diffractive Production in Precision Studies of W and Z Bosons at the LHC

The increasing precision of measurements at the Large Hadron Collider requires a detailed understanding of all contributions to electroweak boson production. We estimate the impact of single-diffractive W and Z production on precision observables at $\sqrt{s}=5$, 7, 8, and 13 TeV. The non-diffractive baseline is calculated with DYTurbo, while Herwig provides the relative single-diffractive contribution and its transverse-momentum dependence. Factorization breaking is incorporated through a $p_T$-dependent rapidity-gap survival probability calculated with the dynamic multiparton-interaction model of Pythia8. The diffractive Asimov spectrum is constructed by deterministic bin-by-bin reweighting of the same high-numerical-precision DYTurbo cross section used for the non-diffractive baseline. With the non-perturbative parameters profiled, the nominal relative shifts in $\alpha_s$ are -0.0072%, -0.043%, -0.070%, and -0.067% at 5, 7, 8, and 13 TeV, respectively. Five Pythia8 Pomeron-flux and diffractive-PDF configurations give a maximum spread of $9.4\times10^{-6}$ in $\Delta\alpha_s$. In the W-mass study, the largest bias from an unmodelled survived single-diffractive contribution is 1.58 MeV, and the largest residual after applying the corresponding model-matched template correction is 1.14 MeV. These shifts are below the relevant fit precision, and no phenomenologically significant impact on $m_W$ is expected within the tested models.
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High Energy Physics (Phenomenology)

Exact color sums for multi-gluon amplitudes: direct, multiplet and symmetric-group Fourier methods

We compare three approaches for computing color-summed tree-level all-gluon squared matrix elements: evaluation using direct contraction in the trace and adjoint decompositions, orthonormal multiplet bases, and fast Fourier transforms (FFT) based on the irreducible representations of the symmetric group for the trace and adjoint decompositions. The multiplet method reduces the color sum to a sum of absolute squares and utilizes an amplitude recursion labeled by SU(3) representations. The FFT exploits the relative-permutation dependence of color overlaps to replace the direct double sum with smaller independent contractions, using standard color-ordered partial amplitudes. This invokes the symmetric group at the level of gluon labels, and therefore makes maximal use of the permutation symmetry. We compare CPU time and memory use for four through eleven gluons. At eleven gluons, the direct adjoint contraction evaluates a fixed-helicity color-summed matrix element in an estimated 1.7 10${}^3$ s after initialization, compared with 19.8 s for the multiplet recursion and 0.814 s for the FFT adjoint method. The adjoint FFT is fastest from six through eleven gluons, despite its factorial scaling compared with the exponential scaling of the multiplet recursion.
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Instrumentation and Methods for Astrophysics

ArxSP: A Python-Based Modular Application for the Reduction of Digitized Archival Spectra

We present a methodology for the reduction of archival spectral data together with the description of a newly developed Python-based software package featuring an interactive graphical interface. The work is primarily aimed at processing spectra obtained with electron-optical converters (EOCs), which are characterized by geometric distortions induced by the magnetic field of the registration system. Such data are preserved, in particular, in the archive of the Fesenkov Astrophysical Institute (FAI), which contains about 10,000 photographic plates. These distortions, along with the need to transform the optical density of the photographic material into relative intensity, cannot be corrected by standard astronomical packages such as IRAF and therefore require a dedicated approach. Historically, reductions at FAI were performed using a program written in the Microsoft QuickC language for computing platforms of the 1990s, rendering it incompatible with modern operating systems. The new package is implemented with the PyQt5 framework, retaining the logic of the original code while extending its functionality. The implemented algorithms include image rotation and cropping, geometric distortion correction, construction of the characteristic curve linking optical density and intensity, and direct conversion of pixel values in object spectra. The developed software ensures reproducible reduction of archival spectra and provides a cross-platform environment with potential for further extensions.
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All authors Ildana Izmailova, Adel Umirbayeva, Manas Khassanov, Laura Aktay, Saule Shomshekova

Biological Physics

Axonemal bending stiffness of $\mathit{Chlamydomonas}$ cilia implies single-motor forces above $5\,\mathrm{pN}$

The regular bending waves of cilia and flagella provide an iconic model system for the collective dynamics of molecular motors. The known regular arrangement of dynein motors in a cilium's axoneme allows us to connect mesoscopic cilia properties, such as axonemal bending stiffness, to microscopic motor properties, such as the force exerted by an individual motor. We estimate the active force generated by the collection of dynein molecular motors in $\mathit{Chlamydomonas}$ axonemes using previous estimates of its bending stiffness. Divided by the maximal possible number of active motor heads, this provides a lower bound of ${>}10\,\mathrm{pN}$ for the peak force generated by a motor head, which exceeds typical stall forces ${<}5\,\mathrm{pN}$ of molecular motors. This discrepancy suggests that either the bending stiffness of microtubules and axonemes was previously overestimated, or that collective force generation in dense motor arrays can surpass the sum of expected contributions of individual motors.
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Quantum Physics

Exact Maximum Likelihood Decoding beyond Treewidth via Rank-Decomposition Dynamic Programming

Maximum-likelihood decoding provides an optimal decoding strategy for quantum error correction under stochastic Pauli noise. However, computing logical-class probabilities is challenging, and the leading exact tensor-network contraction requires time exponential in treewidth. In this work, we introduce a new decoding algorithm based on rank-decomposition dynamic programming (Rank DP). We express decoding partition functions with independent local fault factors as quadratic sums of powers and apply Rank DP. The resulting exact evaluator has arithmetic complexity polynomial in the input size and exponential in the Tanner graph's rank-width with respect to the fault partition, including decomposition construction. After Gaussian elimination, it gives polynomial-time decoding for punctured quantum Reed-Muller codes and a Steane-concatenated family with growing distance under independent single-qubit Pauli noise. Standard contraction of the corresponding tensor networks requires superpolynomial time. A nonnegative realization gives relative floating-point error bounds under explicit arithmetic assumptions. Numerical experiments demonstrate runtime advantages over the tested tensor-network implementations on selected code-capacity and circuit-level instances, with full likelihood evaluation for Reed-Muller codes up to $1{,}023$ qubits. We further use these likelihoods to learn circuit noise parameters from syndromes, evaluate rare postselection probabilities, and quantify decoder optimality gaps. Our work opens new avenues for exploiting algebraic structure in quantum decoding and noise characterization.
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Optics

Judd-Ofelt analysis of holmium-doped alumino-silicate optical glass prepared by MCVD combined with nanoparticle doping

We present a detailed Judd–Ofelt (JO) analysis of Ho$^{3+}$-doped alumino-silicate optical fiber preforms in a wide range of compositions and prepared by both the standard solution doping method as well as the more advanced nanoparticle doping. The absorption spectra were measured, the absorption cross sections were calculated for each observed transition, and the Judd–Ofelt analysis was conducted. The preforms exhibited the values of JO parameters of $\Omega_2 = (7.2--10.6) \times 10^{-20}\,\mathrm{cm}^2$, depending on the Al$_2$O$_3$ content, and $\Omega_4$ and $\Omega_6$ around $2.5$ and $1.2 \times 10^{-20}\,\mathrm{cm}^2$, respectively. The radiative transition parameters, such as transition probabilities, branching ratios, and radiative lifetimes, were calculated. The radiative lifetime of the ${}^5I_7 \rightarrow {}^5I_8$ transition, in the $16.1--17.2\,\mathrm{ms}$ range, combined with a measured value in the $0.9--1.9\,\mathrm{ms}$ range, was used to calculate the quantum efficiency, which was in the $5--11\,\%$ range. The preforms prepared by nanoparticle doping containing high Al$_2$O$_3$ contents above $8\,\mathrm{mol.}\,\%$ exhibited superior values of measured lifetime (above $1.5\,\mathrm{ms}$) and quantum efficiency (above $8\,\%$) compared to the standard solution-doped samples. To the best of our knowledge, this work is the first comprehensive report on the JO analysis of Ho$^{3+}$-doped alumino-silicate glass. The calculated parameters may be used in various calculations, simulations, and modelling of holmium-doped fiber lasers and other devices.
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All authors Petr Varak, Michal Kamradek, Pavla Nekvindova, Jan Hrabovsky, Pavel Peterka

Instrumentation and Methods for Astrophysics

FAIR-Compliant Architecture for Heterogeneous Astronomical Data: KazVO Framework

This paper presents the architecture of the Kazakhstani National Virtual Observatory (KazVO) - an International Virtual Observatory Alliance (IVOA) compliant node that unifies the heterogeneous observational datasets of the Fesenkov Astrophysical Institute (FAI). The architectural foundation of the system is built upon a partitioned Data Lake, a German Astrophysical Virtual Observatory (GAVO) Data Center Helper Suite (DaCHS) publishing backend, and a PostgreSQL database that maps heterogeneous metadata to the unified IVOA ObsCore standard. We follow Open Science by introducing metadata-only model featuring based on a four-class data embargo mechanism. Machine-to-machine services deployed via IVOA protocols are listed in the global Registry of Registers, enabling analysis of Kazakhstani observational assets within external clients such as Tool for OPerations on Catalogues And Tables (TOPCAT), Aladin, and PyVO. As a result, KazVO framework provides a scalable platform driven by a developed end-to-end pipeline that bridges two fundamentally distinct data types - digitized historical glass-plate heritage (1950-1997) and live operational photometric and spectroscopic digital streams from telescopes at the Assy-Turgen and Tien-Shan Observatories - opening FAI's combined data datasets to the global scientific and time-domain astrophysics community.
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All authors Ildana Izmailova, Denis Yurin, Yerlan Aimuratov, Maxim Makukov, Aleksander Serebryanskiy, Saule Shomshekova, Vitaliy Kim, Chingis Omarov, Adel Umirbayeva, Laura Aktay, Dana Kuvatova, Anton Gluchshenko, Gulnara Suliyeva, Maxim Krugov, Nadezhda Vaidman, Daulet Anarbek, Inna Reva, Gauhar Aimanova, Rashit Valiullin, Raushan Kokumbayeva

General Relativity and Quantum Cosmology

Phenomenology of dynamical trapped regions

Regular black holes (RBHs) and horizonless black hole mimickers (BHMs) are often studied as stationary alternatives to classical black holes, although their interiors may be unstable or undergoing relaxation. We investigate the phenomenological consequences of this evolution by numerically evolving linear scalar perturbations on prescribed, time-dependent Hayward-like geometries. We consider BHM–RBH–BHM histories in which an initially horizonless object temporarily develops a trapped region before returning to a horizonless configuration, through either a single bounce or a sequence of repeated bounces. Using horizon-penetrating Painlevé–Gullstrand coordinates, we follow the perturbations through the formation and disappearance of trapping horizons and compute the resulting waveforms and scalar-field energy. For histories with identical initial and final geometries, we find that changing the duration of the intermediate regular black hole phase produces differences in the amplitude and phase of the late-time signal, including its echoes. Longer trapped phases also yield greater energy amplification, consistent with the blueshift of outgoing modes near the inner trapping horizon. These results show that the late-time response of a dynamically relaxing BHM need not be determined by its final configuration alone: it can retain a memory of the dynamical history of its interior.
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All authors Julio Arrechea, Stefano Liberati, Hooman Neshat, Vania Vellucci