Papers

It has been argued that degenerate higher-order scalar-tensor theories and the effective field theory (EFT) of dark energy are endowed with the Vainshtein mechanism, resulting in a screened fifth force in the exterior of a gravitational source. However, spherical symmetry has been assumed in most of the discussions so far. In this paper, we study whether the Vainshtein mechanism operates in the EFT of dark energy beyond spherical symmetry, focusing in particular on the role of the “beyond Horndeski” EFT parameters. Assuming that deviations from spherical symmetry are small, we compute multipole moments of the gravitational potential for a given nonspherical source. For a generic choice of the “beyond Horndeski” EFT parameters, it is shown that the multipole moments of the fifth force are not screened in the region where the monopole component is screened. Rather, the gravitational potential shows a characteristic oscillatory behavior in its multipole components. In the special case where the EFT parameters are tuned so that graviton decay into dark energy is practically absent, the behavior of the multipole moments is qualitatively different from that in the generic case. However, also in this case, the Vainshtein mechanism is not efficient enough to screen the fifth force around the source.

The three-body decays of charmonium states provide a valuable laboratory for probing non-perturbative QCD dynamics and investigating light meson resonances. Three-body decays $\chi _{c1,2} \to P_{1}P_{2}P_{3}$ are studied in this work ($P$ denotes the light pseudoscalar meson). Branching ratio analysis is performed for the $\chi _{c1,2} \to P_{1}P_{2}P_{3}$ decays incorporating light vector ($V$) meson resonance, light tensor ($T$) meson resonance and light scalar ($S$) meson resonance contributions. Based on the SU(3) flavor symmetry approach, we calculate the branching ratios under both the narrow width approximation and the finite width effect, and provide the predict results in the $\chi _{c1,2}\to (V/T)P_{3} \to P_{1}P_{2}P_{3}$ processes. Furthermore, based on the significant $a^{+}_{0}(980)$ resonance signal in $\chi _{c1} \to \pi^{+ }\pi^{- }\eta$ decay, the predict results for $\chi _{c1}\to SP_{3} \to P_{1}P_{2}P_{3}$ are also obtained. While the resonance signals observed in current experiments are mainly concentrated in the $\chi_{c1} \to \pi^+ \pi^- \eta$ decay, our results suggest potential resonance contributions in other channels. Especially in $\chi _{c1,2}\to KK\pi$ channels, the predicted results show the significant resonance contributions from $V$ mesons and $T$ mesons, which is worth further experimental verification and exploration.

We investigate the production of several hidden-charm exotic candidates, including $Z_c(3900)$, $Z_c(4020)$, $Z_{cs}(3985)$, and $Z_2(4250)$, in $\psi(4660)$ decays under the assumption that these states are predominantly hadronic molecules. Treating $\psi(4660)$ as a conventional $\psi(5S)$ charmonium state, the production mechanisms are described through intermediate charmed-meson triangle loops, with its couplings to charmed-meson pairs estimated within the quark model. A systematic analysis of the processes $\psi(4660)\to Z_c(3900)\pi$, $\psi(4660)\to Z_c(4020)\pi$, $\psi(4660)\to Z_{cs}(3985)K$, and $\psi(4660)\to Z_2(4250)\pi$ is performed within a unified framework. The predicted branching fractions are found to be of the order of $10^{-2}$, $10^{-4}$, $10^{-3}$, and $10^{-6}$, respectively, exhibiting only a mild dependence on the cutoff parameter. We further find that the contributions from the $SHH$ intermediate loops dominate over those from the $THH$ and $HHH$ loops in most channels. The sizable production rates obtained in this work indicate that $\psi(4660)$ decays provide a promising platform for probing the molecular nature of charged hidden-charm exotic states and testing their underlying production mechanisms.

As fusion energy moves from theoretical feasibility toward commercialization, design of new reactor concepts, autonomous tokamak control, and high-performance scenario optimization are becoming increasingly important. Traditionally, such optimization tasks have relied on costly trial-and-error or brute-force parameter searches, based on black-box experiments or simulations. Recently, advances in differentiable programming are changing the paradigm of numerical simulation. Unlike conventional simulations, which are typically executed as locally connected step-by-step procedures, differentiable simulation represents the entire simulation pipeline as a connected computational graph. In such a framework, machine parameters, actuator waveforms, and plasma responses are linked through differentiable operations, allowing Jacobians to propagate across the full simulation. This enables direct gradient-based control and optimization using the internal sensitivities of the simulator, rather than treating the simulator as a black box. Here, we present TokaGrad, an end-to-end differentiable tokamak transport simulator for full-scenario modeling, including ramp-up, L-mode operation, and H-mode access. TokaGrad self-consistently integrates differentiable models for plasma equilibrium, transport, heating, L-H transition, and pedestal formation. To our knowledge, this is the first differentiable tokamak simulator capable of self-consistently modeling dynamic full-discharge scenarios where actuators and plasma evolve together with equilibrium, pedestal, and confinement-regime transitions. We demonstrate that, when coupled to gradient-based optimizers, TokaGrad enables reactor-design optimization, actuator control, and full-scenario waveform optimization. This framework provides a pathway toward automated, differentiable optimization of burning-plasma scenarios and reactor concepts.

Dynamically encircling exceptional points (EPs) enables chiral state conversion in classical wave systems. However, whether this mechanism can be extended to chiral spin conversion has remained elusive. Here we demonstrate chiral switching of elastic spin via dynamic encirclement of EPs in a non-Hermitian micropolar (Cosserat) metamaterial. The interplay between micropolar chirality and anisotropic loss generates EPs with a nontrivial Riemann-sheet topology. Encircling these EPs converts the elastic spin, with the final spin sign dictated solely by the handedness of the encircling trajectory. Our results establish a fundamental route for the selective manipulation of elastic spin, opening avenues for non-Hermitian spin phononics and broader applications in other wave systems.

Universal scaling behavior appears across a wide range of nonlinear systems despite substantial differences in their governing equations and physical mechanisms. We develop a renormalization-group (RG) framework that identifies two complementary RG mechanisms underlying such universality. First, scale invariance generates RG fixed points corresponding to asymptotic self-similar solutions. Second, repeated RG transformations eliminate non-scale-invariant irrelevant structures, causing broad classes of equations to flow toward the same fixed points and thereby form universality classes. The framework applies to finite-time singularities, long-time intermediate asymptotics, stochastic Edwards–Wilkinson growth, nonlinear diffusion, density-dependent biological diffusion, and fluid-interface dynamics. In each case, it reproduces known scaling behavior and identifies the associated universality class through explicit irrelevance criteria. A central feature of the framework is its predictive character. Once a scale-invariant fixed point is identified, the theory predicts entire families of nonlinear equations sharing the same asymptotic self-similar solution. While the diffusion class is partially supported by existing mathematically rigorous results, most universality classes identified here have not previously been established and therefore constitute testable predictions. These results provide a unified RG perspective on universality in nonlinear systems and show that universality emerges from the same fundamental RG principles that underlie critical phenomena.

Recently, we demonstrated that while an interstellar mission to the nearest black hole remains highly speculative and extraordinarily challenging, it is not entirely implausible within the coming decades. Given that such a mission would likely take about a hundred years and require substantial financial and human investment, it is essential to assess whether it could investigate black holes and test General Relativity to a degree that cannot be achieved by Solar System observatories for the foreseeable future. In Paper I, we assumed the capability to decelerate the spacecraft and presented a preliminary study of how orbiting probes could test the nature of the compact object. In this second paper, we study how the black hole can be tested without decelerating the spacecraft, using flyby probes.

Symmetry imposes fundamental constraints on quantum measurement and control. The Wigner-Araki-Yanase theorem and its quantitative extensions capture this restriction for continuous symmetries, in terms of fluctuations of conserved generators. Such generator-based bounds, however, do not provide quantitative limitations for discrete unitary symmetries or for antiunitary symmetries. Here we establish quantitative WAY-type theorems for symmetry-breaking projective measurements and unitary gates under arbitrary unitary and antiunitary symmetries. Our approach is based on a two-target no-programming inequality: if a single processor approximately implements two operations that amplify distinguishability, then the corresponding program states must themselves be distinguishable. Applied to symmetric implementations, this converts the error of an asymmetric measurement or gate directly into a lower bound on the asymmetry of the apparatus state, quantified by its fidelity with its symmetry-transformed copy. Our results apply to discrete and antiunitary symmetries, thereby providing a fundamental limit for symmetry-limited quantum measurement and control beyond the continuous-symmetry regime.

Multiscale fluid flows often contain localized flow structures, such as viscous shock layers, wet-dry fronts, steady viscous wakes, decaying vortical structures, and vortex-shedding patterns, whose accurate prediction requires the simultaneous preservation of global conservation trends and small-scale gradients. This study examines these flow-physics requirements through a physics-informed wavelet-Fourier (PIWF) representation for multiscale fluid dynamics. Instead of relying on a single monolithic neural approximator, the formulation separates two complementary components of the flow field within a physics-informed neural representation: long-range coherent modes through a Fourier-basis branch and localized steep-gradient or vortical features through a compactly supported wavelet branch. The outputs are fused with a residual multilayer perceptron using channel attention, and the governing equations, initial conditions, and boundary conditions are imposed directly through the physics-informed loss. The model is assessed on five canonical fluid-dynamics problems: Burgers' equation, the shallow water equations, Kovasznay flow, Taylor–Green vortex flow, and two-dimensional cylinder wake flow. The results show that PIWF improves the resolution of shock-like gradients, wet–dry interfaces, steady wake fields, decaying vortical structures, vorticity extrema, and broadband wake spectra relative to standard physics-informed neural networks and physics-informed Kolmogorov–Arnold networks. These findings indicate that a wavelet-Fourier physics-informed representation can provide a useful route for analyzing multiscale flow phenomena when high-fidelity interior reference data are limited or unavailable.

We define a two-particle quantum walk of identical particles on a graph $G$ via the one-particle Grover walk on the Kronecker product $G \otimes G$, and call it the two-particle Grover walk. In systems of identical particles, quantum mechanics requires that quantum states have a certain invariance with respect to the exchange of particles. Focusing on the symmetry of the Kronecker product $G \otimes G$ as a graph, we show that the time evolution operator of this walk commutes with the swap operator, which ensures that this requirement is satisfied. Furthermore, we study the entanglement entropy of quantum states evolved by this walk. For the complete bipartite graph $K_{n,n}$, we completely determine the values of $n$ for which the quantum states evolved from specific initial states attain the upper bound of the entropy at some time, and prove that they are exactly $1$ and $2$.

We investigate the dynamics of a dark-bright soliton in harmonically trapped two-component Bose-Einstein condensates and reveal an interesting spontaneous spatial symmetry breaking driven by nonlinear interactions. When the interaction parameter crosses a threshold value, we find that the dark-bright soliton's motion demonstrates a transition from symmetric periodic oscillation about the origin to asymmetric oscillations offset from the origin. In particular, at the transition point, the effective soliton mass, determined by the ratio of inertial mass to physical mass, diverges. The underlying mechanism is uncovered by constructing trial wave functions and employing the Lagrangian variational method to obtain an effective potential in the quasiparticle picture, which changes from a single well to a double well. The anomalous “superheavy soliton” phenomenon is a direct consequence of the dark-bright soliton's physical mass vanishing at the transition point. We obtain the phase diagram of this spatial symmetry-breaking transition. Possible implications of our finding for quantum metrology are discussed.

The light metal Al was predicted to have strong orbital Hall and Rashba effects from its bulk and interface, respectively. In this letter, we report experimental evidence that neither the bulk nor the interface of the Al contributed a detectable torque on adjacent Co and FePt layers with significant spin Hall effect, spin-orbit coupling, and resistivity mismatch with Al. These results suggest minimal orbital-spin conversion in Al and negligible orbital transport and spin-vorticity torque in Co/Al, Al/Co, and Al/FePt bilayers. Our findings suggest poor generality and/or effectiveness of torque contributions by the orbital Hall effect, the interfacial orbital Rashba effect, and the spin-vorticity coupling.

Quantum simulation of open quantum systems in the noisy intermediate-scale quantum (NISQ) era is hindered by the non-unitary nature of dissipative dynamics and the limited quantum resources available on near-term quantum processors, namely restricted qubit counts and noise-limited circuit depths. In this work, we propose an efficient quantum algorithm for simulating Lindbladian dynamics on NISQ devices. For open quantum systems with Pauli dissipations, we first derive a compact and stable mixed-unitary adjoint channel that approximates the target dissipative dynamics and enables ancilla-free implementation through trajectory sampling. To further reduce the circuit depth required for implementing the sampled trajectories, we introduce an adaptive variational quantum trajectory compression framework. In this framework, a depth-adaptive parameterized quantum circuit is trained to approximate repeated Hamiltonian simulation operators, which are then used to replace repeated unitary segments appearing in the sampled trajectories. Importantly, the training procedure can also be performed without auxiliary qubits. Numerical simulations of the dissipative quantum $XY$ model and the interacting disordered $XXZ$ chain demonstrate the accuracy and reduced execution gate counts of the proposed algorithm. Our results provide a practical route toward ancilla-free and depth-reduced simulation of open quantum systems on near-term quantum hardware.

This work studies the asymptotic stability of solutions to the good Boussinesq equation in dispersive wave region when the reflection coefficients associated with the initial data belong to weighted Sobolev space. The Dbar-steepest descent method is applied to the Riemann-Hilbert problem and the long-time asymptotic expansion of the solution are obtained up to an optimal error of order $\mathcal{O}(t^{-3/4})$. Compared with previous results, we extend the initial data from the rapidly decaying Schwartz space to a weighted Sobolev space, and prove the asymptotic stability of the solution in dispersive wave region.

Incompatibility constitutes a fundamental aspect of quantum mechanics. However, not every quantum observable non-classical property arises from incompatibility, nor can all quantum scenarios be fully captured by incompatibility alone. Within the framework of partial Boolean algebra (pBA), we research the structural properties of incompatibility scenarios. We introduce a unified method to realize any incompatibility scenario via a classical game, and the construction is extendable to any scenario embeddable into a Boolean algebra. The exclusivity graph offers a precise characterization of incompatibility scenarios. We prove that every exclusivity graph is the atom graph of an exclusive pBA, which is embedded into a Boolean algebra. These results provide a necessary condition for exclusivity graphs and a sufficient condition for atom graphs.

We present a new electromagnetic plasma simulation model with full-kinetic ions and drift-kinetic electrons. This model (termed as FIDES) solves the electric field using the implicit perpendicular Ohm's law and a novel implicit parallel Ampere's law, where the latter requires an implicit scheme for the parallel electric field in advancing the electron weights. To suppress unphysical high-frequency instabilities, ion weights are advanced using an implicit scheme for perpendicular electric fields. Simulations of perpendicular and parallel waves validate the model's capability in handling high-frequency physics. Low-frequency wave simulations demonstrate that the implicit parallel Ampere's law can mitigate the cancellation problem more effectively than the conventional schemes using the parallel Ohm's law. To reduce the numerical damping from implicit time-stepping, we develop a second-order scheme for particle pushing. Meanwhile, an integrated strategy combining the first- and second-order schemes is employed to suppress odd-even decoupling while maintaining the accuracy of the second-order formulation.

We present a concise and explicit analysis of logarithmically corrected black-hole thermodynamics and scalar scattering on the Schwarzschild branch of symmetric teleparallel gravity. Treating the metric and the flat, torsion-free affine connection as independent variables, we formulate the relevant nonmetricity geometry and field equations and show that the linear branch is dynamically equivalent to general relativity up to a boundary term. The vacuum solution is therefore the Schwarzschild spacetime. The leading entropy is derived from both the Noether-charge method and the classical first law, after which a logarithmic correction is introduced. When the geometry and ADM mass are kept fixed, the geometric Hawking temperature remains unchanged, whereas the temperature defined through the corrected first law is modified. The apparent divergence of the heat capacity occurs outside the regime in which the logarithmic expansion is reliable and therefore cannot be interpreted as a physical phase transition. We also derive the scalar radial equation, effective potential, conserved Wronskian, and reflection-transmission relation. For a neutral scalar field on a static neutral background, no superradiant amplification occurs, and the entropy correction produces no first-order change in the scattering amplitudes unless a genuine semiclassical backreaction or an explicit rotating or charged black-hole solution is provided.

The maximum mass of neutron stars provides a key constraint on the equation of state (EoS) of dense matter. Recent observations, including the ${\approx}2 M_{\odot}$ pulsar PSR~J0740+6620, have placed strong constraints on a large class of soft EoSs, while the possible existence of a compact object with a mass of $2.50$ - $2.67$ $M_{\odot}$ in GW 190814 further challenges our understanding of dense matter. Moreover, the inclusion of hyperonic degrees of freedom generally softens the EoS, making it difficult to support massive neutron stars even when the $2$ $M_{\odot}$ constraint is satisfied (a problem known as the hyperon puzzle). In this work, we investigate whether differential rotation can enhance the maximum mass of neutron stars constructed with an EoS including hyperons, thereby addressing the maximum-mass constraints imposed by current observations. We employ the Cook-Shapiro-Teukolsky (CST) approach, a numerically improved reformulation of the Komatsu-Eriguchi-Hachisu (KEH) scheme, to construct equilibrium configurations of differentially rotating neutron stars. For the nuclear matter EoS, we adopt a relativistic mean-field (RMF) model incorporating hyperonic degrees of freedom through an SU(6) symmetric coupling scheme. We find that differential rotation can substantially increase the maximum mass, yielding configurations consistent with the mass range inferred from GW 190814. However, a sufficiently soft EoS fails to satisfy the constraint from PSR~J0740+6620 (346 Hz) even with differential rotation applied. We also present a systematic analysis of the internal structure of the resulting equilibrium configurations. Furthermore, we demonstrate the existence of quasi-toroidal configurations and present equilibrium sequences incorporating the full baryon octet under extreme differential rotation.

A synchrotron injection scheme for the SuperKEKB electron high-energy ring (HER) was implemented and experimentally evaluated as the first attempt with a top-up injection during beam collisions. The lattice at the HER injection point was configured to provide a large horizontal dispersion of -1.6 m, and the injection beam energy was accordingly set to +0.6% above the ring energy. Since the beam extraction system is located near the injection point, the optics design was constrained to ensure compatibility with its requirements. A systematic tuning procedure of the injection parameters has been established with turn-by-turn BPMs(TbT-BPMs) in the ring, by which the betatron amplitude of the injected beam was successfully removed. Using optimized ring optics, synchrotron injection into the HER was successfully demonstrated, followed by the establishment of stable collisions and the production of luminosity.

We report the discovery and multiwavelength follow-up observations of a giant (factor >100) X-ray outburst of the exceptional changing-look active galactic nucleus (AGN) IC 3599. This is the third such outburst after two previous ones serendipitously discovered in 1990 and 2010. Based on our dedicated long-term monitoring of IC 3599 with Swift, the third outburst was detected while it was happening, and we triggered multiple follow-up observations within days to weeks for the first time. The Swift outburst spectra are supersoft and almost no photons are detected beyond 2.5 keV. The XMM-Newton short-term light curve shows a remarkable apparent oscillatory pattern that is reminiscent of quasiperiodic oscillations (QPOs). The optical high-state spectra reveal a multitude of bright coronal emission lines that have dramatically brightened and were absent or much fainter in low-state spectra. The new results eliminate outburst scenarios that require a constant time interval of repetitions (like certain variants of repeat tidal stripping, or of an orbiting supermassive black hole impacting the inner accretion disk), but remain in excellent agreement with an accretion disk radiation-pressure instability when assuming that local conditions in the disk of this long-lived AGN affect the onset time of each new instability. The combination of recurrent, giant, supersoft outbursts on decadal timescales, the exceptional emission-line response, and the rapid, candidate quasiperiodic, short-term variability on an hours timescale makes IC 3599 unique among AGN, and establishes it as a key system for studying accretion physics under extreme conditions and at the Eddington limit.

Quantum logic is usually presented as a non-classical departure from ordinary reasoning forced on us by quantum mechanics, with classical logic kept as the secure starting point. We argue for the opposite order of explanation in a finite and fully computable setting. The free orthomodular lattice on two generators has ninety-six elements, the direct product of a six-element non-distributive factor and a sixteen-element Boolean factor. Reading the first factor as a register of contexts and the second as Boolean content, we obtain a calculus whose elements are context–bit-vector pairs and whose operations act component by component. With this calculus we establish three results. First, we classify the six layers by commutativity, identifying the central kernel of context-neutral propositions together with a dual central layer in which all complementary contexts are present. Second, we show that orthocomplementation rearranges the layers exactly as the complementation of the small factor rearranges its elements, which makes the duality among the layers rigid rather than accidental. Third, we prove that the operation forgetting the context is a surjective homomorphism of orthocomplemented lattices whose quotient is the classical Boolean algebra, so that classical logic is a six-to-one, information-losing image of the contextual calculus.

We revisit the anomalous Hall effect in magnetic conductors, and its generalization to finite frequencies, using a formalism based on microscopic notions of polarization, magnetization, and free charges and currents. The electronic degrees of freedom are treated within second-quantized field theory, where the Hamiltonian features a static and cell-periodic magnetic field that encodes the magnetic order in the crystal and breaks time-reversal symmetry. We study the dynamics of bound and free charge carriers at the microscopic level as they respond to a spatially uniform electric field at finite frequency. The conductivity tensor describing the long-wavelength response is a sum of three terms, including a Kubo term associated with the polarization response, along with the metallic Drude term and the anomalous Hall conductivity that are associated with the longitudinal and transverse parts of the free current response, respectively. We also present numerical calculations of these contributions for the ferromagnetic body-centered cubic phase of iron.

We extend the persistent homology formalism done in references~\cite{paper1,paper2} to the Han Dynasty ($206~\mathrm{BCE}$–$220~\mathrm{CE}$), testing whether the collapse threshold $\Hstar = 0.5241$ and the three-network decomposition methodology established for the Roman–Byzantine case generalize to a mechanistically distinct imperial system. Three complementary networks are constructed from geospatial and historical data: an administrative network ($\Hadm$, 392~prefectures from CHGIS~v6), a geographic network ($\Hgeo$, with node end-dates extended beyond administrative dissolution), and an 81-node Silk Road trade network ($\Htrd$) as a structural control. Edge costs are derived via least-cost path analysis on a $1~\mathrm{km/pixel}$ digital elevation model, modulated by five historical friction channels. $\Hadm$ collapses to zero at 220~CE (phase~G slope $-0.0261~\mathrm{yr}^{-1}$, $R^2 = 0.689$) while $\Hgeo$ simultaneously increases to $3.065$, producing a divergence $\Delta H = 3.065$ – the topological signature of internal fragmentation. The cross-network Wasserstein distance $W_\times(\mathrm{Admin},\mathrm{Geo})$ jumps from exactly zero to $737$ at $d=190$~CE, one decade after the Yellow Turban Rebellion, and three long-lived $\beta_1$ cycles matching the Wei, Shu, and Wu domains emerge under the post-184~CE fragmentation model – thirty years before formal partition. Three independent early-warning indicators (Wasserstein velocity $\dot{W}_2$, correlation length $\xi$, and the Integrated Change Tracker) signal collapse onset 45–50~years before formal dissolution.

In quantum programs, Bugs4Q is a widely used benchmark containing real quantum defects. However, its evaluation assumes that benchmark labels remain valid and that generated fixes execute in the target environment. We evaluate two Bugs4Q versions containing 67 unique real Qiskit defects, adding executable tests where missing, and re-run all entries across six pinned Qiskit releases (0.25.0, 0.45.0, 1.0.0, 1.1.1, 2.0.0, and 2.3.1). We find that quantum benchmarks can suffer from silent label inversion: entries become invalid without errors when reference fixes stop executing or buggy programs no longer reproduce failures. Thus, correctness depends on the (benchmark, version) pair rather than the benchmark alone. We evaluate four LLMs (GPT-4o-mini, GPT-5o-mini, GPT-5.4, and GPT-5.4-mini), generating up to 10 repair candidates per defect and testing them across all versions. GPT-5.4 achieves the highest pass@10 (48.8%), followed by GPT-5.4-mini (47.3%), GPT-5o-mini (30.3%), and GPT-4o-mini (22.6%). All models perform best on Qiskit 0.45.0 and decline after the Qiskit 1.0 transition. Many failures arise from deprecated or incompatible APIs rather than incorrect repairs, and 64% of successful repairs occur on entries invalid under the target version. We release a re-validated, version-pinned Bugs4Q benchmark and show that benchmark validation must precede repair evaluation.

Universal machine-learning interatomic potentials provide a promising route for accelerating molecular dynamics simulations of materials, but their transferability to lunar regolith-relevant silicates, oxides, and hydrogen-bearing surface species remains elucidated. Here, we benchmark six foundation models, MACE-MH, MatterSim, SevenNet-0, UPET, UMA, and NequIP-OAM-L, using NVT molecular dynamics simulations of four representative lunar minerals: forsterite, fayalite, ilmenite, and anorthite. Structural fidelity is evaluated using temperature stability, bond-distance statistics, bond-angle distributions, and partial radial distribution functions, with comparison to crystallographic reference data. The models reproduce Si–O, Mg–O, Al–O, and Ca–O local environments reasonably well, while Fe–O and Ti–O coordination environments show broader distributions and larger short-timescale fluctuations, highlighting the need for further validation and fine tuning with additional ground truth data for Fe- and Ti-bearing lunar phases. Hydroxylated surface tests show consistent O–H bond-distance distributions across models and minerals, suggesting that these foundation models may provide useful starting points for screening surface hydroxyl stability and volatile-related processes. Performance benchmarks on a single NVIDIA RTX 4090 show that SevenNet-0, MatterSim, and UPET provide the highest throughput among the six tested models, MACE-MH remains practical at intermediate cost, and UMA and NequIP-OAM-L extend the comparison to newer foundation potentials at higher runtime cost and memory demand. These results provide an initial benchmark for applying universal foundation models to lunar mineral simulations and identify key directions for future ab initio validation, model fine-tuning, and applications to lunar volatile evolution, space weathering, ISRU, and polar sample return studies.

Heliospheric density variations impart delays on pulse times of arrivals from millisecond pulsars. Improper modelling of these variations may affect gravitational wave detection and characterisation by pulsar timing arrays (PTAs). Currently, PTAs typically employ a time-varying, spherically symmetric heliosphere model, which does not capture the full spatial and temporal complexity of the heliosphere. Instead, we investigate whether a three-dimensional, time-dependent model of the inner heliosphere from interplanetary scintillation (IPS) measurements - the IPS-UCSD model - can be employed to mitigate the solar wind in PTA analyses. We applied the IPS-UCSD model to the MeerKAT PTA 4.5-year dataset to assess whether it could correct for heliospheric density variations, and the impact on GW sensitivity compared to a spherically-symmetric model. We find that the model does not accurately correct for heliosphere-induced timing distortions, leading to bias in recovered GW parameters. Using simulations, we show that the spherically symmetric heliosphere model also fails to fully capture heliospheric density variations like those in the IPS-UCSD model. However, if interstellar dispersion measure (DM) variations are also modelled, then the heliospheric model errors are partially absorbed by DM variations, reducing contamination of the GW signal. Therefore we find that a time-varying spherically symmetric model is sufficient to mitigate the effect of heliospheric time delays on recovered GW results at typical PTA radio frequencies, provided other signal components are also modelled. We propose that the most precisely timed pulsars may be used to improve data-driven heliospheric density models in the future.

Materials characterized by competing interactions often exhibit a large number of nearly degenerate periodic states. Here we show that layered UAgBi$_2$ hosts a cascade of field- and temperature-induced magnetic transitions. Based on specific heat, thermal expansion, and neutron diffraction, we construct a phase diagram that reveals at least seven nearly degenerate magnetic states in UAgBi$_2$. The observed multi-step magnetization process can be understood by square-wave structures with distinct propagation vectors $\mathbf{k}$=(0, 0, k) in the presence of strong easy-axis anisotropy that confines the moments along the c axis. Our findings are consistent with a magnetic devil's staircase described by the axial next-nearest neighbor Ising (ANNNI) model and place UAgBi$_2$ as a rare realization of the devil's staircase in a 5f-electron system.

Accurate noise classification is essential for operating near-term quantum processors, yet existing approaches, such as quantum process tomography, scale exponentially with system size, limiting their practicality for routine calibration. We propose a measurement-efficient noise fingerprinting pipeline that combines structured classical shadow tomography with physics-informed feature engineering to identify noise channels from a fixed set of 3-qubit probe circuits. Each sample is represented by a feature vector constructed from randomized Pauli measurements and derived observables designed to resolve physically similar noise channels that produce overlapping signatures under generic measurement sets. We evaluate random forest, extra trees, and a multilayer perceptron on 10,000 labeled samples spanning ten noise models. The three classifiers achieve comparable performance. In the reported runs, random forest and extra trees perform similarly, achieving approximately 0.736 test accuracy and 0.729-0.730 macro F1, compared with 0.715 accuracy and 0.699 macro F1 for the multilayer perceptron. We further analyze the effect of the noise-strength sampling range and conduct a limited sensitivity check using analogous 2- and 4-qubit probes. Confusion analysis shows that readout error, phase flip, thermal relaxation, and bit flip are classified with high reliability, while most remaining errors occur among channels with similar physical effects.

Recovering a noise-amplified inverse quantity from corrupted boundary data is a recurring problem in physics-informed learning for real-world applications. Specifically, small perturbations in the measured field are magnified through the spatial derivatives needed to reconstruct the target, and hence conventional discretization solvers turn them into large unphysical oscillations. We study this problem through the reconstruction of local time-resolved nucleate-boiling heat flux, which cannot be measured directly and must be inferred from infrared surface temperatures by solving an unsteady three-dimensional heat-conduction problem with sharp and rapidly evolving liquid-vapor interface gradients. We show that neither network architecture nor optimizer alone overcomes the spectral bias that smooths away these interface-scale features, and that the two must be addressed jointly. Our approach combines a Chebyshev physics-informed Kolmogorov-Arnold network (PIKAN) backbone, a quasi-second-order (SOAP) optimizer, and a temperature-annealed residual-based resampling scheme that concentrates collocation points at high-residual interface regions. Trained directly on experimental infrared measurements imposed as a boundary condition, the network resolves high-frequency bubble signatures and the high-flux distribution tail much better than a Fourier-feature PINN of equal size and training budget. In particular, it selectively filters measurement noise while preserving the physically meaningful high-frequency features, suppressing the spurious oscillations that contaminate finite-volume reconstructions and yielding more physically consistent heat-flux estimates from noisy experimental data.

We study the variance of the free energy in the Gaussian Sherrington-Kirkpatrick model at zero external field. For every system size and inverse temperature $\beta>0$, we prove $2N^2\operatorname{Var} F_N^{\mathrm{off}}(\beta) \le \log\chi+(\beta^2-1)(\chi-1), \chi=N\mathbb{E}\langle R_{1,2}^2\rangle_\beta$, where $R_{1,2}$ is the replica overlap and $F_N^{\mathrm{off}}=N^{-1}\log Z_N^{\mathrm{off}}$ omits diagonal disorder. The proof uses an exact identity for the edges incident to one spin, Schur complements, and Gaussian disorder interpolation. At criticality the bound reduces to $2N^2\operatorname{Var} F_N^{\mathrm{off}}(1)\le\log\chi$. An explicit nonnegative integral measures its gap. A second decomposition relates this gap to a mixed cubic overlap functional. Existing moment and cavity estimates imply that its required integral is bounded. Critical susceptibility asymptotics give the sharp logarithmic upper coefficient and show that the gap converges exactly when the variance has a constant term. We extend an entropy bound throughout bounded critical temperature windows and establish overlap moment stability on a smaller interval.