In this paper we build upon a previous study in which we demonstrated, using XGBoost and earthquake catalogue data from Japan and Chile, that a set of 60 seismic statistical features (SSFs) had much greater predictive value than a set of 428 generic time series features from the tsfresh package. We here extend this previous work in two key ways, focusing on data from Japan as a large dataset is necessary in order to allow for the training of a deep learning (autoencoder) model. First, we move from whole-region prediction (considering, for each candidate event, the likelihood of an event M $\geq$ 5.0 anywhere in the region in the next 15 days) to localised predictions in which both the region of feature computation and the region of prediction are restricted to a circle of radius 24 km around the candidate event, and we show that performance remains excellent, similar to our previous whole-region study for the same area. Second, we here couple this proven set of SSFs, based on one-dimensional (catalogue) data, with a novel feature based on two-dimensional seismic maps, obtained by training a VQ-VAE model to reproduce such maps as output and identifying a measure of its error in doing so with a localised build-up of crustal stress. We show that while localised prediction based on SSFs can be effective alone, with test AUC values as high as those obtained in the case of Japan in our previous whole-region study, the inclusion of the new natively-spatial VQ-VAE-derived feature, top-ranked by SHAP analysis, can enhance performance and additionally appears to near-wholly replace the traditionally-computed $b$-value in terms of feature usage.

We use the exactly-solvable t Hooft model of 1+1D large-N_c QCD as a rigorous laboratory for the breakdown of analyticity of a causal response function, the meson two-point function. A PT-symmetric deformation i gamma(x-1/2) of the light-cone meson operator, the analogue of an imaginary chemical potential, drives the lowest two mesons to an exceptional point (EP) at gamma_c. Recasting the resolvent as a Jacobi continued fraction yields gamma_c in closed form: 2 pi g^2 N_c at the two-pole level, converging to 7.966 g^2 N_c by depth five -- an analytic, not numerical, threshold. The square-root exponent nu=1/2 is fixed by the 2x2 Jordan form and confirmed by finite-size scaling to N=1999. The breakdown has an unambiguous time-domain signature: the propagator norm is bounded for gamma < gamma_c, grows linearly at gamma_c (the Jordan secular law), and exponentially beyond -- observable, since the deformed operator is a non-Hermitian Wannier-Stark ladder, in photonic and topolectrical analogues. The threshold is locked to confinement, gamma_c propto g^2 N_c, and recurs as a uniform EP cascade; a second, non-reciprocal deformation yields an exactly-exponential non-Hermitian skin effect. This is the first analytically-controlled instance of exceptional-point analyticity breakdown in a confining gauge theory.

We investigate a harmonic interpretation of the hidden flavor coordinates (Q,G,C) previously introduced in a low-rank ternary description of the fermion mass spectrum. The generation coordinate is associated with the odd harmonic mode sequence n_G = (1,3,5), allowing the fermion mass ansatz to be rewritten in a compact harmonic form. The corresponding logarithmic spectrum reveals an additive structure in which the hidden coordinates contribute directly to the observed mass hierarchy. We argue that the projected quantity L = QG + C, which organizes the fermion masses, does not uniquely characterize a fermion state. This motivates the introduction of the full hidden-coordinate vector X = (Q,G,C) and a geometric interpretation of flavor based on coordinate separations and antisymmetric invariants defined within the hidden-coordinate space. The harmonic framework further suggests a possible extension beyond the fermion sector. Combining the fermionic harmonic modes generates the bosonic sequence n_B = (2,4,6,8,10), which exhibits a suggestive correspondence with the electroweak and Higgs scales. Although the resulting framework remains exploratory, it suggests that fermion masses, flavor structure, and bosonic states may reflect different aspects of a common hidden harmonic organization.

We investigate a harmonic interpretation of the hidden flavor coordinates (Q,G,C) introduced previously in a low-rank ternary description of the fermion mass spectrum. In this picture, the generation coordinate is associated with the odd harmonic sequence (1,3,5), allowing the fermion mass formula to be expressed in a compact harmonic form. The logarithmic mass spectrum then acquires an additive structure in which the hidden coordinates contribute directly to the observed hierarchy of fermion masses. We further argue that the scalar quantity (L=QG+C), which successfully organizes the fermion spectrum, does not uniquely identify a fermion state. This observation motivates the introduction of the full hidden-coordinate vector X=(Q,G,C) and a geometric interpretation of flavor in terms of distances, relative orientations, and antisymmetric invariants defined within the hidden-coordinate space. The harmonic framework also suggests a possible extension beyond the fermion sector. Combining the fermionic harmonic modes naturally generates the even sequence (2,4,6,8,10), which exhibits a suggestive correspondence with the electroweak and Higgs scales. While this correspondence remains speculative, it points toward a common harmonic structure underlying both fermionic and bosonic states. Although the framework is exploratory, it indicates that fermion masses, flavor organization, and bosonic excitations may represent different manifestations of a deeper hidden harmonic structure.

We show that the strain-driven semi-Dirac transition in Kekulé-O graphene gives rise to a sequence of anisotropic optical fingerprints associated with band structure reconstruction. Across the transition, optical spectral weight is continuously redistributed among the dominant interband transitions, leading to a pronounced enhancement of the optical anisotropy. Combining numerical four-band calculations with analytical low-energy results, we identify three low-energy fingerprints that emerge with increasing strain: gapped absorption peaks, semi-Dirac critical scaling, and a pronounced van Hove optical resonance. At the semi-Dirac critical point, where the Kekulé gap closes at the $\Gamma$ point, the low-energy optical conductivity is characterized by $\sigma_{xx}(\Omega)\propto\Omega^{1/2}$ and $\sigma_{yy}(\Omega)\propto\Omega^{-1/2}$. Beyond the transition, the semi-Dirac point splits into two anisotropic Dirac cones, accompanied by the emergence of saddle points near the $\Gamma$ point. The resulting saddle-point excitations produce a pronounced van Hove optical resonance at energies well below those of graphene, while the split Dirac cones give rise to an anisotropic constant optical conductivity. We further show that the low-energy optical fingerprints can be traced to the continuous evolution of a dominant optical transition channel driven by strain-induced band reconstruction. Moreover, the fingerprints remain identifiable in the presence of moderate disorder broadening and finite-temperature effects, indicating their potential observability under experimentally realistic conditions.

This manuscript reports the first direct neutron-scattering evidence for long-period helimagnetism in the newly identified 4d-substituted B20 compound Fe0.5Rh0.5Si. By combining SANS with low-field magnetometry, we establish the magnetic modulation, construct a field-temperature phase diagram, and identify a candidate A-phase region supported by an independent structural signature. The work is important beyond this single compound because it expands the family of chiral B20 helimagnets into Rh-substituted materials, where spin-orbit coupling, disorder, and Dzyaloshinskii-Moriya interactions can be tuned. It will interest researchers in chiral magnetism, topological spin textures, magnetic neutron scattering, and quantum materials, and provides a foundation for future studies of emergent magnetic phases and topology-driven phenomena in chemically tuned chiral magnets.

In a polycrystalline microstructure, orientation and dislocation content vary smoothly within grains, and the grain boundaries between them are continuous curves. Electron backscatter diffraction (EBSD) records this continuum on a discrete grid with every subsequent analysis (from indexing to advanced pattern processing) confined to that grid. We introduce neural EBSD, which treats an EBSD scan as a continuous, differentiable four-dimensional field of Kikuchi diffraction intensity (in specimen--detector domain) and then represents it with a coordinate-based neural network. We develop and compare two formulations: a joint formulation that maps all four coordinates to intensity, and a factorized formulation that combines continuous specimen-domain coefficient fields with learned detector-domain basis patterns. Tested on recrystallized and additively manufactured Inconel 718, the factorized formulation shows better accuracy in reconstructing Kikuchi patterns that have map-averaged errors below 1% of the maximum intensity. Beyond reconstruction, it provides full-pattern super-resolution in the specimen frame, continuous querying along arbitrary off-grid paths, as well as spatially continuous boundary and heterogeneity localization from analytical spatial derivatives. Storing the network weights and learned bases in place of the raw patterns in a large dataset offers a 700-fold compression while preserving on-demand access to the full patterns for downstream analyses.

Ferromagnetic metals are characterized by enhanced dissipationless transverse transport responses via the anomalous Hall effect, offering a route towards magnetic sensing and spintronic readout functionalities. In most ferromagnets, the anomalous Hall current is constrained to lie in the plane perpendicular to the magnetization (or applied magnetic field). Recently, it has been recognized that selected symmetries can also permit a Hall response in a traditionally forbidden configuration, where the Hall current lies in the same plane as the magnetization, realizing an in-plane anomalous Hall effect. Reported realizations of this effect, however, are typically much weaker than the conventional Hall response in the same material. Here, through engineering specific crystallographic mirror symmetry-breaking, we realize a strongly enhanced in-plane anomalous Hall response in monoclinic Cr3Te4 with room-temperature ferromagnetism. Remarkably, the in-plane anomalous Hall signal exceeds the out-of-plane response by a factor of five, with which we demonstrate a unique in-plane field and current sensing functionality. Combined with density functional theory calculations, our results establish low-crystalline-symmetry ferromagnets with near-Fermi-level Weyl points as a practical platform for symmetry-engineered Hall responses, and point to a route towards room-temperature, geometry-flexible sensing devices.

The high mobility of current-driven skyrmions in synthetic antiferromagnets (SAFs) is widely explained by the macroscopic suppression of the skyrmion Hall effect through gyrotropic force compensation. This established view, however, overlooks a concurrent and significant reduction in the Gilbert damping parameter {\alpha}, a key factor in the Thiele equation governing skyrmion velocity. Here, we show that this damping attenuation originates from a reconfigured magnon-electron scattering landscape. Using a microscopic s-d model, we demonstrate that the strong antiferromagnetic interlayer Ruderman-Kittel-Kasuya-Yosida (RKKY) exchange coupling in SAFs increases the magnonic gap of skyrmion collective modes, thereby suppressing the thermal magnon population and, consequently, the magnon-electron scattering rate that dominates damping in metallic ferromagnets. Our work establishes a dual-mechanism framework to fully explain the superior kinetics of SAF skyrmions: the macroscopic topological effect rectifies the motion direction, while the microscopic dissipation mechanism reduces the drag. This synergy enables high-speed and efficient motion, providing a fundamental elucidation of the enhanced mobility reported in recent studies such as the work by Pham et al. [Science 384, 307-312 (2024)].

We present a simple universal computational algorithm for computing compositional phase diagrams of rocks and their melts at given temperature and pressure. It makes use of the mathematical concept of the convex hull of a set of points in the space spanned by the composition and the Gibbs free energy. All the complexities of determining the stability or separation of phases, the localization and orientation of tie lines, as well as the determination of characteristic points, curves and surfaces such as the solidus, liquidus, solvus, and the eutectic/peritectic points etc, are taken care of by the algorithm that computes the convex hull, supplemented with an algorithm to physically classify the resulting simplices. For the convex hull computation, the publicly available Qhull package can be used, which is available in SciPy. This makes this method accessible and intuitive for a broad set of scientific and educational applications. Although the method is not practical for systems of a large number of components, it is remarkably stable and efficient for systems of up to four. We present our implementation of the method as a publicly available Python package.

Diffeomorphism invariance is a central feature of general relativity. Without external reference structures, matter and geometry must be specified relationally, with respect to internal subsystems serving as reference frames. In quantum gravity, these reference systems must themselves be treated as quantum, motivating the use of quantum reference frames. In this work, we address how such a relational description could be formulated within linearized quantum gravity. To this purpose, we introduce quantum reference fields, i.e. sets of four dynamical scalar fields whose stress-energy tensors enter the gravitational constraints. These fields extend the notion of quantum reference frames to local field-theoretic reference systems, allowing matter and gravitational degrees of freedom to be described relationally with respect to physical quantum systems. By generalizing the perspective-neutral construction of quantum reference frames, we show that relational, gauge invariant observables admit reduced descriptions in the perspective of each quantum reference field, and we derive the unitary transformations relating them. The resulting unitary maps implement local quantum coordinate changes between different internal perspectives, and act on the linearized gravitational field with an analogous structure to a linearized diffeomorphism, but with the classical gauge parameter replaced by a physical quantum field. Finally, we construct a relational von Neumann-type measurement scheme, showing how the corresponding reduced observables can be accessed operationally from the perspective of a quantum reference field.

The canonical Weyl form for four-dimensional static axisymmetric vacuum metrics is obtained by identifying the area function of the two Killing orbits with a harmonic coordinate on the twodimensional orbit space. This construction is valid in Ricci-flat vacuum, but it is no longer available in Einstein spaces with nonzero cosmological constant. In this paper, we consider the generalized orthogonally transitive static axisymmetric line element and derive the reduced Einstein- $\Lambda$ field equations. We show that the canonical Weyl choice $W=\rho$ is locally admissible if and only if $\Lambda=0$. The Kottler metric gives the simplest explicit example of the resulting equation for the area function. Thus, the statement that "Weyl metrics do not allow $\Lambda \neq 0$ " is precise only when the metric is assumed to be in canonical Weyl coordinates. The issue is not staticity or axisymmetry, but rather the fact that the area function is no longer harmonic.

The lattice QCD calculation of generalized form factors are exploited to determine the subtraction constants through all order dispersion relations of Deeply Virtual Compton Scattering (DVCS). The leading order relation is found to constrain significantly the real part of the Compton Form Factors (CFFs), and the higher order one reduces considerably both the real and imaginary part of CFFs in a global analysis of proton data. This is realized by a synthesis of the DVCS data and LQCD calculations within a neural network framework, whose architecture is specifically designed for a reliable extrapolation to unmeasured kinematic regime. By leveraging dispersion relations beyond leading order, our framework allows for adding higher moments of generalized parton distributions (GPDs) from LQCD into the extraction of CFFs from DVCS data.

Heavy quark expansion theory provides the standard theoretical framework for understanding the lifetimes of weakly decaying heavy-flavor hadrons. Within this framework, the matrix elements of four-quark operators play a crucial role in explaining the lifetime differences among hadrons containing the same heavy quark. In this work, we calculate these matrix elements at leading order using full QCD sum rules, with particular emphasis on deriving the corresponding HQET sum rules by taking the heavy-quark limit. While this limit is straightforward for most contributions, it turns out to be rather nontrivial for certain ones. Numerical analyses show that the results obtained from the two approaches are consistent with each other. We further clarify the origin of the large discrepancies reported in the literature between full QCD sum rule and HQET sum rule results. This work contributes to a deeper understanding of the relationship between the two sum-rule approaches and is expected to facilitate future applications of QCD and HQET sum rules in the study of heavy-flavor hadrons. The findings presented here may be of interest to both practitioners of QCD sum rules and researchers working on effective field theories.

We consider a wide class of $2D$ tight - binding models of solid state physics. These models are, in the most general case, non - homogeneous. The topological invariant ${\cal N}_3$ responsible for the quantization of the Hall conductivity, for the specific case of the integer quantum Hall effect in $2D$, is expressed through the Wigner transformation of the two-point electron Matsubara Green function. We express this invariant as a pairing of the element of the $K^{-1}$ group (generated by the Green function) with the specific element of the cyclic cohomology group $HC^3$. According to a set of local index theorems the values of ${\cal N}_3$ can be shown to be integer for a limited class of tight - binding models.

We investigate how a negative cosmological constant affects the Gauss-Bonnet (GB) scalarization in the Einstein-Maxwell-scalar-Gauss-Bonnet theory with a scalar coupling constant $\eta$ to GB term. We focus on the instability of Reissner-Nordström-AdS (RN-AdS) black holes under a scalar perturbation governed by an effective mass $\mu^2_{\text{eff}}$ sourced by the GB term. Unlike the asymptotically flat spacetime case, the onset of scalarization is not merely determined by $\mu^2_{\text{eff}} < 0$, but it is constrained by the Breitenlohner-Freedman (BF) bound. In case that the BF bound is violated ($\eta>2.25$ with $\Lambda=-0.5$), one may find AdS-tachyoinic instability. We find that for $0<\eta<2.25$, the GB$^+$ scalarization may be performed through spontaneous scalarization, while for $\eta<0$ the GB$^-$ scalarization is found to give the single branch of scalarized AdS black holes. For the GB$^+$ scalarization in $\eta_{th}\le\eta<2.25$ with $\eta_{th}$ threshold instability, we obtain the single branch ($n=0$ fundamental branch) of scalarized AdS black holes, contradicting to infinite branches. Finally, it is observed from Gibbs free energy that a phase transition from scalarized AdS black holes to RNAdS black hole occur natually and it is confirmed to be second-order.

We investigate an empirical low-rank structure underlying the fermion mass spectrum. The construction is based on an integer exponent matrix L=QG+Be, where Q labels shell type, G labels generation, and Be introduces a correction affecting only the first generation. The resulting matrix reproduces the observed hierarchy of fermion masses using a small number of integer parameters. The construction naturally introduces hidden coordinates X=(Q,G,C) associated with each fermion species. We show that fermion masses depend primarily on the projected quantity L, while flavor information appears to require the full hidden-state coordinates. Possible implications for the observed structure of the CKM and PMNS mixing matrices are briefly discussed.

We present a Gaussian-process (GP) surrogate model for the normal-incidence reflectance spectrum of one-dimensional GaAs/Al$_{0.3}$Ga$_{0.7}$ distributed Bragg reflectors (DBRs). A Latin-hypercube dataset of 1500 transfer-matrix-method (TMM) simulations is used to train and evaluate the model. Principal component analysis reduces the spectral output to 26 components; one GP is fitted per component. On a held-out test set the GP achieves RMSE=0.085 and $R^2=0.276$, while a Random Forest baseline reaches RMSE=0.065 and $R^2=0.572$. GP inference is 4.4 ms per spectrum compared with ~308 ms for TMM, yielding a ~70x speedup. Uncertainty calibration shows that the GP 95% prediction band covers 98.9% of test residuals. These results establish a rapid surrogate for DBR design-space exploration.

Neural ordinary differential equations (neural ODEs) have rapidly gained prominence as a powerful and unifying framework for conceptualizing artificial neural networks, elegantly connecting the continuous-time modeling of dynamical systems with the discrete, data-driven paradigm of modern deep learning. Beyond their practical advantages they offer fresh theoretical insights into the training and generalization properties of neural networks. The distinctive feature of this framework is its dual dynamical nature: inference dynamics, which govern the ODE evolution during forward computation, and training dynamics, which control the optimization of model parameters. This makes neural ODEs a particularly well-suited theoretical framework for studying a large variety of settings such as multi-layer neural networks (ResNets for example), autoregressive models (with next-token generation dynamics), generative models, and recurrent neural networks in theoretical neuroscience. In this work, we introduce a theoretically grounded class of models for studying neural ODEs trained via online stochastic gradient descent. We solve the training dynamics of these models via dynamical mean field theory and derive learning curves in the high-dimensional limit.

Family puzzle asks why the Standard Model (SM) features exactly 3 families of quarks and leptons. Motivated by topological constraints, we study 4-dimensional fermionic anomalies with discrete $Z_n$ symmetry, classified by the 5d spin bordism group. We show that only the group-cohomology subclass H$^5(Z_n,U(1))\cong Z_n$ can be canceled by an anomalous $Z_n$-symmetric 4d $Z_n$-gauge topological quantum field theory (TQFT), while beyond-group-cohomology $A_{Z_n} p_1$ involving the Pontryagin class $p_1$ cannot (except $n=2,3$). More generally, we prove that any cocycle $\alpha_d\in$H$^d(Z_n,U(1))$ in odd spacetime dimension $d\ge3$ is trivialised by the symmetry extension $1\to Z_n\to Z_{n^2}\to Z_n\to 1,$ and we construct the corresponding symmetric anomalous boundary TQFT. For $d=5$ and $n=3$, this yields a Spin$\times Z_3$-symmetric 4d $Z_3$-gauge TQFT that cancels the mixed discrete $(\bf B+L)$-gauge-gravitational anomaly of the SM in the absence of 3 "sterile" right-handed neutrinos $\nu_R$. We further analyze a generalized SM with $N_c$ colors and $N_f$ families and argue that missing $N_f$ copies of the $\nu_R$ can be naturally replaced by that 4d anomalous $Spin\times_{Z_2^F} Z_{2 N_f,{{\bf B} + {\bf L}}}$ symmetric $Z_{N_c}$-gauge TQFT under the anomaly cancellation, via an appropriate $Z_{N_c}$-color symmetry extension construction $1\to Z_{N_c}\to Spin\times Z_{N_cN_f}\to Spin\times_{Z_2^F} Z_{2N_f}\to1$ of anomalous topological order. For minimal nonzero positive integers $N_c$ and $N_f$, we find the minimal color extensions: $N_c=3, N_f \ge 3$; $N_c=4, N_f \ge 2$; and $N_c=12, N_f \ge 6$. If we further require that an SM baryon is a fermion so $N_c$ is odd, then $Z_{N_c}=Z($SU$(N_c))$ color center, we prove 3 families and 3 colors, $N_c=N_f=3$, is the unique case that stands out. We also prove that $A_{Z_3}p_1= 0\mod3$ for the mod 3 cohomology class in an appropriate context.

While the positive Grassmannian is deeply understood through the rich combinatorics of plabic graphs and positroid cells, its tropical counterpart, the positive tropical Grassmannian Trop$_{>0}G(k,n)$, has lacked a comparable structural framework for general $k$. Both the global face structure of Trop$_{>0}G(k,n)$ and the internal metric geometry of the tropical linear spaces it parametrizes have remained largely uncharted. This paper develops a systematic algebraic and polyhedral foundation that resolves this gap. The engine of our framework is a fundamental tropical duality, analogous to the duality between cluster variables (or more precisely, their $u$-coordinates) and $\mathbf{g}$-vectors, pairing two families of objects introduced by the first author: the planar basis of tropical Plücker vectors and the planar cross-ratios on the positive configuration space. We prove that this duality links the fan structure of the positive tropical Grassmannian to the noncrossing fan of Santos, Stump, and Welker, yielding a global bijection between integer points of $Trop_{>0}G(k,n)$ and noncrossing tableaux. We then study how this discrete combinatorial data controls the continuous metric geometry of positive tropical linear spaces. We realize the bounded complex of an integer positive tropical linear space as the subdifferential of a central roof function on the hypersimplex, and use this realization to embed it into a dilate of the fundamental alcoved simplex. The dilation factor, and hence the geometric diameter of the complex, is governed by a single invariant, the planar kinematics ($K) weight, which we show equals the number of columns in the associated noncrossing tableau. The results of this work are applied in our parallel work on scaffolds for higher tropical Grassmannians.

Scaffolds are the one-dimensional skeleta of high-dimensional flag simplicial complexes of nonpositive curvature. They generalize the phylogenetic trees of Trop G(2,n) to arbitrary $k$, drawing together SL(k)-web bases, affine buildings, the combinatorics of the positive tropical Grassmannian and low-dimensional topology. We prove that scaffolds model points in all tropical Grassmannians via a $k$-point distance function. In this paper, we study in detail CAT(0) planar graphs, which are positive scaffolds for the tropical Grassmannian of three-planes. CAT(0) planar graphs are directed versions of the diskoids of Fontaine-Kamnitzer-Kuperberg, planar dual to SL(3)-webs. Our main result is the construction of a unique representation of any given integer positive tropical Plucker vector by a normal CAT(0) planar graph. We show that any normal CAT(0) planar graph embeds into the tropical linear space as a Lam-Postnikov membrane, and embeds into the Keel-Tevelev membrane within the affine building. We show that Early's planar basis expansion can be computed directly from the strand combinatorics of the dual web, and connect this expansion to Petersen-Pylyavskyy-Speyer's noncrossing tableaux, explored further in our companion paper.

High-resolution large-eddy simulations of decaying stratified and unstratified homogeneous turbulence are used to understand the mixing of passive scalars in stably stratified flows. Two passive scalar mixing layers, one in the vertical direction and the other in the transverse direction, are a model for a plume that is very large relative to the length scale of the velocity. In the transverse direction, the evolution of the passive scalar is broadly similar in the stratified and unstratified cases, although it does spread slightly faster when stratified. Also, the intensity of the scalar fluctuations is higher in the stratified case, and the turbulent/non-turbulent interface is more intermittent. In the vertical direction, though, the stratified case has almost no mixing because the stratification prevents large-scale stirring. Initially, the stratified passive layer grows until its width is proportional to the vertical integral length of the horizontal velocity, which is itself constrained to maintain the vertical Froude number order one. After this early growth, there is little additional spreading of the passive scalar. Modelling of the stratified scalar flux in the transverse direction is done effectively with a one-constant model if the mean profile is known, and a two-constant model if the profile shape must be assumed. In the latter case, the model is good only if the scalar is in quasi-equilibrium with the velocity field such that the length scale of the scalar can be scaled from the kinetic energy. In this study, the Prandtl number of the active and passive scalars is 0.7. It is anticipated that the reverse buoyancy flux resulting from higher Prandtl numbers will affect the passive scalar mixing.

Photothermal imaging is a powerful noncontact and nondestructive technique for subsurface inspection of composite materials, yet its performance is fundamentally limited by the diffusive and irreversible nature of heat transport, leading to severe image blurring and ambiguous depth interpretation. The concept of virtual waves provides a route to overcome this limitation by linking diffusion fields to propagating wave fields, but existing approaches are largely restricted to idealized impulsive excitation. Here, we propose a generalized virtual-wave photothermal tomography framework that extends the diffusion-to-wave transformation to arbitrary boundary excitations, including pulsed, harmonic, and chirped waveforms. Starting from the heat equation with a general source term, we derive a Fredholm integral mapping between the measured diffusion field and a virtual wave field governed by a wave equation, explicitly enforcing causality and thermodynamic irreversibility. The resulting ill-posed inverse problem is solved using ADMM or truncated SVD, depending on the excitation characteristics. Numerical and experimental results demonstrate that the proposed method converts blurred thermal responses into wave-like fields with clear wavefronts and reflections, enabling improved depth localization and tomographic reconstruction. Experiments on carbon fiber reinforced polymer samples with embedded defects show enhanced contrast, sharper boundaries, and more reliable depth interpretation compared with conventional thermographic techniques. This work establishes a unified and physically grounded framework for wave-based photothermal tomography under realistic excitation conditions.

This manuscript maps secure-supply and criticality risks for quantum technologies deployed in extreme environments, linking upstream critical minerals and materials (CMMs) to downstream system performance, continuity of security, and mission assurance. It adopts a reproducible "Critical Level I" screening method to identify materials whose supply concentration, essentiality, and limited mitigatability can create bottlenecks for quantum deployment. The analysis is structured around two use cases: (i) niobium as a key input for superconducting quantum computing and related manufacturing and toolchain dependencies; and (ii) space-qualified superconducting nanowire single-photon detectors (SNSPDs), alongside adjacent single-photon detector platforms such as SPADs, where radiation, thermal cycling, vibration, and electromagnetic interference can degrade device metrics and, in communications settings, threaten continuity of security. The manuscript further situates these dependencies within U.S.-China strategic competition over critical materials, refining capacity, export controls, and overseas mineral acquisitions, while also connecting them to standards-first governance, post-quantum cryptography migration, and the emerging security logic of quantum networking. It argues that static national critical-minerals lists are insufficient for mission-relevant quantum technology and proposes a dedicated Quantum Criticality and Critical Minerals (QCCM) dashboard as a living decision-support tool for tracking concentration, substitutability, qualification bottlenecks, stockpiling gaps, and geopolitical stress signals across quantum platforms. The paper concludes with implications for substitution, diversification, stockpiling, shielding, qualification-by-design, and standards-aligned governance to support secure, sustained, and mission-relevant quantum deployment.

We construct the generalized Komar charge of generic, non-linear theories of electrodynamics (NLED) in 4 dimensions coupled to Einstein gravity. The contribution of the dimensionful coupling constant present in all these theories is obtained by promoting it to a dynamical field which is forced to be constant on-shell by a Lagrange multiplier. We use this charge to derive a Smarr formula for asymptotically-flat black-hole and soliton solutions of these theories that includes the contribution of the coupling constant. Previously, this contribution had been found using homogeneity arguments. We test our results on a broad class of Einstein--NLED theories and analyze in detail the thermodynamics of the regular Bardeen black hole using the conservation of the generalized Komar charge to understand the regularity of regular black holes inside the event horizon.

The discovery of high-$T_c$ superconductivity in Ruddlesden-Popper nickelates has sparked substantial effort towards understanding unconventional electronic states beyond a traditional cuprate-like $d^9$ configurational ground state. An understanding of the interplay between magnetic ground states and multi-orbital physics is key for establishing a microscopic mechanism for superconductivity. In the bilayer nickelates, spin density wave (SDW) order is a prominent feature in the non-superconducting regime, yet its relation to superconducting pairing remains an open question. Here, we use resonant x-ray scattering to examine the existence of SDW order in superconducting bilayer nickelate thin films La$_2$PrNi$_2$O$_7$ (LPNO). Comparing superconducting and oxygen-deficient LPNO thin films, we find that superconductivity occurs in SDW-free, oxygen-stoichiometric regions, whereas oxygen-deficiency promotes SDW order, indicating phase segregation of SDW and superconductivity. Furthermore, Ni-$L_3$ and O-$K$ edge spectroscopy reveals distinct electronic structures - particularly along the $c$-axis - between the two regions. Our results identify oxygen stoichiometry as a key parameter controlling interlayer coupling and thus the electronic structure of bilayer nickelates. In concert with theory, we propose that a ligand hole primarily resides at the inter-bilayer apical oxygen, forming a robust interlayer five-spin polaron state, which serves as the ground state for superconducting bilayer nickelates.

Metallicity can play a significant role in massive binary evolution through its impact on the opacity within stellar interiors and wind-driven mass loss. In this work, we investigate how the double neutron star (DNS) delay time distribution (DTD) is shaped by the metallicity-dependent evolution of the helium star$-$NS progenitor system. Drawing from insights rooted in single and binary star physics, we argue that at a given metallicity, the stellar radius during the helium main-sequence sets a lower limit on the size of the DNS orbit at birth. We then perform population synthesis with the detailed binary evolution code POSYDON to illustrate the resulting DTD across a range of metallicities. Our results indicate that, independent of the common envelope efficiency and reasonable natal kicks, the majority of DNS mergers across metallicities occur typically no earlier than $\simeq 40\,\rm{Myr}$ after star formation and peaks strongly between $80-250\,\rm{Myr}$. Roughly $15\%$ of DNSs merge within 80 Myr, which may explain $r$-process enrichment in environments with brief star formation histories, while $\gtrsim 20\%$ merge on delay times $>1$Gyr, providing an explanation for short gamma-ray bursts in old, metal-poor galaxies. The shape of the DTD can be complex, with a metallicity-dependent split in the dominant formation channel imprinting a characteristic double-peaked structure. Although ideally oriented natal kicks can produce very short merging DNS, we find that the required kick magnitudes are inconsistent with observations. Our work has implications for assessing the contribution of DNS mergers to $r$-process enrichment and gamma-ray bursts/kilonovae transients across cosmic time.

Real-time dynamics of interacting electrons lies at the interface between quantum mechanics and non-equilibrium physics, governing the microscopic origin of ultrafast phenomena of molecules and nano-materials. Though neural network variational Monte Carlo has achieved unprecedented accuracy for stationary state calculations, its extension to real-time evolution remains challenging. In this work, we introduce the neural basis time-dependent variational Monte Carlo framework, which achieves stable and highly accurate simulations of electron dynamics. By constraining the time evolution to a compact, customized manifold spanned by the neural basis, we effectively bypass instability issues and achieve long-term stable evolution. Moreover, we demonstrate that this framework yields benchmark-quality accuracy in simulating the laser-driven dipole responses of the hydrogen atom and a stretched hydrogen molecule, and accurately extracts the dynamic polarizabilities of helium and beryllium atoms. Our work reveals the vast potential of neural network wavefunctions for accurately describing real-time electron dynamics and establishes a promising new route for first-principles simulations of complex, time-dependent electronic phenomena.

We present a compressed Gaussian likelihood for the Planck CMB low-$\ell$ E-mode polarization data, constructed from the SRoll2 likelihood which provides the tightest constraint on the reionization optical depth $\tau$ to date. The non-Gaussian form of CMB low-$\ell$ TT and EE likelihoods makes them incompatible with Fisher matrix analyses that require an analytic Gaussian $\chi^2$, such as the Fisher-bias formalism and Fisher forecasts. We show that the $\chi^2$ of an offset log-normal likelihood takes a Gaussian form in the log-transformed power spectrum amplitudes, and can therefore serve as a proxy for the true Gaussian likelihood of this variable in Fisher matrix analyses, without any explicit change of variables. Building on this, we compress the SRoll2 likelihood into a small number of piecewise offset log-normal functions and validate it against the full SRoll2 likelihood via MCMC combined with Planck and ACT DR6 data, finding excellent agreement across all $\Lambda$CDM parameters and in extended cosmological models. We further demonstrate that Fisher matrix uncertainty estimates from our compressed likelihood agree well with the full MCMC posteriors. We release our compressed likelihood planck-gaussian-lowl, a lightweight Python package incorporating the compressed low-$\ell$ TT likelihood from previous work, allowing a straightforward incorporation of the Planck CMB low-$\ell$ data into any Gaussian-likelihood-based analysis. The package is publicly available at \href{ this https URL }{ this http URL }.