Papers

This work provides a complete analytical characterization of the transfer- matrix structure associated with the finite Kronig-Penney model consisting of one-dimensional arrays of Dirac delta potentials recently introduced by Figueroa et al. (2025). Although their study identified the emergence of specific transfer-matrix entries and related combinatorial coefficients, a rig- orous derivation of the corresponding closed-form expressions has not yet been established. By expressing the N th power of the unit-cell transfer ma- trix in terms of Chebyshev polynomials of the second kind, we obtain explicit closed-form representations for the global transmission and reflection ampli- tudes. The proposed formulation reveals a previously unrecognized structural correspondence between multiple quantum scattering processes, discrete con- volutional patterns, and hypercomplex combinatorial structures.

We evaluate the transport coefficients, namely the shear viscosity $\eta$ and the spatial diffusion coefficient of heavy quarks $D_s$, within a Quasi-Particle Model (QPM). In particular, for the first time this has been done by exploiting novel lQCD data at $N_f=3+1$. In such a framework, in which the gluons are massive, the interactions among quarks and gluons have been evaluated via the scattering matrices evaluated from tree level Feynman diagrams. As far as the evaluation of $D_s$ is concerned, the Fokker-Planck approximation for the relativistic Boltzmann equation has been employed for the diffusion of both charm and bottom quarks in either a $N_f=3$ and a $N_f=3+1$ bulk. We have developed a dual-component Chapman-Enskog formalism for the ratio $\eta/s$ (being $s$ the entropy density) of a mixture of quarks and gluons. The temperature dependence of the shear viscosity is then compared to the results from a Green-Kubo approach, based on the numerical resolution of the relativistic Boltzmann equation with a stochastic implementation of the collision integral. Finally, using the above results, we compare the strong and weak coupling regimes for the ratio $(2\pi T D_s)/(4\pi \eta/s)$.

The empirical London equations make distinct predictions for a superconductor's longitudinal and transverse electrodynamic response. Conventionally, this framework attributes the Meissner effect to the transverse component, with the longitudinal response predicted to remain unchanged on entering the superconducting state, i.e. a static electric field is screened over the Thomas-Fermi length ($\lambda_{\mathrm{TF}} \sim 1$~Å), just as in the nonsupercondcuting metal. J.~E.~Hirsch~[Phys.~ Rev.~B~69,~214515~(2004)] has developed an alternative formalism, which predicts that the longitudinal screening length should instead be governed by the London penetration depth as the system is cooled below the superconducting transition temperature ($T_{\mathrm{c}}$). Here we use a combination of qPlus atomic force microscopy and scanning tunneling microscopy/spectroscopy of single-crystal Pb(111) at $\sim$~340~mK~ \mbox{($T/T_{\mathrm{c}}\sim0.05$)} in an attempt to detect any modifications in electrostatic screening of the longitudinal tip field upon entering the superconducting phase. We quench superconductivity using a magnetic field of 200 mT normal to the Pb(111) surface. By measuring force-distance curves and local field-emission resonance spectra at the same sample position in the presence and absence of the magnetic field, we constrain the change in screening between the normal and superconducting state to less than $\sim 1 \%$. This is between two to three orders of magnitude smaller than that predicted by Hirsch's theory, and entirely consistent with unmodified Thomas-Fermi screening across the superconducting transition.

Precision spectroscopy in the UV and VUV ranges, including spectroscopy of the thorium-229 nuclear transition (148.4 nm), requires narrow-band sources obtained by frequency multiplication of stabilized lasers. Upon harmonic generation, the radiation intensity drops and the phase noise grows. In this work, both factors are analyzed for two types of primary sources: a continuous-wave single-frequency laser and a femtosecond optical frequency comb. It is shown that in the weak-conversion regime for equal average input powers, the power of the central mode in the spectrum of the Kth harmonic of femtosecond radiation matches the harmonic power of continuous-wave radiation for K=2 and noticeably exceeds it for K>2. Within the first-order dispersion approximation, group-velocity mismatch reduces the total conversion efficiency without affecting the power of the exactly phase-matched central mode. The transformation of the phase noise of an ultrastable laser upon harmonic generation leads to two effects that depend on K: the harmonic linewidth grows linearly, whereas the power fraction in the carrier decreases as a Gaussian function and is determined by the high-frequency noise of the stabilization loop (the servo bumps). Measurements of the phase-noise spectra of a laser stabilized to a Fabry-Perot cavity show that for a typical rms phase excursion of ~100 mrad the carrier loses about half of its power already at the eighth harmonic, while for a non-optimal stabilization-loop gain carrier collapse occurs at the second-third harmonic.

Recently, a soliton mechanism for room-temperature superfluorescence in thin perovskite films has been proposed, with a fundamental soliton predicted to remain stable under LO phonon–exciton interactions. At the same time, superlattice architectures offer a route to enhancing superfluorescence in perovskites. Motivated by recent observations of room-temperature superfluorescence in periodic superlattices of quasi-2D metal-halide perovskites, we extend the 2D nonlocal nonlinear Schrödinger equation describing Wannier exciton–LO phonon interactions to superlattice structures, obtaining a 3D nonlocal nonlinear Schrödinger equation. We show that interlayer tunnelling gives rise to breather dynamics corresponding to a stable fundamental soliton in mixed coordinate–momentum space, with the coordinate parallel to the layers and the momentum perpendicular to them. The breather dynamics originate from miniband formation, which induces a momentum-dependent phase modulation of the soliton. In the absence of interlayer tunnelling, the breather dynamics disappear and the soliton becomes stationary. These results establish a direct connection between interlayer tunnelling, miniband formation and soliton dynamics, suggesting that breather behavior can provide a signature of interlayer tunnelling in quasi-2D perovskite superlattices.

This study examines how a risk-based attribution analysis of European heat wave events under climate change varies when explanatory variables are included in the analysis. Instead of relying solely on temperature statistics, the analysis is conducted while conditioning on large-scale circulation or pre-existing climate anomalies. Using the hot European summers of 2006 and 2007 as examples, we observe several systematic effects. Controlling for the presence of atmospheric blocking explains much of the natural temperature variability and greatly improves the separation of present and pre-industrial distributions in both years. In 2006, the predominant strong blocking raised the expected temperatures, so that, by comparison, the observed anomaly no longer appeared unusually hot, even in a pre-industrial climate. More complex effects occur when the conditions are part of the causal chain of climate change, for example, acting as moderators or mediators. By conditioning on such variables, we may remove part of the climate change signal and thus fundamentally alter the outcome of the attribution study. Using a simplified model we demonstrate why attribution studies with different kinds of conditions can reach different, seemingly contradictory conclusions.

We present high-sensitivity, high-resolution radio observations of J023721.13$-$010528.5 using the upgraded Giant Metrewave Radio Telescope in band-3 (250–500\,MHz) and band-4 (550–950\,MHz), along with MeerKAT (1280\,MHz) and VLA (3\,GHz) survey images. The radio source, hosted by a bright cluster galaxy at redshift $z=0.372$, is a giant radio galaxy with a projected linear size between the outermost hotspots of 1.2~Mpc and is one of the largest $S$-shaped radio sources known. Its radio morphology revealed four pairs of components straddling the radio core, which were also local maxima in profiles of radio flux densities and equipartition energy density measured along the radio lobes. Spatially resolved multi-frequency spectral analysis showed progressively older emission from the inner to the outer components, spanning approximately 4–21 Myr. The high degree of symmetry of the inner three component-pairs with respect to the radio core makes it improbable that these are randomly located knots in the radio jet. Therefore, we present J023721.13$-$010528.5 as the prototype of a new class of radio galaxies with four episodes of jet activity — a quadruple-double radio galaxy. We suggest that giant $S$-shaped radio sources may be among the most promising targets for identifying and studying multi-epoch radio jet activity, since their large linear sizes and jet-axis evolution can spatially separate hotspots from successive episodes, making them easier to detect and analyse.

Interest in axions and axion-like particles has resurged, driven by their role in solving the strong CP problem and their appeal as dark matter candidates. The luminosity of the tip of the red giant branch (TRGB) offers a key observable for probing these particle properties. This work aims to improve existing bounds on the axion-electron coupling by adopting a differential observable that is less sensitive to distance, interstellar extinction, the zero-point of bolometric corrections (BCs), and other systematic uncertainties. We use the bolometric magnitude difference between the TRGB and the RGB bump (RGBB) as a distance-independent constraint, applied to three globular clusters of intermediate-to-high metallicity: NGC 104 (47 Tuc), NGC 362, and NGC 5904 (M5). Using photometric catalogs of RGB stars, we determine V- and I-band magnitudes of both features and convert them to bolometric values. After validating that our stellar models reproduce the observed RGBB luminosity, we perform a maximum likelihood analysis with Monte Carlo simulations to propagate uncertainties and derive new bounds on the coupling. A combined analysis of the three clusters yields a maximum likelihood at $g_{13} = g_{ae}/10^{-13} = 0.8$ and a 95% C.L. upper limit of 1.49. Although slightly less stringent than recent bounds from larger multi-cluster samples, this limit is substantially more robust. Under reasonable mass-loss assumptions, $g_{13} \gtrsim 7.5$ is ruled out, as it predicts the disappearance of the HB and AGB phases routinely observed in globular clusters, a limit more than an order of magnitude stronger than current direct experimental bounds such as XENONnT. We demonstrate the effectiveness of this differential, distance-independent method for constraining physics beyond the Standard Model. Applying it to a wider sample of globular clusters would further refine the constraint on $g_{ae}$.

Understanding a chemical reaction requires mapping a symbolic reactant-product description onto the three-dimensional pathway through which atoms rearrange, yet chemistry benchmarks for large language models (LLMs) largely probe factual knowledge and text-based reasoning. Here we introduce TSBench, a benchmark in which an LLM agent uses structure-editing tools to construct three-dimensional transition-state (TS) guesses verified by an automated quantum-chemical pipeline, yielding a physics-grounded pass/fail verdict. Across 546 evaluations of seven frontier LLMs on 78 elementary reactions, the aggregate success rate rose from 50.4% to 66.8% under diagnosis-driven revision; the best models approached 90% on the simplest reactions, yet performance dropped sharply with mechanistic complexity. Most failed attempts produced locally plausible saddle points whose reaction paths led to the wrong reactant-product pair, revealing local geometric intuition without a robust grasp of the global reaction coordinate. TSBench establishes a mechanism-level yardstick for LLM agents in mechanism-sensitive tasks such as synthesis planning and autonomous experimentation.

Transition metal-based quaternary semiconductors show strong magneto-optical and thermoelectric properties, yet their photovoltaic performance in realistic three-dimensional device architectures remains underexplored. In this work, we investigate a n-ZnSe/p-SrScCu3Se4/p+-WSe2 quaternary chalcogenide heterostructure using three-dimensional finite-element simulations in COMSOL Multiphysics. The model self-consistently couples wavelength-dependent optical generation, drift-diffusion carrier transport, and thermal loss analysis under AM1.5G, 1-sun illumination within a fully coupled opto-electro-thermal framework. The effect of absorber width, acceptor level, and bulk defects on photovoltaic performance, carrier generation, and recombination profile is investigated in this study. Quaternary chalcogenide device produces an open circuit voltage (VOC) of 1.02 V, short-circuit current density (JSC) of 32.472 mA/cm2, fill factor (FF) of 88.212%, and power conversion efficiency (PCE) of 29.217% under optimized conditions. The quantum efficiency (QE) results indicate that the device effectively transforms incident light into charge carriers within the visible spectrum, however absorption and carrier collecting performance diminish in the near-infrared range. The electrothermal simulations indicate modest, spatially non-uniform temperature increases relevant to Joule heating and nonradiative recombination heating within the active layers. Overall, these findings ensure that SrScCu3Se4, a quaternary chalcogenide, is a promising absorber material and offers a strong experimental design consideration for obtaining high-performance, thermally stable three-dimensional photovoltaic device topologies.

We investigate the momentum-space structure of the gauge-invariant gluon energy-momentum tensor (EMT) for spin-$0$ and spin-$\tfrac{1}{2}$ hadrons in the light-front formalism. We parameterize the nonlocal gluon EMT in terms of so-called gluon gravitational transverse-momentum-dependent distributions (gravitational TMDs) and derive their connections to twist-2 and twist-3 gluon TMDs. Moreover, we demonstrate that particular components of the gluon EMT encode information about the average kinetic four-momentum of gluons and the internal mechanical properties of hadrons-such as pressure and shear distributions.

The control and perturbation of quantum phenomena with magnetic fields is an indispensable tool in materials research. Recently, in-situ field tuning was implemented into angle-resolved photoemission spectroscopy (magneto-ARPES), which provides direct momentum and energy-resolved information of the field-dependent electronic structure. However, aberrations of the electron trajectories were shown to be substantial, leading to significant spectral distortions and broadening even in small fields. Here we show that the electronic structure can be recovered from magneto-ARPES spectra with high accuracy while maintaining high momentum resolution even when strong trajectory aberrations are present. We studied Bi$_2$Se$_3$ in a dipole field of a coil using a laser-based ARPES system. The electronic structure was reconstructed in post-processing using detailed electron trajectory simulations. We identify two-dimensional (2D) momentum mapping, a micron beam spot size, and precise numerical field simulations as critical technical requirements for high-resolution magneto-ARPES. We show how circular dichroism can provide additional information about the coupling of the magnetic field to the spin. The experimental achievements and the scaling laws from our simulations provide a road map towards magneto-ARPES in larger fields.

NA61/SHINE is a multi-purpose, fixed-target hadron spectrometer at the CERN SPS. Its research program includes studies of strong interactions, as well as reference measurements for neutrino and cosmic-ray physics. A significant advantage of NA61/SHINE over collider experiments is its extended coverage of phase space available for particle production. This contribution summarizes recent selected results from our strong interaction program. These include rapidity spectra of $K^+$ and $\pi^-$ mesons in Xe+La reactions compared to other collision systems, energy dependence of the scaled $\pi^-$ total yield (the `kink` plot) in Xe+La compared to other collision systems and models, $\phi$(1020) rapidity spectra in Ar+Sc collisions compared to models, $\Lambda$ transverse polarization in p+p reactions, energy dependence of intensive quantities of net-electric charge distribution in Ar+Sc collisions compared to p+p results, as well as an update on the evidence of large violation of isospin symmetry in kaon production — the excess of charged over neutral kaons.

Spin-degenerate antiferromagnets can host hidden unconventional magnetism in their lattice degrees of freedom. We show that coherent phonons activate this magnetism by removing the spin-layer operations that enforce equilibrium band degeneracy without changing the collinear Néel order. The frequency and polarization of a pump electric field select a resonant \(\Gamma\)-point optical phonon and, within a doublet, its coordinate direction. This choice fixes the residual spin-layer symmetry. In monolayer MnPSe$_3$, an \(A_{2u}\) mode produces \(i\)-wave splitting odd in the mass-weighted phonon coordinate $Q$, reversing sign under $Q\to-Q$, whereas two orthogonal directions of the same doubly degenerate \(E_u\) doublet produce \(d\)- and \(s\)-wave splitting at a common resonance. Rotating the in-plane pump field \(\bm E_\parallel\) therefore programs both the spin-splitting texture and the thermoelectric spin current, continuously tuning the response between transverse pure-spin and longitudinal spin-polarized currents. A complete classification of two-dimensional collinear spin layer groups identifies the \(\Gamma\)-point coordinates that remove the degeneracy-enforcing operations and activate such unconventional magnetism.

This paper develops a generalization of Zubarev's nonequilibrium statistical operator method for the case of simultaneous inclusion of additive and nonlocal boundary functionals of trajectories. Using a unified thermodynamic approach, a three-parameter model of nonequilibrium systems is constructed, including the first-passage time, the dwell time above a given level, and the absolute extremum of the process. A correspondence is demonstrated between the maximum information entropy method for trajectories and the Donsker-Varadan large deviation formalism. Using the Doob`s h-transform, it is demonstrated that fixing extremal functionals of history induces efficient non-Markovian transport in the system with dynamic adaptation to historical records. Criteria for the applicability of the developed apparatus in the "large time" domain and the possibilities of its use for optimizing stochastic particle separation in periodic potentials are discussed.

In-situ rapid solidification studies demand measurements of thermal histories with high temporal resolution. We present a simple, effective setup to quantify the cooling response of an uncoated commercial Protochips Fusion MEMS chip in an in-situ scanning transmission electron microscopy (STEM) context. We drive user-defined temperature programs via an arbitrary waveform generator (AWG), while recording the voltage drops across a series shunt to reconstruct chip resistance and temperature at sub-millisecond resolution. We confirm the response times inferred from the current; however, the temperature obtained from the physically linked resistance, $T(R)$, evolves more slowly. Analysis of the maximum cooling step reveals an exponential-like relaxation with time constant $\tau=1.80$ ms, consistent with reported thermal lag constants for fast scanning calorimetry. From the time to reach $95\%$ of the temperature difference $\Delta T$, we measure an average cooling rate of $\approx 7.9\times 10^{4}$ K/s. Robustness checks include repeated $R(T)$ measurements (revealing a modest downward drift approaching an asymptote), a 10 k$\Omega$ test load, and characterization of small off-duty arbitrary waveform generator leakage/offsets. These findings define practical bounds on achievable thermal-path rates when planning in-situ electron microscopy experiments with this chip platform.

We develop a nonperturbative functional renormalization group framework within the LPA' to solve the Wetterich flow equation for the $Z_2$-symmetric real singlet extension of the Standard Model at finite temperature, without a low-order polynomial truncation of the loop corrections to the effective potential, using a physics-informed neural network (PINN) representation. In contrast to conventional truncations based on low-order field expansions, our hybrid tree-level-plus-neural-network ansatz yields a continuous, mesh-free description of the effective potential over the full field and scale range. As a proof of concept, we apply the framework to the finite-temperature effective potential relevant to the electroweak phase transition: one-dimensional field-space slices at two benchmark temperatures, and a two-dimensional reconstruction at T=100 GeV yielding a two-step bounce action. The flow is implemented in a multi-domain setup in scale and field space with derivative matching conditions ensuring smoothness and numerical stability. Gauge and Yukawa sectors are incorporated via independently computed perturbative two-loop running couplings, and anomalous dimensions are included in the flow at the LPA' level. We benchmark the network against resummed perturbation theory and against a grid-based relaxation solver of the same equation. Finally, we introduce a soft consistency constraint that keeps the solution close, in sign and order of magnitude, to perturbation theory across the field-space domain. We find this constraint necessary, rather than merely helpful, for selecting a physically sensible solution of the flow equation. The converged result nevertheless retains a residual dependence on this guidance – through hand-tuned weights and an analytic thermal target – which we identify as the central open problem for mesh-free FRG treatments of this kind.

Hydrogen embrittlement limits the deployment of high-strength steels and advanced alloys in hydrogen infrastructure. Laser shock peening (LSP) is increasingly considered as a mitigation route because it combines deep compressive residual stresses with near-surface microstructural modification. This review critically assesses LSP not as an isolated strengthening treatment, but as a surface layer design strategy governed by coupled stress, hydrogen transport and trapping mechanisms. Evidence from steels, nickel based alloys and additively manufactured materials shows that compressive residual stresses may suppress stress assisted hydrogen transport and delay crack initiation, while LSP-induced nanostructuring, dislocations, twins and interfaces can either redistribute hydrogen beneficially or promote localized plasticity and damage. Reported trends are frequently confounded by hydrogen charging mode, surface roughness, contamination, residual stress depth profiling and limited structure performance correlations. Two design critical gaps are identified: the lack of quantitative links between post-LSP stress/defect architectures and hydrogen assisted fatigue crack growth, and the near absence of impact toughness data after LSP under hydrogen exposure. The review proposes mechanism informed qualification routes combining residual stress mapping, hydrogen characterization, service representative mechanical testing and modelling.

Recent scanning tunneling microscopy experiments have discovered emergent spatially modulated Kondo hybridization wave (KHW) order in the heavy fermion superconductor UTe$_2$ and the artificial Kondo lattice system 1T/1H-TaS$_2$, challenging the conventional paradigm of spatially uniform Kondo hybridization in heavy fermion physics. Here, we develop a microscopic theory for KHW order based on the canonical square-lattice Kondo lattice model within the large-$N$ fermionic mean-field approximation. We systematically identify stable modulated KHW phases and establish their ground-state phase diagram. The prominent $\boldsymbol{Q}=(0,\pi)$ KHW phase yields uniaxial stripe modulation of the Kondo hybridization gap, which faithfully reproduces the spatial modulation pattern observed in UTe$_2$. Moreover, its inherent unit-cell-doubling modulation precisely accounts for the spectroscopic features measured in 1T/1H-TaS$_2$. We further predict a characteristic in-plane conductivity anisotropy that serves as a definitive transport fingerprint to discriminate KHW states with distinct ordering wavevectors. Our work provides a microscopic foundation for the newly observed KHW order and establishes a unified theoretical framework for understanding emergent modulated hybridization phenomena in heavy fermion materials.

Asteroseismic estimates of the magnetic field strength in the radiative interior of red giant stars depend strongly on the internal stellar structure derived from models. Since red giant branch merger products have been shown to be able to possess a different core structure than single stars of the same mass, we investigate how a mass-gain history influences our estimates of an internal magnetic field strength. We construct stellar models with and without a mass-gain event after the onset of the RGB evolutionary phase with masses of $1.1\,M_\odot \le M \le 2\,M_\odot$. First, by assuming a weak magnetic field, we investigate the influence of a mass-gain event on the global sensitivity of the oscillation frequencies to the magnetic field. We find that mass-gain models can be several times more sensitive to the field than single-star models of identical total mass at masses above $1.6\,M_\odot$. Therefore, considering a mass-gain evolutionary history for merger candidates allows a significant correction to the magnetic field strength. In the presence of strong magnetic fields, we also show that the critical field strength needed to suppress mixed dipole modes is significantly lower if a mass-gain event has occurred (for stars with masses $M\gtrsim1.6\,M_\odot$). The massive end of the suppressed stars' distribution is therefore strongly favored by a merger origin. We conclude that properly constraining the stellar evolutionary history is essential when aiming to constrain internal field strength estimates from asteroseismic observations.

We apply transfer learning (TL) to construct data-driven models of inclusive electron-nucleus cross sections. Starting from an ensemble of deep neural networks pretrained on \(^{12}\)C data, we fine-tune the models separately for \(^{3}\)He, \(^{6}\)Li, \(^{16}\)O, \(^{27}\)Al, \(^{40}\)Ca, and \(^{56}\)Fe. The resulting models improve for all targets, marginally so for oxygen, where the carbon baseline is already adequate, although their predictive robustness depends on the amount, coverage, and precision of the available target data. We systematically study how model performance depends on the number of fine-tuned layers, on the fraction and selection of the training data, and on the overlap between the source and target kinematic domains. The layer-wise analysis shows that oxygen requires only shallow adaptation, whereas helium, calcium, and iron require substantially deeper fine-tuning. Lithium represents the least robust case because of its limited dataset, while aluminum demonstrates a strong sensitivity to a small subset of highly constraining measurements. For selected kinematic configurations outside the coverage of the carbon training data, the adapted models remain consistent with the measurements within their estimated uncertainties. Finally, we compare the resulting predictions with those of the phenomenological F1F2 model.

Within finite-temperature effective potential framework, we study the effects of PBHs on vacuum decay, the associated gravitational wave spectrum, and the baryon asymmetry. For the PBHs considered, the Hawking temperatures are below the ambient temperature, and their dominant effect is taken to be the gravitational distortion of the Higgs field configuration. Relative to flat spacetime, the PBH background reduces the vacuum decay exponent, enhances the gravitational wave peak amplitude, and shifts the peak frequency downward. For PBH masses of roughly $10^{11}~{\rm g}-10^{13}~{\rm g}$, the sphaleron energy is reduced, while the small PBH abundance renders the associated washout negligible. Additionally, over roughly the same mass range, PBH-emitted BSM particle decays generate a baryon asymmetry too small to spoil the agreement between the baryon abundances inferred from BBN and CMB.

We present a deconvolution-based framework for testing scale-dependent departures of the late-time matter power spectrum from a fiducial cosmological model using $3\times2$pt measurements. We introduce a free-form scale-dependent modulation $A(k)$ of the fiducial nonlinear matter power spectrum and construct the linear response of binned galaxy-clustering, galaxy-galaxy-lensing, and cosmic-shear spectra to the discretized modulation $A(k)$. The response is evaluated with full-sky, beyond-Limber kernels including density, redshift-space-distortion, gravitational-shear, and intrinsic-alignment contributions. We reconstruct $A(k)$ using a regularized modified Richardson-Lucy algorithm, with weak diffusion in $\ln k$ and selection of the minimum-$\chi^2$ solution along the iteration history. Using Rubin/LSST Year 10-like synthetic data, we find that oscillatory modulations with amplitudes $\gtrsim1\%$ can be recovered over $0.1\lesssim k\lesssim0.5\,{\rm Mpc}^{-1}$, provided the oscillation frequency $f\lesssim10$ on $\log_{10}[k/(0.2\,{\rm Mpc}^{-1})]$. We further introduce a posterior-weighted consistency statistic calibrated with posterior-predictive null mocks, thereby accounting for cosmological and nuisance-parameter uncertainties without relying on Wilks' theorem. The null case is consistent with $A(k)=1$, while a $1\%$ oscillatory modulation is detected at $\sim 2.6\sigma$. These results demonstrate the potential of regularized deconvolution as a model-independent consistency test of the matter power spectrum in future $3\times2$pt surveys.

Quantum backflow refers here to the appearance of a negative Schrödinger current for a state whose momentum support is entirely positive. We ask for the smallest modification of the free Schrödinger current that makes it nonnegative for every such state, while preserving the current of each individual momentum component. We show that the required minimal modification changes the free-particle momentum kernel according to \[ K_{\rm Sch}(p,p')=\frac{p+p'}{2m} \;\longrightarrow\; K_{\min}(p,p')=\frac{\sqrt{pp'}}{m}. \] The resulting current is positive and normalized and therefore defines an arrival-time POVM. Extending the directional no-backflow requirement to states containing both momentum signs forces the cross-sector kernel to vanish, \[ K_{\min}^{+-}=K_{\min}^{-+}=0, \] so that the full current is the sum of two independent directional contributions. The resulting POVM is exactly the Kijowski time-of-arrival POVM, providing a current-based physical motivation for both its directional kernels and their separation. Within the diagonal-preserving pairwise-minimal construction considered here, the result is unique. The construction itself does not impose a first-arrival condition.

The matter power spectrum is one of the primary statistical descriptors of the large-scale distribution of matter in the Universe and provides a powerful probe of cosmic structure formation. Measurements of cosmic microwave background (CMB) lensing offer an integrated view of the matter distribution over a wide range of redshifts, enabling the reconstruction of the underlying matter power spectrum. In this work, we reconstruct the reference linear matter power spectrum $ P_\text{lin}(k,0)$ from the baseline joint CMB lensing measurements of Planck PR4, ACT DR6, and SPT-3G using a covariance-weighted modified Richardson-Lucy(MRL) deconvolution algorithm. The reconstructed spectrum is found to be consistent with the fiducial linear prediction on large scales, while exhibiting a systematic enhancement for $k \gtrsim 0.1\,{\rm Mpc}^{-1}$, where nonlinear gravitational evolution becomes important. To investigate this behavior, we introduce a scale-dependent correction factor, $A(k)$, defined through $P(k)=A(k)\,P_{\rm nl}(k),$ where $P_{\rm nl}(k)$ is the fiducial nonlinear matter power spectrum obtained from 2LPT simulations. The reconstructed correction factor remains consistent with unity within $2\sigma$ confidence over the reconstructed range, indicating that the observed enhancement is well explained by the standard nonlinear evolution of the matter power spectrum. In addition, the reconstruction shows agreement with the fiducial BAO template around the BAO feature at $k\sim(0.04-0.06)\ {\rm Mpc}^{-1}$, indicating that some BAO-scale information survives the lensing projection.

Neutron stars are among the densest objects in the universe, and the mass measurements are crucial to the understanding of their equation of state. Pulsars in tight binaries can be weighed dynamically, but accurate mass estimates are often hampered by uncertainties in orbital inclinations. In this paper, we report on multi-epoch optical monitoring of the pulsar binary, PSR J1048+2339, using the 0.5-m RIFT telescope at Lulin Observatory. Our observations reveal frequent optical flares with eclipses caused by the companion. Using the eclipse duration with archival photometric data and orbital ephemeris in the literature, we constrain the inclination to 78.0+/-1.0 degrees and the pulsar mass to 1.79 (+0.09, -0.08) solar masses. This measurement is among the most precise for any redback system to date, demonstrating a novel way to improve the pulsar mass measures with small aperture optical telescopes. Furthermore, the optical eclipse duration is significantly shorter than that measured in M/GeV gamma-rays, possibly suggesting that a fraction of the eclipsed gamma-ray emission originates from the apex of the intrabinary shock. Based on these constraints, we estimate the magnetic field strength of the companion to be 30-170 G. This is consistent with the high field strength implied by the X-ray orbital modulation observed.

Moiré flat bands enhance localization and interactions through suppressed group velocity, but existing approaches largely target a single physical field because distinct excitations generally require different, finely tuned magic configurations. Here we introduce a flat-band mechanism based on strong diffractive hybridization among moiré-folded bands. Period-mismatched modulations open distinct coupling channels whose hybridization renormalizes the band dispersion. An effective Hamiltonian shows that increasing the diffractive coupling progressively suppresses the group velocity, driving the system toward a flat-band regime without field-specific magic configurations. This coupling-induced mechanism enables band flattening across distinct physical excitations. We demonstrate this mechanism in a single-layer moiré optomechanical crystal, where photonic and phononic flat bands are simultaneously realized, and their localized modes and optomechanical interaction are experimentally observed. Beyond photonic and phononic systems, this mechanism may extend to other wave and quasiparticle platforms, providing a general route to co-localizing and coupling distinct physical fields in moiré systems.

We revisit the almost century-old question of which functional of the local energy best optimizes a trial wave function, a problem of central importance in Variational Monte Carlo (VMC) and, more recently, in Neural-Network VMC (NN-VMC). While variance optimization dates back to the 1930s, the high statistical noise and heavy-tailed local energy distributions inherent to modern neural-network wave functions have renewed interest in this approach. We retrace its long and largely forgotten history here, showing its direct relevance to modern Neural Quantum States (NQS) frameworks. Minimizing the variance (an $L^2$ norm) implicitly assumes a Gaussian local energy distribution: an unjustified assumption. For Coulombic systems, the local energy distribution exhibits $E^{-4}$ power-law tails, causing the Central Limit Theorem to fail for the variance estimator. This instability can be mitigated by robust cost functions: the Mean Absolute Deviation (MAD, an $L^1$ norm), the Cauchy loss, or the $L_{-4}$ functional, which features a tail analytically designed to match the $E^{-4}$ exponent. We benchmark these functionals on $H_2^+$, an exactly solvable system at every internuclear distance, using the Guillemin-Zener wave function across the full potential energy curve. While energy minimization by construction yields the lowest energy, variance minimization is surpassed at every $R$ by alternative functionals: MAD proves superior in the bonding region, while $L_{-4}$ performs best in the dissociation regime.

Ice shelves lose mass primarily by calving, a process controlled by the near-front stress field on timescales that span elastic flexure and viscous creep. We formulate a finite-strain Maxwell model for glacier ice in logarithmic strain space. The Hencky strain of a fixed reference configuration is split additively at the level of rates into elastic and viscous parts; the spring is isotropic Hencky elasticity and the dashpot is a Glen-type power law written on the logarithmic strain rate and its work-conjugate stress. At infinitesimal strain the dashpot coincides with Glen's flow law; the elastic strains in the ice-shelf configurations of this paper remain in that regime. The model is integrated with a midpoint evaluation and a backward-Euler correction of the trial dual, and implemented in a finite-element setting. After a viscoelastic column benchmark, the formulation is applied to an idealised ice tongue, including depth-dependent density and moduli, temperature-dependent fluidity, and cliff geometries with a frontal foot or basal undercutting. The resulting stress fields show how viscoelasticity and front morphology control tension near the terminus.

We explore the possibility of using quasiparticle interference near impurities to extract non-local properties of bands. Focusing on the minimal two-band description of a system with multiple valleys, we show that the local density of states (LDOS) induced by non-magnetic impurities can effectively probe both the Berry curvature and the wavefunction winding, locally in each valley. We analyze gapped models based on Dirac, semi-Dirac, quadratic touching, and higher-order touching energy dispersions, in presence of a point-like potential scatterer. We find that for strong enough impurity potentials the LDOS along a contour around the impurity unambiguously shows the wavefunction winding number, in contrast to the case of gapless Dirac-like dispersions where the winding can be precluded by LDOS oscillations in the radial direction. We also establish a general connection between, on the one hand, the Berry curvature as a function of momentum locally in a valley, and on the other hand, the wavefunction winding number and the energy dispersion parameters, making hence the local Berry curvature directly observable from spectroscopic LDOS information.