Papers

Highly-localized light-matter interactions are necessary for scaling trapped-ion architectures. In hyperfine qubits, counterpropagating beams generate entangling gates by coupling with motion, but this effect is undesirable during single-qubit operations. For that reason, single-qubit gates are traditionally implemented with copropagating beams, and the coexistence of two beam geometries adds hardware and computational overhead. In an effort towards collective performance improvement with minimal overhead, we design and implement pulse-amplitude and dephasing robust dynamically corrected gates using Space Curve Quantum Control (SCQC) and compare them against the constant-amplitude gate implementation. We perform gate set tomography on a four-qubit trapped-ion register, and we discover more than 50% error reduction when robust pulses are used. We find that counterpropagating robust gates often outperform their copropagating counterparts and reach error rates as low as $(3.59 \pm 1.25)\cdot 10^{-3}$, using diamond distance as a metric. This value establishes a laser-driven-gate error reference and is merely an order of magnitude higher than the best reported $\textit{microwave}$ gate on a $\textit{single}$ ion. Additional experiments reveal that robust pulses can effectively suppress non-Markovian errors that grow during runtime. Our work challenges the widely accepted belief that copropagating gates should be preferred for their weak motional coupling and invites the adoption of high-performance robust pulses that suppress multiple noise sources of the trapped-ion error budget.

To achieve a robust valley splitting in transition metal dichalcogenides (TMDs) at zero magnetic field is a challenging and elusive goal for valleytronic and spintronic devices. Therefore, in the current study, using the first principles calculations, we introduce an oxide-driven valleytronic platform by employing a two-dimensional ferromagnetic oxide (V2O3) as a magnetic proximity partner for WSe2. We found that the intrinsic ferromagnetism of V2O3 induces a prominent and spontaneous valley splitting of ~ 10.41 meV in WSe2. This pronounced valley polarization mainly originates from the strong interfacial exchange coupling interaction and charge redistribution mediated by V 3d electrons, coupled with the intrinsic spin-orbit coupling of WSe2. Interestingly, this value is significantly greater than the previously reported value for CrI3/WSe2, which corresponds to an effective magnetic field of ~ 10 T. Besides, we also have a high Curie temperature of 500 K, and an out-of-plane magnetic anisotropy energy (MAE) of 0.31 meV, indicating that this oxide-based heterostructure can also be used for near-room temperature operation. Importantly, under the external electric field with a step of 0.1 eV/Å, the ferromagnetism is preserved and an enhancement in Curie temperature and MAE makes this oxide-based heterostructure more valuable for the next generation valleytronic devices. Therefore, these findings establish a new paradigm for realizing tunable, robust, and magnetic field-free valleytronic and spintronic devices for this oxide-based heterostructure. Moreover, this concept can be generalized to other correlated oxide-based TMD systems, providing a versatile strategy for next-generation quantum and functional materials.

The conventional Floquet engineering scheme synthesizes a given target Hamiltonian with a deterministic temporal periodic driving field. In this work, we introduce the stochastic Floquet engineering scheme that can synthesize an arbitrary non-Hermitian target Hamiltonian using a time-periodic driving field with noisy amplitude. Our method is rooted in the Hermitian dynamics taking noise as a valuable quantum resource with no need for loss or gain in prior. We apply our method to engineer a cavity Hamiltonian with dissipative coupling between Fock states, and to prepare a given quantum state from a generally arbitrary quantum state. The stochastic Floqut engineering also provides a way to generate non-unitary quantum gates, which take advantage in certain tasks compared to unitary quantum computing, without the need for ancillae or state-dependent updating.

In this paper we consider complex scalar field with Mexican hat potential coupled with Gauss-Bonnet scalar resulting in restored U(1) symmetry at the stage of inflation, corresponding to the modern cosmological horizon. In our model, the phase transition takes place during inflation, avoiding large-scale axion isocurvature perturbations. Our model provides strong primordial inhomogeneities on small scales and ultra-light axion-like particle as either a fuzzy dark matter candidate or a candidate for inhomogeneous dark energy. We also study the possibility of black hole formation and gravitational wave background in this scenario. We find that in the case when the symmetry breaking field does not backreact on inflation, black hole production is not feasible. However, under specific conditions, gravitational waves fitting the NANOGrav band can be obtained.

We report photometric and spectroscopic observations of the poorly studied post-AGB candidate IRAS 07506-0345, obtained with the telescopes of the Caucasian Mountain Observatory of SAI MSU in 2023-2026. The star exhibits Cepheid-like variability with a pulsation period of P = 33.68 days. Low-resolution spectra reveal a strong CN molecular band at $\lambda$ 3883, characteristic of carbon-rich post-AGB objects, while H$\alpha$ shows phase-dependent emission and P~Cyg-type profiles, indicating shock waves and mass outflow. Radial velocities are measured from multiple spectral lines. Using period-luminosity-color relations for Type II Cepheids, we estimate a luminosity of $L = 1050\pm250\,L_\odot$. The combined properties - period, amplitude, light-curve morphology, infrared excess, low metallicity, and hydrogen line emissions - securely classify IRAS 07506-0345 as an RV Tau variable.

Addressing the critical trade-off between initial Coulombic efficiency (ICE) and reversible capacity in hard carbon anodes for Na-ion batteries (NIBs), we introduce a novel coupling strategy that combines carbon layer orientation reconstruction with closed-pore construction to produce hard carbon with an ultra-low specific surface area. We demonstrate that the nanographite domains within the hard carbon precursor undergo entropy-driven orientation reconstruction through the synergistic regulation of heteroatom doping and medium-temperature carbonization. This process not only increases interlayer spacing and promotes structural disorder but also enables the formation of dense, closed pores and ultramicropores at domain boundaries via confined atomic migration, while simultaneously encapsulating surface open pores within internal closed ones. Due to this unique pore architecture, our hard carbon exhibits an ultra-low specific surface area of 1.89 m2 g-1 with a markedly higher proportion of closed pores. As a result, our hard carbon achieves a remarkable reversible capacity of 342.3 mAh g-1 at 20 mA g-1, with an exceptional ICE of 90.4% and a dominant plateau capacity of 262.3 mAh g-1 (76.6%) for NIBs. We believe this coupling strategy provides a new paradigm for the structural engineering of high-ICE anode materials in advanced NIBs.

We report the discovery and phase connected-timing solution of a second millisecond binary pulsar, PSR J1717+4308B (M92B), in the globular cluster M92 (NGC 6341) using the Five-hundred-meter Aperture Spherical radio Telescope. This new pulsar, with a spin period of 3.51 ms and a dispersion measure (DM) of 35.29 pc cm$^{-3}$, was discovered through frequency-domain acceleration searches. The timing solution shows that M92B is in a binary system with an orbital period of 2.3 days, an eccentricity of $\simeq 4.8 \times 10^{-4}$, and a minimum companion mass of 0.2 $\,M_\odot$. M92B lies within the cluster core radius in projection, and its negative spin period derivative ($\dot{P}$) is consistent with acceleration in the cluster potential. The measured negative $\dot{P}$ of M92B, together with a DM consistent with that of M92A ($< 0.2\, \rm pc\,cm^{-3}$), confirms that both pulsars are members of the cluster. A Bayesian Markov Chain Monte Carlo analysis based on these two pulsars yields broad constraints on the core structural parameters of M92 that are consistent with $N$-body dynamical modeling. This demonstrates that pulsar timing can provide useful dynamical information in sparse pulsar samples.

Compression and heat release interact intermittently in high-speed reacting shear layers, and whole-field averages can obscure their coupling. We examine this coupling in a supersonic reacting hydrogen–air temporal mixing layer using time-resolved mid-plane slices from a three-dimensional direct numerical simulation. A fixed dilatation threshold identifies connected compression events, and exothermic heat release and mixture-fraction-gradient activity are then conditioned on the evolving event population. The record separates into startup ($t^*<5$), transition ($5\le t^*<20$), and developed ($t^*\ge 20$) regimes, with the developed regime carrying the persistent compression–chemistry interaction. In this regime, compression appears as a population of intermittent events with no single structure dominating the field. Stronger exothermic response is associated with larger maximum-event area, larger event count, greater compression–heat-release overlap, and smaller distance from compression to the most exothermic regions. Scalar-gradient amplification peaks near zero lag relative to compression-area excursions, whereas the strongest exothermic response precedes peak compression coverage by $\Delta t^*\approx -0.85$. These results show that compression organizes chemistry most clearly through event population, overlap, proximity, and lag, providing an event-level description of compression–chemistry coupling in an open supersonic reacting shear layer.

Compressibility and chemical reactions in reacting flows provide source mechanisms for pressure fluctuations whose signatures depend on the flow, source distribution, and acoustic environment. Bounded flows can sustain strong feedback and narrowband tones, whereas boundary-free flows more often exhibit broadband source activity distributed across frequency. Near-field combustion-noise source dynamics are examined in a supersonic reacting hydrogen-air temporal mixing layer using high-fidelity time-resolved direct numerical simulation data. Pressure, heat-release, and dilatation fields are used to identify how localized reacting structures, compressive disturbances, broadband spectral content, and burst-driven temporal organization interact. The results show weak pressure–heat-release coherence concentrated within selected low-frequency bands, with no collapse onto a single dominant mode. Combustion intermittency modulates the near-field pressure response within these bands and is accompanied by burst-driven amplitude modulation and transient trajectory sensitivity, while the overall dynamics remain broadband and bounded. A planar source-radiation-potential projection further shows moderate low-frequency angular bias associated with the heat-release source distribution. Information-theoretic measures indicate that pressure fluctuations share more statistical structure with heat release than with dilatation. The analysis characterizes source-side organization and near-field pressure response in the sampled DNS of a reacting shear layer, providing a basis for subsequent observer-based or acoustic-analogy radiation calculations.

Particle-based Fokker–Planck (FP) models provide an efficient kinetic alternative to direct simulation Monte Carlo (DSMC) in slip and early transitional gas flow regimes, but advanced cubic-FP closures require repeated cell-wise moment evaluation and small dense linear solves. This work develops and validates a GPU-native neural surrogate that replaces the deterministic cubic-FP closure calculation inside the particle simulation loop. The trained weights are evaluated directly with batched CuPy operations, avoiding CPU–GPU transfers during online deployment. The validation emphasizes quantitative evidence: component-level runtime profiles, break-even cost analysis including offline costs, conservation and stability diagnostics, particle-per-cell sensitivity, a direct time-averaged coefficient audit, and covariance-based entropy-proxy fidelity checks. The Couette case is retained as a compact, dimensionless verification problem, while the main internal-flow validation is a 2D lid-driven cavity tested by complete simulation conditions, including unseen moderately rarefied cases at nominal $Kn=0.5$ and $Kn=1.0$. For the hypersonic cylinder, a particle-moment covariance-based entropy-fidelity audit is performed on the front stagnation line and in the cell-centered near-wall gas layer. The same deployed neural $C/\Gamma$ closure used for the cylinder flow fields closely reproduces the equilibrium and Gaussian kinetic entropy profiles over the reported front-line and near-wall gas bins; these profiles are used as a relatively exact-FP/ML-FP audit. The study establishes GPU-native learned closure as a practical route to accelerating cubic-FP rarefied-flow solvers, delivering substantial online speedups while retaining the macroscopic, high-order, and entropy-proxy structure of the reference kinetic model.

The observation of extremely large magnetoresistance in WTe2 has attracted considerable attention towards understanding its underlying origin. With its layered van der Waals structure, the question that remains largely unexplored is whether the three-dimensional anisotropic transport characteristics of WTe2 persists under chemical substitution. Here, we present a systematic angle-dependent magneto-transport study of single-crystalline TaxW1-xTe2 (x = 0, 0.05, 0.1). The results are analysed within a mass anisotropy scaling framework to extract the mass anisotropy parameter {\gamma} as a function of temperature and doping. It is observed that Ta substitution leads to monotonic increase of {\gamma} across all temperatures, indicating a progressive deepening of quasi-two-dimensional Fermi surface character. Ta doping also leads to a substantial improvement in crystalline quality, reflected in a pronounced increase in the residual resistivity ratio. Despite weakening electron-hole compensation, the magnetoresistance rises sharply to ~58,211% at x = 0.1, which is assigned to a substantial enhancement in carrier mobility. Rietveld refinement confirms a systematic c-axis contraction with Ta content, identifying the structural origin of the enhanced anisotropy. The mass anisotropy scaling that holds for x = 0 and x = 0.05 breaks down for x = 0.1, where the angular magneto-resistance anisotropy substantially exceeds single-ellipsoid predictions, pointing to a multi-pocket Fermi surface with distinct anisotropies. Nonlinear Hall resistivity provides independent evidence for the underlying multiband character of transport in this system. These findings demonstrate that Fermi surface anisotropy, carrier compensation, and mobility are independent parameters that can lead to tuneable control of large magnetoresistance in topological semimetal WTe2.

The discovery of the hidden-charm pentaquarks \(P_c(4312)\), \(P_c(4440)\) and \(P_c(4457)\) by the LHCb Collaboration are very likely to identify as the \(\Sigma_c^{(*)}\bar{D}^{(*)}\) molecules. A natural and crucial extension is the existence of excited molecular partners built from a ground-state charmed baryon and a radially excited anti-charmed meson, namely \(\Sigma_c^{(*)}\bar{D}^{(*)}(2S)\) molecules. In a framework of chiral quark model, we systematic study pion-emission decays of such excited molecules into the known ground-state \(P_c\) molecules. Our results show that the decay widths are sensitive to the spin structures and the coupled-channel interferences, i.e., the \(\Sigma_c\bar{D}(2S)/\Sigma_c\bar{D}^*(2S)/\Sigma_c^*\bar{D}^*(2S)[1/2(1/2^-)]\) state decays to \(P_c(4440)\) with a width of several MeV, while the width to \(P_c(4457)\) is suppressed below \(0.3\) MeV due to destructive interference. The pion-emission decay can be the key to unveiling the excited molecular spectrum of hidden-charm pentaquarks and provides decisive experimental signatures. We expect the future experiments such as the LHCb and PANDA can verify our predictions.

We study the numerical solution of electromagnetic scattering by an infinitely long impedance cylinder under oblique incidence. After separation of the axial phase factor, the axial electric and magnetic components satisfy a pair of coupled two-dimensional Helmholtz equations. The Leontovich impedance condition couples these components through tangential derivatives, and the associated boundary integral system contains both logarithmic kernels and principal-value tangential derivative terms. Building on existing coupled integral-equation formulations for oblique-incidence cylinder scattering, we construct a high-order Nystrom implementation based on Kress-type logarithmic kernel decomposition, periodic product quadrature, Fourier differentiation for the tangential derivative contribution, and a block diagonal preconditioner associated with the scalar impedance subproblem. Under uniqueness of the continuous scattering problem and a uniform discrete stability assumption, we formulate a high-order convergence framework for the boundary densities and far-field patterns. Numerical experiments include a manufactured Fourier-Bessel benchmark, a plane-wave circular-cylinder validation, a smooth non-circular boundary test, condition-number and GMRES comparisons, and a variable-impedance scattering-width reduction example in a prescribed backward angular sector. The results indicate that the method provides a stable high-accuracy forward solver for the coupled impedance system, rather than a new physical model.

We use density functional theory to investigate the shift-current response in zincblende III–V (AlP, AlAs, AlSb, GaP, GaAs, InP, InAs, and InSb) and II–VI (ZnS, ZnSe, ZnTe, CdS, CdSe, and CdTe) semiconductors. Our main goal is to identify which material generates the largest shift-current under illumination and to examine the factors influencing this response. We find that aluminum-containing semiconductors, particularly AlSb, exhibit the highest shift-current responses, while CdSe shows the lowest. We analyze the contributions of specific band-to-band transitions to the shift-current in AlSb by selectively summing valence and conduction bands. Additionally, we calculate delocalization indices to investigate the electron delocalization, which correlates with the shift current. Hydrostatic pressure does not enhance the shift current in these materials. These findings have potential applications in optoelectronics and identify the most promising zincblende semiconductors for efficient shift-current generation under visible-light illumination

Passing an exact-clone null gate does not entail passing a matched target-selection utility gate. We call a non-tie preference between exact duplicates dark current. On 102 prespecified fresh RewardBench 2 rows, all four configuration–criterion cells report 0/102 clone preferences. Both neutral utility arms pass, but strict utility lower bounds of .539 and .745 miss the .75 working threshold. Conversely, re-evaluation of the same rows on two additional configurations yields a neutral gpt-oss utility pass with 2/102 clone preferences, leaving low-null behavior uncertified. A separately frozen 485-row extension passes both aggregate working gates under both criteria on one local raw-text configuration, yet strict Precise Instruction Following (Precise IF) alignment is 58/154 (.377). Thus matched null and utility results can diverge, and aggregate passage can coexist with weak subset alignment. Interpretation is conditional on the declared configurations, fixed source mixtures, source-label targets, and study-specific working models. The bounds are marginal, the subset rate is descriptive, and non-certification does not prove a defect.

The usual description of the superposition of two (pure quantum) states is ambiguous, since the binary operation of addition in a Hilbert space does not pass down to the quotient projective space. In the setting of complex projective space this paper gives a new geometrical definition of the superposition of two pure states, viewed as two distinct points in the projective space, as the unique (complex) line on which those two points lie. Using the Erlangen program the geometry appropriate for quantum theory of the projective space is precisely defined. Also this rigorous approach is compared with others.

We show that a symmetry-protected Floquet nullspace can host anomalous many-body eigenstates that are obtained by projecting structured parent states onto an exact zero-quasienergy sector. We demonstrate this in a periodically driven PXP chain with an exponentially large (in system size) protected nullspace. Over the accessible system sizes, special parent states show an exponentially increasing enhancement of their nullspace weight relative to the typical value, even as their absolute overlaps decrease. The resulting Floquet scars can therefore become globally orthogonal to their parents while retaining anomalous correlations inherited from them. We demonstrate this mechanism for two contrasting parents: a locally rotated volume-entangled Ivanov-Motrunich scar and the unentangled Rydberg vacuum. Floquet perturbation theory captures the weak-dressing regime, while exact diagonalization shows persistence into nonperturbative regimes where the Floquet Hamiltonian generically contains increasingly nonlocal terms. Our results identify projection into a protected zero-quasienergy sector as a route to Floquet quantum many-body scars.

Measurement of the optical depth to reionization ($\tau_\mathrm{reio}$) is largely driven by the large-scale EE polarization data of CMB ($\ell<30$). Removing the low-$\ell$ EE data potentially alleviates various cosmological tensions. In this work, we study the effect of the low-$\ell$ EE polarization measurements on the CPL, JBP and BA dark energy parameterizations using CMB data from Planck and ACT DR6, combined with DESI BAO and PantheonPlus compilation of Type Ia supernovae. We find that excluding low-$\ell$ EE data shifts $\tau_\mathrm{reio}$ and $A_s$ to higher values through the unbroken $A_s-\tau_\mathrm{reio}$ degeneracy with a $\sim(1.4-1.8)\sigma$ shift in $A_s$ for $\Lambda$CDM and JBP, and a milder $\sim 1\sigma$ shift for CPL and BA. The equation of state (EOS) for all three parameterizations moves towards the quintessence regime ($w(z) > -1$) upon exclusion of low-$\ell$ EE data, driven primarily by the strengthening of the $w_a-A_s$ and the $w_a-\tau_\mathrm{reio}$ correlations, with a small effect from the correlations of $w_0$ with $A_s$ and $\tau_\mathrm{reio}$. The most prominent effect occurs in JBP, where the EOS lies entirely within the quintessence regime at $1\sigma$ when excluding low-$\ell$ EE data. Model comparison through AIC shows positive evidence in favor of CPL and BA and weak evidence in favor of JBP, robust to the inclusion of low-$\ell$ EE data and CMB data used. DIC model comparison shows strong evidence in favor of CPL and BA when low-$\ell$ EE data is included, and positive evidence when it is excluded. For JBP, we get positive (weak) evidence when including (excluding) low-$\ell$ EE data over $\Lambda$CDM.

Quantum critical points can host symmetry-protected topological edge modes even when the bulk is gapless, giving rise to symmetry-enriched universality classes beyond the conventional Landau–Ginzburg–Wilson paradigm. Here we show that the tricritical Ising (TCI) critical point—described by a paradigmatic conformal field theory (CFT) with emergent supersymmetry—admits a topologically nontrivial, symmetry-enriched realization, which we term the topological TCI. We construct this critical point in the cluster O'Brien–Fendley spin chain by applying a symmetry-protected topological entangler to the original O'Brien–Fendley model. The two realizations therefore share the same bulk TCI CFT. Under open boundary conditions, however, the original model exhibits the free conformal boundary condition, whereas the cluster model exhibits a spontaneously fixed boundary condition: an infinitesimal boundary field can select one of the fixed boundary states, yielding spontaneous boundary magnetization. We further show that symmetry enrichment and boundary renormalization-group flow provide two physically distinct routes to the spontaneously fixed boundary condition. Whereas the free and spontaneously fixed boundary conditions of the original model can be interconverted by tuning a symmetry-preserving boundary term, no such conversion occurs for the cluster model along the boundary deformations studied here, even in the strong-deformation limit. Although they share the same conventional boundary CFT data, including the boundary operator content and boundary $g$-function, the two realizations of the spontaneously fixed boundary condition are distinguished by different time-reversal charges of the disorder field....

Quantum illumination provides a quantum advantage in detecting weakly reflecting objects embedded in a noisy environment, even when environmental noise destroys most of the initial entanglement. We investigate this advantage using Haar-random probe states constrained to symmetry-resolved subspaces. Employing tools from quantum channel discrimination and asymptotic hypothesis testing, we derive the discrimination exponents associated with Haar-random probe ensembles and identify the role of symmetry in determining their performance. We show that typical states drawn from fixed-charge sectors achieve the same asymptotic quantum-illumination advantage as maximally entangled probes. In particular, we show that the effective thermal-noise suppression and the corresponding Chernoff exponent are governed by the dimension of the accessible symmetry sector. Our results reveal that the operational resource underlying quantum illumination can be generalized from fine-tuned structure of a specific probe state to the existence of a large symmetry-protected correlation subspace. These findings establish a direct connection between quantum illumination, symmetry-resolved typicality, and quantum channel discrimination, and demonstrate that near-optimal quantum hypothesis testing resources can emerge naturally from generic many-body quantum states constrained by conservation laws.

Block copolymers self-assemble into ordered nanostructures whose geometry is governed by a competition between interfacial energy and chain conformational entropy. While this competition produces a rich sequence of morphologies, topologically complex “frustrated” phases, such as the primitive cubic network and single networks, incur severe packing penalties and are difficult to access in neutral systems. Here we show that ions functionalized at the termini of one block in an AB diblock copolymer melt introduce a qualitatively new stabilization mechanism. Strong ion correlations drive chain-end association and generate a curvature preference toward the charged domain; the resulting tendency of end-localized ion clusters to adopt compact, curved geometries selectively favors the highly frustrated single-primitive-cubic network ($Pm\bar{3}m$) and single-gyroid network ($I$4$_1$32) over the classical phases, in a region of parameter space with a segregation strength lying below the order-disorder transition of the neutral system. Free energy decomposition reveals that the electrostatic energy, arising almost entirely from beyond-mean-field ion correlations, becomes increasingly negative with increasing interfacial curvature. In the primitive cubic network, pronounced local segregation of ions into the cylindrical struts generates compact curved clusters whose correlation energy gain more than offsets the enhanced packing frustration, so the very geometry that is the source of packing frustration in neutral systems becomes the source of its stability here. Increasing ion size weakens correlations and suppresses the network phases, consistent with experimental observations. Our results establish curvature-selective end-group association as a general principle for accessing frustrated topologies in block copolymer systems.

Understanding how higher-order social structures shape epidemic spreading requires models that couple group interactions with adaptive behavior. We introduce an adaptive simplicial susceptible-infected-susceptible (s-SIS) model on d-uniform hypergraphs, where both node states and hyperedge activity co-evolve in response to local infection pressure. Hyperedges represent group interactions of fixed size and dynamically reduce their activity through a feedback mechanism in highly infected environments. Within this framework, we design two classes of hyperedge-level interventions: (i) risk-driven immunization, combining spontaneous, activity-based isolation with targeted deactivation guided by hyperedge infection pressure, and (ii) structural rewiring, which reconstructs group structures either randomly or via degree-preferential attachment. By extending the microscopic Markov chain approximation to higher-order interactions, we derive analytical conditions for the existence and stability of both endemic and disease-free stationary states. Our analysis shows that adaptive hyperedge feedback can induce discontinuous phase transitions, nonlinear epidemic thresholds, and bistable regimes in which sufficiently high initial prevalence drives the system to a disease-free equilibrium. Extensive Monte Carlo simulations support the theory and confirm that targeted immunization and degree-preferential rewiring substantially suppress epidemic prevalence, outperforming random strategies. These results demonstrate that higher-order interactions and adaptive group-level responses fundamentally reshape epidemic bifurcations and suggest principles for designing effective intervention policies in complex social systems.

A central challenge in mesh-free space–time approximation for time-dependent partial differential equations is to represent evolving temporal scales while keeping residual minimization computationally tractable. Random feature methods simplify this algebraic problem by freezing nonlinear trial functions and fitting only a linear readout, but standard static space–time activations provide no explicit relaxation-scale mechanism, making temporal-scale resolution a finite-dimensional bottleneck in stiff, dispersive, or multi-scale regimes. We introduce liquid random feature methods (L-RFM), which replace static temporal activations by closed-form liquid time-constant responses with sampled relaxation scales. The resulting frozen features form temporally structured local or global trial spaces with analytic space–time derivatives for residual least-squares assembly. A density theorem proves density of the deterministic trial spaces in the continuous space–time function class, and a temporal-rank calculation clarifies the role of sampled relaxation scales. Ablation and finite-feature tests identify the liquid temporal response as the primary source of the observed accuracy improvement. Across stiff reaction–diffusion, nonlinear transport, dispersive, complex-valued, and multidimensional benchmarks, L-RFM improves finite-feature accuracy in regimes where temporal-scale representation controls the approximation. By embedding relaxation scales directly into frozen trial functions, L-RFM provides a route to high-accuracy continuous space–time surrogates for evolutionary PDEs while preserving the simplicity of linear least-squares solvers.

We study topological edge solitons in a nonlinear Su–Schrieffer–Heeger (SSH) lattice subject to parametric driving and linear damping. Starting from a vertically driven pendulum chain, we derive an effective driven–damped nonlinear SSH model and investigate its stationary edge-localized states. Analytical calculations reveal the existence of two phase-locked dissipative edge-soliton families that emerge from the nonlinear continuation of the topological edge mode. Using numerical continuation and spectral stability analysis, we construct the corresponding nonlinear branches and determine their stability properties. We show that parametric driving and damping fundamentally modify the conservative edge-state family by generating two dissipative branches with markedly different stability characteristics: one branch remains predominantly unstable, whereas the other develops substantially larger stability regions and significantly weaker instability growth rates. Direct numerical simulations further demonstrate that the robust branch can remain strongly localized over long time intervals even when weakly unstable. Simulations of the full driven–damped Klein–Gordon pendulum chain confirm the persistence of the edge-localized dynamics predicted by the reduced model. These results identify parametric driving and damping as an effective mechanism for enhancing the robustness and persistence of nonlinear topological localization in active lattice systems.

We calculate the spatial string tension in 2+1 flavour QCD in $(3{+}1)$ dimensions within a temperature range of $[166\,\mathrm{MeV},\,1000\,\mathrm{MeV}]$ using spatial Wilson loops with HYP smearing. We use the Highly Improved Staggered Quark action for fermions and the tree-level Symanzik improved gauge action for gluons at two lattice spacings corresponding to temporal extents $N_\tau = 8$ and $10$. We then compare our results with dimensionally reduced effective theories at high temperatures (EQCD and MQCD) to test the onset of dimensional reduction in QCD.

We study the evaporation and Page curve of charged near-AdS$_2$ black holes coupled to a non-gravitating bath at fixed temperature and chemical potential. The low-energy dynamics is governed by the Schwarzian reparametrization mode together with a $U(1)$ phase mode. We average the boundary energy and the outgoing flux over these two soft modes and obtain corrected balance equations for the temperature and chemical potential. We then use the corrected background to calculate the no-island and island entropies and the Page time shifts. We find that the two soft sectors affect the Page transition in our low-temperature semiclassical regime. The $U(1)$ phase mode correction delays the Page transition, while the Schwarzian correction tends to move it earlier. The total Page time shift is therefore determined by the competition between the Schwarzian and $U(1)$ sectors.

The quantum Hamming bound is the standard finite-length sphere-packing bound for exact correction of arbitrary qubit errors. Whether degeneracy can evade this bound has remained unresolved in full generality for nearly three decades: distinct correctable errors may act identically on the code space, so the usual disjoint-sphere argument breaks down. We prove that every exact binary quantum subspace code with $K>1$ obeys the bound, without assuming either nondegeneracy or additivity. Our proof turns the Li–Xing linear-programming polynomial into an exact intersection count for quaternary Hamming balls. Monotonicity in block length and in ball-center separation then reduces the problem to a local node–edge charging inequality at the shortest admissible length. Thus degeneracy can merge correctable error sectors, but cannot enlarge the finite-length binary Hamming bound.

The dramatic slowdown of dynamics in supercooled liquids is accompanied by a sequence of dynamical crossovers, most notably the transition from high-temperature collision-dominated transport to low-temperature activated structural relaxation. A particularly striking manifestation of this change is the crossover from Rosenfeld excess-entropy scaling to the Adam–Gibbs relation. In this work we develop a theoretical framework based on a configuration-space extension of Zwanzig's entropic-neck picture and combine it with a Mori–Zwanzig memory-function formalism to address anomalies of supercooled liquids. The central idea is that structural relaxation is controlled by the narrowing of configurational pathways connecting metastable basins of the inherent-structure landscape. Starting from coupled slow variables describing intrabasin motion and neck fluctuations, we derive a reduced generalized Langevin description in which elimination of the neck coordinate generates a long-lived memory kernel and naturally leads to entropy-controlled activated dynamics. At high temperatures the neck is broad and readily accessible, yielding Rosenfeld-type transport governed primarily by local structural entropy. Upon cooling, progressive neck constriction produces an increasing entropy deficit, leading to Adam–Gibbs behavior and activated relaxation. Within this picture, fragility acquires a simple geometric interpretation: fragile liquids are characterized by a rapid collapse of the effective configurational neck with decreasing temperature, whereas strong liquids exhibit a much slower evolution of accessible pathways. The framework does not by itself compute the configurational entropy, mismatch penalty, or cooperative length from microscopic interactions; its aim is to provide a dynamical and geometrical interpretation.

We investigate a class of traversable wormhole geometries supported by an effective Casimir source corrected by gravitational memory. The construction is motivated by the fact that a time-dependent gravitational background can leave a permanent positive shift in the vacuum polarization of a quantum field confined to a Casimir cavity. By promoting the plate separation to an effective radial scale in the Morris-Thorne spacetime, we obtain a density profile composed of the usual negative Casimir contribution, proportional to $r^{-4}$, and a positive memory-induced correction, proportional to $r^{-7}$. The corresponding shape function is derived directly from the Einstein equations and satisfies the throat condition by construction. We determine the redshift function from a constant barotropic equation of state together with the requirement of regularity at the throat, which fixes the barotropic parameter in terms of the Casimir and memory coefficients. The flare-out condition defines the admissible range of the memory parameter and separates a Casimir-dominated sector from a phantom-like sector, with the transition point associated with a singular limit of the constant-barotropic description. We analyze the curvature scalar, the embedding structure, the energy conditions, and the Tolman-Oppenheimer-Volkoff equilibrium of the anisotropic matter source. The radial null energy condition is necessarily violated at the throat, while the tangential sector depends sensitively on the redshift gradient. We also examine the shadow radius as a phenomenological diagnostic and show that admissible solutions can overlap the EHT range for M87*. The results indicate that gravitational memory can deform Casimir-supported wormholes by softening the ordinary Casimir contribution, modifying the near-throat geometry, and reshaping the internal stress balance required to sustain traversability.

Switching the bulk Chern number in topological materials is of central importance for the design of topological electronic devices. Motivated by recent observations of integer and fractional quantum anomalous Hall effects in twisted transition metal dichalcogenides (tTMDs), we realize the switching of valley Chern number through sliding and gating in alternately twisted tetralayer (ATT) MoTe$_{2}$. Using large-scale density functional theory (DFT) calculations, we show that the Chern number of the first $K$-valley moiré band evolves from $+1$ to $-1$ under the interlayer sliding. Furthermore, an applied electric field can switch the valley Chern number from $-1$ to $+1$. Based on the developed continuum model, we reveal that these switching behaviors are caused by the sliding- and gate-dependent intralayer moiré potential distributions across the layers. Our results establish ATT MoTe$_{2}$ as a promising platform for engineering moiré band topologies through the design of moiré potentials with sliding in multilayer moiré systems.