Transonic flutter is a detrimental aeroelastic instability that can generate large-amplitude structural oscillations, leading to severe vibration, fatigue damage, reduced operational limits, and potentially catastrophic structural failure. Incoming wake disturbances can further amplify this instability, making it critical to identify the underlying aerodynamic mechanisms responsible for predicting and controlling flutter onset. The underlying flow physics is complex with nonlinear interactions between the wake and the wing, shock motion, shock-induced flow separation, vortex shedding and the wing motion. In this study, we perform high-fidelity direct numerical simulations of a sinusoidally pitching NACA0012 airfoil with an underwing cylinder at various transonic Mach numbers and a Reynolds number of 10,000. Through energy maps, we identify that the addition of the cylinder significantly expands flutter boundaries compared to an airfoil-only system. We extend the force partitioning method to partition the power transferred between the flow and the airfoil for compressible flows. Application of this approach to distinct regions of the flow domain indicates that the gap flow between the wing and the cylinder is the dominant contributor to the energy transfer from flow to the wing. The blockage effects due to the cylinder cause flow acceleration on the wing which further enhances the tendency for flutter. We investigate cylinder placement relative to the airfoil to reveal that flutter is enhanced only when the cylinder is placed upstream of the pivot point on the airfoil. The current study highlights how such partitioning methods can parse force and energy transfer mechanisms in complex, unsteady high-speed flows.

Spontaneous symmetry breaking (SSB) remains poorly understood in thermal convection, but hints may be found from its restoration. We hereby compare the two convection systems: experiments with polymer additives, and simulations with linear friction. We observe the restoration of similar symmetric flows in both these systems. Additionally, restoration coincides with enhanced, time-symmetric velocity-buoyancy correlation, and a sharp drop in the normalized buoyancy-response time. These results indicate buoyancy predominance: velocity is statistically slaved to buoyancy and preferentially remains vertical. The predominance of buoyancy provides a local orientation mechanism, which is necessary for restoring the symmetry of the system. Conversely, this orientation mechanism is lost locally in canonical convective flows, thus SSB naturally occurs in Rayleigh-Bénard convection. Our results suggest that the breaking and restoration of symmetry in thermal convection are both attributable to the competition between advection and buoyancy.

A kinetic theory is developed to describe the electrical conductivity, thermal conductivity, and electrothermal coefficients in warm dense plasmas. It models electron degeneracy using the Uehling-Uhlenbeck equation, diffraction by computing scattering cross sections quantum mechanically, and strong coupling by treating the scattering events using the potential of mean force. A key advancement detailed here is the development of a Chapman-Enskog solution of the Uehling-Uhlenbeck equation for hydrodynamic transport coefficients. The result is a model which accurately predicts transport coefficients spanning from warm dense matter conditions through hot dilute plasmas, including the influence of electron-electron interactions. Results are compared with quantum molecular dynamics simulations, experiments, and other models. The present method is able to capture the ''Spitzer'' terms in the classical plasma limit, while also capturing the correct degenerate limit. The transition between these limits in the warm dense matter regime is explained in terms of the availability of states for electron scattering.

A theoretical model is developed to compute electronic transport coefficients extending from warm and dense to hot and dilute plasma conditions. This kinetic theory-based approach models strong Coulomb correlations by treating interactions using the potential of mean force, electron degeneracy using the Uehling-Uhlenbeck equation, and diffraction by computing cross sections quantum mechanically. The result provides a fast and accurate means to compute electrical conductivity,thermal conductivity and electrothermal coefficients, including contributions from electron-electron interactions. The model enables accurate calculation of materials properties in many warm dense matter systems, including inertial confinement fusion, stellar evolution, and high energy density plasma experiments.

Accurate insights into electric vehicle (EV) driver behavior are essential for long-term infrastructure planning, grid management, and understanding downstream economic impacts, yet individual level data on EV mobility remains limited. Here, we develop a scalable framework to infer EV ownership and charging behavior from passively collected, high-resolution mobility traces covering over 760,000 drivers across four major U.S. metropolitan areas. We identify likely EV drivers based on distinctive visitation patterns to charging stations and gas stations, frequency of visits, and daily travel behavior, and calibrate cohort size using aggregate EV registration statistics. The resulting EV cohort closely matches official registration data at the zip code level and exhibits charging patterns consistent with independent, charger level benchmark datasets, providing external validation of the inferred population. Leveraging this inferred cohort, we reconstruct charging events and associated activity patterns to examine how EV drivers interact with surrounding urban amenities. Compared to non-EV drivers, EV drivers exhibit systematically higher visitation rates to nearby cafes and restaurants during charging sessions, revealing significant economic spillover effects. Furthermore, we find EV drivers exhibit trip bundling behavior, visiting more POIs over less time and distance on days where they charge versus all other days. These patterns are not observable in conventional charging session data, which lack behavioral context beyond the charging event itself. Our results demonstrate the potential of using mobility data to enable a richer, behaviorally grounded understanding of the off-plug needs of EV drivers, providing a foundation for optimizing charging infrastructure deployment and co-locating complementary urban amenities in an increasingly electrified transportation landscape.

Accurate determination of magnetic exchange coupling constants ($J$) from density functional theory (DFT) remains challenging, particularly for open-shell systems where broken-symmetry (BS) solutions suffer from spurious spin contamination that systematically exaggerates $J$ values. Several methods have been proposed to address this problem by adjusting the mapping scheme from the DFT energies to the Heisenberg-Dirac-van Vleck effective spin Hamiltonian energies. In this work, we explore a different route by imposing a constraint to the DFT energy that enforces a target value of the spin-squared expectation, $\langle \hat{S}^2 \rangle$, using a Lagrange multiplier approach. By explicitly controlling the spin character of the electronic state, the method attempts to overcome limitations of standard BS calculations to describe magnetic interactions. As part of the theoretical formulation, we derive analytical expressions for the gradient of the spin-squared expectation value with respect to the spin-resolved density matrices, which are required for the practical implementation of the constraint within a generalized Kohn-Sham scheme. These expressions are general to any single-determinant method and remain valid for arbitrary spin states. We apply the spin-constrained approach to the calculation of $J$ couplings and compare with three energy-difference-based schemes for a set of representative systems, including H$_2$He, H$_3$He$_3$ arranged in an equilateral triangle, and a bis($μ$-hydroxo) Cu(II) complex. Across all cases, the constrained formulation yields systematically lower and more consistent exchange couplings across different density functional approximations. This work establishes a robust and general route for incorporating spin-state constraints into DFT-based studies of magnetic exchange interactions.

For non-resonant radio-frequency (RF) fields, electron heating in sufficiently collisional plasmas can be driven primarily by inverse bremsstrahlung absorption. When the quiver velocity v_osc approaches the electron thermal velocity v_th, theory often predicts sublinear scaling of the heating rate with RF power, indicating saturation. We experimentally test this prediction in ultracold neutral plasmas by finding RF pulses of different amplitude and duration that produce the same electron heating. Despite v_osc being comparable to v_th, we measured no observable saturation. We compare our results to linear response theory (LRT) and a binary collision theory (BCT). The predicted saturation in both theories is sensitive to how common assumptions about cutoff parameters are applied, and agreement with experimental results is much better if quiver-velocity-dependent cutoffs in LRT and BCT are used. Additionally, under our conditions of moderate coupling and magnetization, we find no evidence that RF heating distorts the electron velocity distribution from Maxwell-Boltzmann, indicating saturation from the Langdon effect is suppressed.

Population displacement following environmental shocks reshapes the spatial organization of social interactions, often fragmenting existing ties and weakening community cohesion. Although social capital is widely recognized as a key determinant of resilience, its dynamic restructuring after disruption remains poorly quantified. Here, we develop a spatially embedded, dynamic network framework that operationalizes social capital as a network of repeated encounter opportunities inferred from large-scale mobility data. We construct temporal co-presence networks at third places to track how socio-spatial networks reorganize under disruption. We apply this framework to communities affected by the 2021 Marshall Fire in Colorado. We find that disaster-induced displacement leads to substantial contraction of socio-spatial networks, with mean weighted degree decreasing by 48%. To isolate underlying mechanisms, we develop two counterfactual models: a random node removal model and a behaviour-informed model in which individuals are removed based on their estimated propensity to evacuate. Both counterfactuals predict substantially lower connectivity than observed, indicating that post-disaster connectivity remains systematically higher than expected based on displacement behavior alone. Structural analysis of the network reveals that this residual connectivity is disproportionately concentrated among bonding ties between sociodemographically similar individuals, while bridging ties are comparatively fragile. Furthermore, interaction becomes increasingly located around third places, suggesting that these places act as spatial anchors for the persistence of social ties under disruption. Together, these findings provide a first empirical view of how behavioral responses to disruption shape community resilience through the reorganization of social networks.

Edge-localized modes (ELMs) impose severe transient heat, and particle loads on plasma-facing components, posing a critical challenge for steady-state operation of tokamak fusion reactors. Existing ELM control techniques either rely on externally applied perturbations or operate within narrow parameter windows, raising concerns for reactor scalability. Here we demonstrate that controlled injection of a low-Z impurity can fundamentally modify pedestal transport and stability, enabling access to long ELM-free periods through impurity-driven turbulence. Using boron (B) powder injection in the DIII-D tokamak, we observe a progressive reduction of ELM frequency, culminating in long ELM-free phases. Pedestal stability analysis reveals a pronounced decoupling of peeling and ballooning stability boundaries at moderate B injection levels, opening a stability channel toward super-high confinement operation. At higher injection rates, long (~300 ms) ELM-free periods are achieved. Fluctuation measurements show that B injection selectively enhances low-frequency pedestal turbulence, increasing inter-ELM particle transport and regulating pedestal gradients. The establishment of a feedback loop between turbulence, particle transport, and the resulting modification of pedestal conditions, indicated by the observed hysteresis loop in the evolution of density fluctuations in response to the B injection rate, is presented.

Two-dimensional particle-in-cell simulations of an inductively coupled plasma (ICP) are used to investigate the influence of radio-frequency (RF) current waveform and frequency on plasma characteristics, collision processes, and the electron velocity distribution function driven by asymmetric triangular waveform current.

Rydberg atom-based microwave electric field sensing has attracted growing interest owing to its inherent advantages, such as absolute calibration, wideband operability, and compatibility with room-temperature devices. A critical bottleneck that limits sensitivity is the inefficient coupling between the Rydberg atoms and the incident microwave field, particularly when detecting weak signals propagating in free space. Here we propose and experimentally validate a scheme that integrates a horn antenna with a resonant microwave cavity to significantly improve this coupling for free-space signal reception in the S-band. Using a two-photon excitation scheme in a cesium vapor cell, we systematically characterize the sensing performance under three configurations: a bare cell, direct cavity injection, and a cavity coupled to a horn antenna that captures free-space microwave signals over a 1 m distance. In the antenna-coupled cavity configuration, we achieve an optimal sensitivity of 2.33 nV/cm/$\sqrt{\text{Hz}}$ at the receiving antenna, which corresponds to an enhancement of approximately 17.9 dB compared to the optimized bare vapor cell configuration. Our findings offer a practical and effective route to boost the sensitivity of Rydberg atomic sensors, facilitating their adoption in real-world microwave metrology and wireless communication applications where weak free-space electric fields must be reliably measured.

We investigate the cosmological evolution associated with the quadratic symmetric teleparallel gravity framework, \( f(Q)=Q+αQ^{2}+β\) where the relation \(Q\propto H^{2}\) generates an additional \(H^{4}\) contribution to the Friedmann equation. Using the exact algebraic solution for $H(z)$, we reconstruct the effective dark-energy sector and compare the background evolution with $Λ$CDM using Type Ia supernovae, BAO, and cosmic-chronometer data. At the perturbative level, the model modifies the Poisson equation through a time-dependent effective gravitational coupling $G_{\textrm eff}(z)=G\big[1+\tfrac{2}{3}A E^{2}(z)\big]^{-1}$, where $A=18αH_{0}^{2}$. For $α>0$ this produces a weakened gravitational interaction, suppressing the linear growth factor $D(z)$, the growth rate $f(z)$, and the RSD observable $fσ_{8}(z)$. In the nonlinear regime, the reduced gravitational strength increases the spherical-collapse threshold and suppresses the halo mass function, leading to a lower predicted value of $S_{8}=σ_{8}\sqrt{Ω_{m}/0.3}$. Thus, the quadratic $f(Q)$ extension can reproduce mild deviations from $Λ$CDM at the background level while naturally alleviating the $S_{8}$ tension, offering a viable modified-gravity explanation for recent observational hints of dynamical dark energy.

We present a physics-based framework that runs from fundamental interactions and constants to biospheres, using a sequence of quantitative nonequilibrium thresholds ("gates"). Each gate is an inequality in measurable variables-free-energy flux, reaction-transport rates, replication fidelity, coding capacity, ecological closure, and climate feedback gains. Crucially, the gate vector is anchored in fundamental physics: dimensionless constants, nuclear resonance placements (e.g., the $^{12}$C Hoyle state), statistical mechanics (Landauer's bound $k_BT \ln 2$) fix the energetic, kinetic, information-theoretic margins that propagate through the gates. This anchoring lets us propagate sensitivities of the constants into biosphere-level metrics (net primary productivity (NPP), cycle-closure ratios, and climate feedback gain), yielding an end-to-end map from constants to biospheres. The framework is predictive: it yields testable inequalities, margin rankings, and population-level correlations between stellar and planetary boundary conditions and biosphere feasibility. It does not claim point predictions of life prevalence; rather, it specifies which gate margins are observable-bounded versus prior-dominated under explicitly stated chemistry/solvent families and forward models. Darwinian dynamics (heritable variation under selection) appears mid-pipeline; the end of the pipeline is a planet-scale biosphere capable of sustaining positive NPP, closing elemental cycles over geologic time. Questions of prevalence are secondary; our primary objective is to establish a constructive physics->chemistry->biology->genetics->ecosystems pipeline with testable margins and observables. As a result, we recast abiogenesis and biosphere persistence as a gate vector of falsifiable inequalities and map their margins to exoplanet observables, turning the problem into a phase diagram with explicit, testable slack.

It has recently been shown that x-ray parametric down-conversion (XPDC) provides access to high-energy polaritons, resulting from the hybridization of down-converted photons with electronic excitations in a nonlinear medium. Here, we present a spectrally resolved study of this effect around the K-shell absorption edge in diamond. Our results exhibit pronounced signatures of polaritonic hybridization, which we visualize by introducing a polariton spectral map and analyze by help of theoretical modelling. We find that the hybridization at this absorption edge results in substantially higher coupling strength than previously reported for a non-resonant case and reaches well into the strong-coupling regime. In addition, we demonstrate how our measurements of polaritonic XPDC allow us to extract the refractive index for bulk diamond at high spectral resolution around the carbon K-edge.

In decaying magnetohydrodynamic turbulence, energy can be transported from small to large scales, known as inverse transfer. We explore the mechanism behind this phenomenon using shell-to-shell transfer functions. Independent of magnetic net-helicity, large magnetic scales receive energy directly from the integral scale in both the magnetic and kinetic reservoirs, leading to increasingly non-local transfer for larger receiving scales. The resulting rate of energy increase in each receiving scale is proportional to its energy, resulting in self-similar, multiplicative growth. Even though the system is magnetically dominated, contributions from kinetic-magnetic and magnetic-magnetic energy-exchange are similar in magnitude. In the case of vanishing net-helicity, transfer functions between the positively and negatively helical parts of the field are computed. We find that inverse transfer only occurs within each helical sector, not across them. Our findings are consistent with the theory underlying the conservation of the Hosking integral, which explains inverse transfer as merging of local magnetic islands with equal-signed helicity.

Background in General Relativity (e.g. black holes, wormholes, or spacetime models in general) is needed to comprehend more recent efforts around understanding quantum phenomena like entanglement (e.g. >>It from qubit<< as well as >>ER = EPR<<). The former in turn requires a lot of knowledge from differential topology and differential geometry. While this knowledge is available in very good mathematics textbooks, it is scattered i.e. quite a bunch of sources need to be consulted to acquire it. The goal of this contribution is to provide the major background in a single place; in this sense, this contribution is some sort of guided tour through the corresponding literature.

The discrimination of neutron and gamma pulse shapes is a key technology in fields such as nuclear safety monitoring and radiation assessment. An enhanced recursive gated cyclic residual-sparse linear attention network is developed on the CLYC detector experimental platform to overcome weak noise resistance, limited feature extraction and inferior real-time performance of conventional algorithms. The experimental dataset comprises 19,971 samples, which were pre-processed and stratified for model training and testing. Results indicate that the proposed algorithm achieves a quality factor of 2.2, with a classification accuracy of 98.7% and a recall rate of 99.4%. It achieves an accuracy of 95.1% under the 20 dB low signal-to-noise ratio condition, exhibiting excellent anti-noise ability.With around 2.8 million parameters, the model takes merely 0.05 ms to process a single pulse on GPU, satisfying real-time monitoring and embedded deployment demands.

Within the frame of the GINGER project, aimed at installing an array of large frame ring laser gyroscopes for fundamental physics tests and as part of a geophysics observatory located in the underground laboratory at Gran Sasso, Italy (LNGS-INFN), we are developing a ring laser gyroscope design to reduce spurious rotation of instrumental origin and the ability to extend the cavity perimeter from 1.5 up to 5m, thanks to the implementation of suitable spacers. The new design led to a prototype, called TRIO, with a side length of 1.52 m, conceived as a transportable instrument. The present paper reports on several preliminary measurements of the Earth angular velocity carried out with TRIO. Results have the twofold objective to assess the instrument performance in the present geometrical configuration and to test validity of the design in view of the GINGER project. To this aim, data obtained with TRIO are compared to typical data acquired with other, previously made, gyroscope prototypes, including the large frame GINGERINO already in operation at the Gran Sasso underground site.

Imaging a quantum many-body system requires probes that resolve the coordinates of its constituents in sufficiently large event samples, allowing measurements of correlation functions [1-4]. High-energy nuclear collisions provide this opportunity on the nuclear scale [5], enabling features of colliding ions, such as their deformation, to be probed through particle correlation observables [6, 7]. However, a quantitative extraction of the correlation properties of nuclei from these measurements is still lacking. Here we show that this is possible for the nucleus $^{129}$Xe using Bayesian inference methods. We combine a deformed-rotor description of the colliding nuclei, which encodes the many-body dynamics of constituent neutrons and protons, with hydrodynamic simulations of the ensuing collision evolution. From a combined global analysis of Large Hadron Collider data on Xe-Xe and Pb-Pb collisions, we then infer that the shape of $^{129}$Xe is nearly maximally triaxial, which aligns with mean-field results for xenon isotopes away from shell closure [8, 9]. From this we evaluate two- and three-particle correlations in the nuclear ground state to provide new constraints for \textit{ab initio} methods in nuclear theory. We establish thus collider experiments as a means of quantifying correlations of protons and neutrons arising from residual forces of quantum chromodynamics.

The neutron-skin thickness and electric dipole polarizability are among the most sensitive probes of the symmetry energy at subsaturation densities. Motivated by the tension raised by recent analyses of PREX-II and CREX data within density-functional-based approaches, we perform a unified study of static and dynamical isovector observables within the antisymmetrized molecular dynamics (AMD) framework. Using thirty interaction parameter sets that span different values of the symmetry-energy coefficient $S_0$, slope parameter $L$, and neutron-proton effective-mass splitting $Δm_{np}^*$, we systematically analyze the neutron-skin thicknesses of nuclei from $^{40}$Ca to $^{238}$U together with the electric dipole polarizability $α_D$ of $^{208}$Pb. A combined $χ^2$ analysis of neutron-skin thicknesses and the electric dipole polarizability yields preferred values of $L$ that increase with $S_0$, reflecting the joint constraint from the static and dynamical observables. Furthermore, we identify the density region mainly probed by these observables as 0.019 $\le ρ/ρ_0\le $0.60, where the relative narrowing strength function varies by less than 10% compared to its maximum narrowing strength. The maximum reduction of the uncertainty of $S(ρ)$ occurs at 0.28 $ρ_0$, where the symmetry energy within 1$σ_{post}$ uncertainty is constrained to be $S(0.28ρ_0) = 13.84\pm 1.31$ MeV. These results demonstrate that a unified AMD analysis of neutron-skin systematics and dipole polarizability provides a complementary constraint on the symmetry energy below saturation density.

Neutron cross sections on fission products are relevant to a wide range of applications, including nuclear nonproliferation and forensics, spent-fuel assay, reactor burnup and design, as well as astrophysics. Evaluated nuclear data libraries generally fulfill application needs for isotopes on or near stability, however, for unstable fission products, theoretical descriptions of neutron-induced reactions often constitute the only available source of information. These models often make use of simplified assumptions, leading to unquantified impacts on predicted cross sections. In this work, we discuss possible approaches to addressing these issues, particularly by leveraging machine-learning methods, improved predictive reaction modeling, and experimental data to better constrain model parameters. Our goal is to eventually produce evaluated files for the most-produced nuclei off stability in the fission process of $^{235}$U and submit them to the ENDF/B for consideration in the future ENDF/B-IX.0 release. Here we present the methodology and discuss preliminary results comparing usual simplified approaches with a more realistic one accounting for nuclear deformation.

How is the B(E2;2_1^+ -> 0_1^+) value in an even-even nucleus related to corresponding B(E2;J_i -> J_f) values in a neighbouring odd-mass nucleus? If either neutrons or protons are confined to a single-j orbital and if the nucleon--nucleon interaction conserves seniority, a simple relation between the two properties is obtained, which may differ from what is found in the weak-coupling limit of the core-particle model. This single-j relation is substantially perturbed if several non-degenerate orbitals are considered. An application to recently measured B(E2) values in neutron-deficient tin isotopes is presented.

The STAR experiment has recently reported data on the $\sqrt{\langleΔp_{T,i}Δp_{T,j}\rangle}/\langle\langle p_T\rangle\rangle$ charged hadron correlation in Au+Au reactions from $\sqrt{s_{NN}}=3-200$ GeV. The beam energy dependence of this quantity is non-monotonic, showing a pronounced minimum at $\sqrt{s_{NN}} \approx 7.7$ GeV, while being essentially flat at lower and higher energies. It has been proposed that such a non-monotonicity would be consistent with increased momentum correlations due to a critical point of QCD. In the present work it is shown, using a simplified model, that the observed structure can be consistently explained by the transition from a baryon dominated system to a meson dominated system and is therefore not a good observable for the critical point of QCD.

We investigate the thermalization, chemical equilibration, and hydrodynamization behavior of the far-from-equilibrium, gluon-dominated quark gluon plasma (QGP) produced in Au+Au collisions at $\sqrt{s_{\text{NN}}} = 200$ GeV using the hadronic transport model SMASH extended to simulate partonic interactions. The initial conditions are prepared using the mini-jet model with nuclear parton distribution functions. We first validate the model in a box simulation with the periodic boundary condition to establish indicators for thermalization, chemical equilibration, and hydrodynamization by analyzing energy spectrum and momentum anisotropy. We observe that the additional inelastic channels accelerate thermalization and chemical equilibration compared to the gluon-only scheme. Applying the same framework to the expanding medium, we find that the energy spectrum converges toward the Boltzmann distribution at $t \sim 0.2$ fm while momentum isotropization is achieved at $t \sim 2$ fm, but chemical equilibration is not clearly established even after 5 fm. The Knudsen number rises above unity after $\sim 4$ fm, indicating a breakdown of the hydrodynamic regime at later times consistent with other kinetic theory approaches.

The hypertriton (${}^{3}_Λ\mathrm H$) is the most weakly bound known hypernucleus and one of the most spatially extended quantum halo systems observed in nature. Despite decades of experimental and theoretical effort, its matter radius and $Λ$ separation energy remain incompletely constrained. We demonstrate theoretically that interaction cross-section measurements provide a direct and highly sensitive probe of both quantities. Realistic three-body hypertriton wavefunctions are combined with a coupled-channel Glauber theory incorporating proton, neutron, and hyperon densities together with $ΛN\leftrightarrowΣN$ channel coupling. The resulting interaction cross section changes by about 400 mb across the currently allowed range of $Λ$ separation energies while retaining theoretical uncertainties below approximately 5\%. A Bayesian inversion demonstrates that future interaction cross-section measurements can determine both the hypertriton matter radius and the $Λ$ separation energy with potentially unprecedented precision. These results establish interaction cross sections as a new structural observable for hypernuclear halo physics.

Neutrinoless double $β$-decay (0$νββ$), if observed, would provide unequivocal evidence of physics beyond the Standard Model. $^{48}$Ca is an interesting candidate system to study because it has the largest Q value among all 2$β$ transitions and is also unstable against single $β$-decay. The observation of both $β$ and 2$β$-decay in the same isotope would provide a unique opportunity to benchmark theoretical calculations of $β$ and 2$β$-decay matrix elements and could provide insight on the quenching of the axial vector coupling constant, g$_A$. We performed a precise measurement of the $^{48}$Ca $β$-decay Q value using the TITAN Penning trap mass spectrometer at the TRIUMF facility. This was achieved through cyclotron frequency ratio measurements of $^{48}$Ca$^{+}$/$^{48}$Sc$^{+}$ and $^{48}$Sc$^{+}$/$^{48}$Ti$^{+}$ using the Time-of-Flight Ion Cyclotron Resonance technique. The $^{48}$Ca $β$-decay Q value was determined to be 279.14(50) keV, a factor of 10 more precise than the previous value given in the 2020 Atomic Mass Evaluation [Chin. Phys. C 45, 030003 (2021)]. This Q value was used to determine the $^{48}$Ca $β$-decay partial half-life, with the result $T_{1/2}^β$ = 5.09(5) x 10$^{20}$ ($g_{A}^{-2}$) y. Our $^{48}$Ca $β$-decay half-life was determined to a precision of 1%, a factor of 30 improvement compared to calculations with the previous Q value. Our result is marginally closer to the experimental lower limit $T_{1/2}^β$ > 1.1 x 10$^{20}$ y, but still a factor 5 longer. It is also a factor of 10 longer than the observed 2$νββ$ decay mode with $T_{1/2}^{2νββ} = 5.96^{+1.39}_{-1.08}$ x 10$^{19}$ y. Hence, it could be possible to observe $^{48}$Ca $β$-decay in future experiments, strengthening the potential importance of $^{48}$Ca to benchmark nuclear structure and 2$β$-decay studies.

We study a heat transfer equation in spatial dimensions $n = 1$, $2$, and $3$. A group classification with respect to the functional parameter $k = k(T)$ is done and symmetry algebras are presented. Recursion operators are found in the case $n = 1$ and infinite hierarchies of symmetries are constructed. We also find a number of exact solution in all the three cases.

A structure-preserving splitting integrator is developed for 3D dissipative bi-Hamiltonian/Nambu systems. The integrator uses Strang splitting for conservative and dissipative parts. For Nambu systems, the divergence-free, conservative part is integrated using the energy/volume-preserving Kahan's method, and the dissipative part is integrated by the forward and backward Euler methods. For dissipative bi-Hamiltonian systems, the conservative part is integrated with the energy-preserving average vector field (AVF) method. In both cases, the Hamiltonians of the conservative parts are preserved in the Lorenz, Chen, and Rabinovich systems. The periodic and chaotic solutions are computed accurately by the conservative-dissipative Strang splitting approach.

We introduce temporal matrix scale invariance (tMSI), a mathematical structure for the two-time correlation kernel of a multivariate observable. A kernel $C(t,t')$ satisfies tMSI of order $α$ if $C(kt, kt') = k^{-α}C(t,t')$ for all $k>0$; this condition holds near a tipping point, where the divergence of the coherence time produces temporal scale freedom. By a kernel factorization theorem, every tMSI kernel separates into a power-law envelope $(tt')^{-α/2}$ and a shape function $F(t/t')$ diagonalized by the Mellin transform. This reveals a decoupling of two independent exponents: the dynamical exponent $α$, carried by the envelope, and the spectral relaxation exponent $β$, determined by the eigenvalue decay of the finite-dimensional truncation. Their equality $α= β$ characterizes a simple critical point; their inequality $α\neq β$ is the signature of temporal multicriticality. We provide a classification of tipping points. The Landau quartic coefficient $a_4$ is given exactly by $a_4 = p^2 + q^2 - 2λpq - g^2_{ααβ}Γ(σ_α, σ_β)$, where $λ= 2\sqrt{σ_ασ_β}/(σ_α+σ_β) \in (0, 1]$, $g_{ααβ}$ is the three-point structure constant, and $Γ> 0$ is in explicit closed form. The transition is continuous for $a_4 > 0$, tricritical for $a_4 = 0$, and discontinuous for $a_4 < 0$. The simple critical point $α= β$ is maximally fragile: any nonzero operator mixing drives $a_4 < 0$, placing the synchronized state generically at the edge of catastrophe. The framework yields a matrix-valued early warning diagnostic, computable from a multivariate time series without knowledge of the underlying equations, that classifies an approaching tipping point as recoverable or catastrophic. Applications to epilepsy and acute myocardial infarction are discussed.

Extending recent advances on constructive quantum field theory, we study cumulants of one of the simplest matrix models in the regime of bounded rank. We analyze both ordinary cumulants and scalar cumulants, which arise from the Weingarten calculus and are essential to the topological expansion in quantum field theory. Our results are valid for arbitrarily large positive coupling and provide new instances where techniques such as the variational approach are applied to cu- mulants.