Papers

Following the first observational study of the two-dimensional spatial distribution of stellar specific angular momentum (sAM) in late-type galaxies, we quantify the morpho-kinematic diversity of galaxy simulations using the newly proposed j-types classification. We analyse the stellar sAM surface density (sAMSD) of $\sim$8000 TNG50 stellar discs spanning $0 \leq z \leq 3.5$ and $9.5 \leq \log(M_\star/\mathrm{M}_\odot) \leq 11.2$, selected from the TNG50 MW/M31 parent sample. We characterize their j-substructures using four morpho-kinematic metrics derived from comparisons with the Freeman sAMSD distribution and the Fourier decomposition of the galaxies in the sAMSD space. A Gaussian mixture model with four fully covariant components assigns each galaxy a probability of belonging to one of four j-types. We find that TNG50 discs exhibit a morpho-kinematic diversity consistent with observations, redistributing stellar angular momentum through four dominant j-substructures that evolve with redshift as follows: j-irregulars ($\bar{z}=0.91$), j-spirals ($\bar{z}=0.76$), j-rings ($\bar{z}=0.62$), and j-bars ($\bar{z}=0.39$). The gas fraction and stellar rotational support ($V/\sigma$) drive this evolution: gas-rich galaxies preferentially host j-irregulars and j-spirals, whereas gas-poor systems favour j-rings and j-bars. At fixed gas fraction, higher $V/\sigma$ favours j-spirals and j-rings, respectively. We conclude that there is a canonical pathway for the redistribution of angular momentum within galactic discs undergoing secular evolution in TNG50, accessible only through their morpho-kinematic description. The sAMSD analysis links variations in stellar dynamics to their consequences for mass redistribution, enabling the reconstruction of comprehensive galactic evolutionary histories.

The structure of a porous material, and in particular its spatial variability, is known to control the intrinsic permeability of the system. We investigate how dead-end pores influence the intrinsic permeability of a porous medium beyond their contribution to total pore volume. Dead-end pores are ubiquitous in porous media, yet they are often treated as hydraulically inactive regions whose influence is assumed to be negligible or absorbed into effective-porosity descriptions. We perform pore-scale flow simulations across different dead-end pore structures, including heterogeneous arrangements, controlled granular assemblies, and a minimal single-channel model to study their impact on the system macroscopic permeability. This strategy allows us to isolate the effects of dead-end pore density, depth, and orientation while preserving the transmitting network. We find that dead-end pores can influence intrinsic permeability: increasing the density of dead-end pores along percolating flow paths enhances permeability, whereas pore depth and junction orientation have negligible effects. The observed permeability enhancement originates from localized hydrodynamic interactions at junctions between transmitting and dead-end pores. Based on these results, we propose an effective formulation that relates the density and spatial organization of dead-end pores relative to the transmitting network to macroscopic permeability. Our findings show that dead-end pore architecture provides an additional geometric control on intrinsic permeability beyond porosity and pore-size statistics.

6 pages, 1 figure, 2 tables. Separates the motions superposed in a young star's proper motion, solar reflex, Galactic rotation, the cloud's own space velocity, subgroup motion and internal flow, and asks which of them a field-alignment statistic actually measures. v4: adds a frame-independent bound on the alignment amplitude; adds an independent check of the bulk motion left by the LSR frame against Kounkel et al. (2022) for Orion A North; corrects one reference; journal-neutral formatting.

We introduce the Artificial Intelligence Forecasting System for Direct Observation Prediction (AIFS-DOP). AIFS-DOP is trained on a 40-year harmonized dataset of gridded observations, without using numerical weather prediction (NWP) reanalysis or model data. The resulting model is competitive with ECMWF's Integrated Forecasting System (IFS) when scored on a one year period of forecasts across 2021/2022. This progress on Direct Observation Prediction represents the first time that a data-driven model, trained solely on observations, is competitive with the IFS at medium ranges for several key upper-air and surface headline scores, when verified against observation data.

In the JWST and DESI era, the JWST high-redshift galaxy observations and DESI baryon acoustic oscillation (BAO) measurements severely challenge the standard $\Lambda$CDM model, while the $H_0$ tension becomes increasingly prominent. In this work, we investigate the capability of the early dark energy (EDE) model to alleviate the $H_0$ tension utilizing cosmic microwave background data from Planck, ACT, and SPT, BAO data from DESI, and ultraviolet luminosity function observations from the JWST. Within the canonical axion EDE framework, the CMB+DESI+JWST data significantly increase the $H_0$ value to $71.58\pm1.05\,\mathrm{km\,s^{-1}\,Mpc^{-1}}$, alleviating the $H_0$ tension to the $1.0\sigma$ level. Simultaneously, this model improves the fit to the JWST data and exhibits statistical performance significantly better than the $\Lambda$CDM model, with $\Delta\chi^2_{\mathrm{tot}} = -18.26$ and $\Delta\mathrm{DIC} = -11.89$. Our results highlight the complementary advantages of JWST high-redshift galaxy data alongside early- and late-time observations in testing EDE and alleviating the $H_0$ tension.

We investigate quantum pump depletion and non-Gaussian state generation in doubly pumped Kerr microresonators operating in the intraresonance regime. The pump modes are treated quantum mechanically rather than as undepleted classical amplitudes, allowing pump depletion, back-action, entanglement generation, quadrature fluctuations, and Wigner-function negativity to emerge from the same multimode dynamics. Starting from the Kerr four-wave-mixing selection rule, we distinguish an effective resonant photon-conversion model from the full Kerr Hamiltonian containing self-phase modulation (SPM), cross-phase modulation (XPM), and four-wave mixing (FWM). The reduced model isolates the photon-conversion network responsible for the discrete $\mathbb{Z}_{n+1}$ phase structure, whereas the full model retains operator-valued nonlinear Kerr phases. For the \(n=2\) intraresonance branch, the four-mode reduced initial-value problem with fixed coherent pump phases has a residual \(\mathbb{Z}_3\) symmetry and generates cat-like Wigner structures near the interaction length at which the generated-mode population \(\langle n_1\rangle\) is maximal and the pump population \(\langle n_0\rangle\) is strongly depleted. The resulting states are not the canonical even or odd coherent states of Dodonov, Malkin, and Man'ko, but multicomponent Schrödinger-cat-like states characterized by Wigner negativity, non-Poissonian statistics, pump-mode quadrature squeezing, and large single-mode Schmidt numbers. Comparison of the reduced and full Kerr dynamics shows that uncompensated SPM/XPM-induced phase shearing suppresses the interference fringes and Wigner negativity responsible for the clearest cat-like signatures. These results identify quantum-depleted intraresonance Kerr dynamics as a route to symmetry-organized non-Gaussian states in Kerr resonators.

We develop a block-encoding compiler that treats matrix product operators as compressed, virtual-path linear combination of unitaries programs. The compiler constructs conditional PREP and local SELECT stages directly from a parent matrix product operator, establishing tensor networks as structured quantum intermediate representations that can be efficiently compiled to block-encoded circuits. We apply the construction to real-time evolution in the Heisenberg chain and two perturbed Heisenberg-family models. Across the regimes studied, the compressed, approximately unitary propagator MPOs retain mild bond dimension and LCU normalization. Relative to an LCU that explicitly lists the $\mathcal{O}(N^K)$ Pauli-product branches of an order-K truncated Taylor polynomial, our virtual-transition implementation replaces combinatorial branch enumeration by a circuit complexity scaling as $\mathcal{O}(\alpha_{\rm MPO}N\chi^2)$, approaching $\mathcal{O}(N\chi^2)$ when $\alpha_{\rm MPO}$ remains mild. We numerically characterize how truncation order, bond-dimension budget, and system size affect approximation error, normalization, and compiler cost. These results demonstrate how classically compressed tensor-network representations can serve as quantum compiler intermediate representations for block encoding and opens new avenues to accelerate quantum algorithms.

Sphere packings in circular cylinders have attracted substantial research interest, among which the discovery of chiral helical structures is the most iconic. However, recent experimental results on zebrafish do not match the known packing structures in circular cylinders. To account for the inherent imperfections of biological tubes, we take elliptic cylinders as the canonical deformation of circular cylinders and investigate the densest packings of hard spheres in them using simulation, theory, and experiments. Starting from the chiral structures in circular cylinders, we demonstrate that even a weak cross-sectional deformation can trigger entirely new phases, including ones that either eliminate global chirality or significantly complicate the chiral structures. This reveals the significant effect of cylindrical anisotropy. The new helical phases under anisotropic confinement remain chiral and develop hierarchical periodic structures, which are difficult to obtain by simulations but are predicted by our newly developed theory for helical phases in elliptic cylinders. The theory also predicts double oscillated-chain phases without chirality, which perfectly match the simulations. Our work offers fresh insights into understanding packings in anisotropic cylinders, which will help researchers to design new materials and to understand many living systems.

Establishing a versatile, fast and reliable magnetic memory technology is a giant bottleneck for cryogenic computing since present-day room-temperature solutions either cease to work or consume too much power. The long-term goal of superconducting spintronics has been to overcome this bottleneck by generating magnetic memories with equal-spin triplet supercurrent driven through them to control their magnetization direction. This path has been hampered by the short spin relaxation length and strong anisotropy in ferromagnets. Here we show how the supercurrent driven generation of spin accumulation in a superconductor/magnetic insulator bilayer, together with Gilbert damping of magnetization lead to a motion of magnetic domain walls. This manifests as a local voltage across the wall, which allows its position to be identified. Associated with this voltage and the current, there is Joule power which is dissipated via the Gilbert damping. The power required to maintain domain wall motion is orders of magnitude smaller than in the normal state, where most of the power is wasted in producing the current.

Red blood cells (RBCs) are essential for oxygen transport, and their remarkable ability to undergo significant deformations during flow is a crucial feature for their physiological function. At intermediate shear rates typical of the microcirculation, RBCs can adopt complex, multi-lobed shapes, signifying a dynamic instability. Here we adopt a perturbative theoretical framework of a quasi-spherical RBC under external shear flow to study such shape instabilities. To better capture RBC maturation and enucleation, we first extend the framework to explicitly account for different excess areas between the stress-free and current membrane shapes. We revisit the reduced equations of motion obtained for an ellipsoidally-shaped RBC, and demonstrate the effect of different excess areas and initial orientation on the dynamical trajectories. Then, we introduce additional spatial modes and show that an emerging instability critically depends on the RBC's shear and bending moduli, the internal to external viscosity ratio, and the excess area, mainly through the RBC's membrane tension. We also study the instability-induced saturation of the membrane tension, and the resulting excess area redistribution at long times. The theoretical framework and the emerging picture of the different instabilities provide insights into the emergence of stomatocyte and trilobe shapes exhibited by RBCs under external flow.

Jet production is the dominant high-$p_{\rm T}$ process at hadron colliders and provides a central testing ground for perturbative QCD, parton distribution functions and determinations of the strong coupling. This contribution summarises recent measurements of inclusive-jet, dijet and jet-multiplicity observables presented at DIS2026, with emphasis on the interplay between experimental precision, next-to-next-to-leading-order predictions, non-perturbative and electroweak corrections, and the treatment of correlated systematic uncertainties. Inclusive jet measurements from CMS and ATLAS constrain the gluon distribution at large Bjorken $x$ and enable extractions of $\alpha_s(m_Z)$ compatible with the world average. Dijet measurements provide complementary sensitivity through the dijet invariant mass, rapidity separation and longitudinal boost, while ratios of inclusive jet multiplicities reduce several experimental and PDF uncertainties and directly probe additional QCD radiation. Recent progress in jet-energy calibration, together with new results from RHIC, ALICE and CMS on jet substructure and heavy-quark radiation, illustrates the breadth of current high-$p_{\rm T}$ jet physics and its relevance for Run~3 and future global PDF analyses.

Ancient human beings started "external entropy production" in a late stage of evolution, in addition to the internal entropy production by which energy was dissipated within the body of life, as previously described consistently with the birth of life by maximum entropy production principle. In this paper, the mechanism for development of external entropy production, which is strongly related with use of tools and controlling fire, is theoretically investigated. Archaeological data show that the brain size of ancient human beings started rapid increase around 2.5 million years ago when the usage of tools and control of fire started. It may be natural to assume that the rapid growth of brain size is related to the growth of awareness which helped cooperation with the other human beings for control of fire. Coupled equations for the growth rate of brain including awareness and for growth rate of size of the interacting human beings are analyzed. The external entropy production per one human being which is directly related to the group size of cooperating human beings is estimated to increase as about 20 million years in the beginning from the critical time. This evolution created coexistence of internal entropy production of traditional multi-cellular life and new external entropy production of multi-body life. A psychological problem due to the coexistence of two kinds of entropy production mechanism in human being and concept of technologies based on the present thermodynamic evolution theory are discussed. It is suggested that the evolutionary understanding of the origin of global warming based on the external entropy production may be important to create an useful countermeasure.

The Large Hadron electron Collider (LHeC) would add a high-current Energy Recovery Linac to the HL-LHC, delivering electron-proton collisions at centre-of-mass energies around the TeV scale. This contribution summarises the QCD and parton-distribution-function (PDF) aspects of the recent LHeC bridge-project study. The combination of high luminosity, a very large lever arm in Bjorken $x$ and $Q^2$, and clean neutral- and charged-current deep-inelastic scattering measurements would enable a coherent determination of all proton PDFs in a single experiment. The resulting constraints would substantially reduce uncertainties in the gluon, valence, strange and heavy-flavour distributions, provide stringent tests of perturbative and small-$x$ QCD, and improve the parton luminosities that enter precision and discovery measurements at the HL-LHC and at future hadron colliders. The same programme gives competitive and complementary determinations of the strong coupling and weak mixing angle, including measurements of its running over a wide range of scales.

(Abridged) We compare the radial abundance gradients of O, Ne, Cl, and Ar using a sample of 42 HII regions and 176 planetary nebulae (PNe) from the DESIRED catalogue in the Galactic disk, comprising the highest-quality observations currently available and presenting the first gradient analysis for this dataset. For all objects, two sets of chemical abundances were compiled: one derived from collisionally excited lines (CELs) and another incorporating the temperature fluctuation parameter (t^2). Oxygen abundances were corrected for dust depletion, and HII region results were compared with Cepheid stars, which trace the present-day interstellar medium. PNe distances were compiled from recent literature, excluding bulge or halo objects to ensure a disk-only sample. All gradients are statistically significant (p < 0.05), except for Cl and Ar in HII regions. The O/H gradients from HII regions and Cepheids are consistent when t^2 is included, underscoring the importance of accounting for temperature inhomogeneities in nebular analyses. The O and Ne gradients traced by older objects are flatter than the present-day gradient by -0.028 +- 0.008 dex kpc-1 on average from both RLs and CELs. This could indicate a temporal steepening of the Galactic abundance gradient; however, this behavior is not reproduced by chemical evolution models, suggesting additional physical processes are at play. The most plausible explanation is that our PNe sample has been strongly affected by radial migration. Under this interpretation, the PNe gradient cannot reliably trace past abundance gradients, but provides a valuable constraint on radial stellar migration, offering important input for chemo-dynamical models of the Galactic disk and for hydrodynamical simulations.

We present GPU algorithms for Ewald summation methods for accelerating N-body Stokes flow problems in periodic domains. Like most N-body codes, Ewald sums use a near-field/far-field decomposition. The near field involves particle-to-particle (P2P) interactions. The far field primarily involves particle-to-grid (P2G) and grid-to-particle (G2P) interactions, as well as Fast Fourier Transforms. For each interaction, we investigate several algorithmic variants. Our implementation uses PyKokkos, a Python interface for the Kokkos C++ parallel programming framework, which supports portability to AMD/NVIDIA GPU and ARM/x86 CPU architectures. Double and single-precision numerical results, alongside analytical performance models, confirm the efficiency of our algorithms on AMD and NVIDIA GPU and on ARM and AMD CPU architectures. The P2P interaction achieves around 73% compute efficiency on NVIDIA H200, 84% on NVIDIA A100, 60% on AMD MI300, 52% on Grace CPU, and 68% on AMD Epyc CPU. A straightforward implementation of the P2G kernel can become a computational bottleneck. We introduce a novel P2G algorithm that achieves up to 16$\times$ speedup compared to a baseline GPU implementation. The overall Ewald sum code processes approximately 8 million particles per second on a H200 GPU, and about a half-million particles per second on a Grace CPU, for nine digits of accuracy. We also perform a multi-GPU weak scaling test on up to 256 million particles (64 GPUs) that shows bounded communication cost for all stages except the all-to-all particle sorting, which can be reduced to neighbor communication in the relevant time-stepping regime.

The formation and global spatial distribution of photochemically produced haze particles remain a key process in exoplanet atmospheres for understanding their observed properties. We aim to develop a flexible haze particle formation and evolution model suitable for time-dependent exoplanet atmosphere simulations. Inspired by recent 2D photochemical modelling efforts, we include a simple activation timescale mechanism to emulate a delayed formation of solid haze particles. We couple our new microphysical haze formation scheme, mini-haze, to the Exo-FMS general circulation model (GCM) and simulate an idealised HD 189733b case study to examine the 3D spatial distribution and sizes of haze particles. Our results suggest that for our chosen haze formation efficiency, particles do not grow beyond $\sim$30 nm, in line with previous detailed 1D modelling. We find the haze spatial distribution follows the vertical velocity structure of the atmosphere, with equatorial convergence patterns of material deeper in the atmosphere at $\sim$10$^{-2}$ bar. The resulting global distribution leads to enhanced haze opacity at the east and west limbs of the atmosphere. In our test cases, radiative feedback from haze opacity can strongly affect the temperature-pressure structures in the upper atmosphere depending on the production rate. Our synthetic spectra results suggest that longer haze-production timescales give rise to stronger haze opacity effects on the observed transmission spectra compared to short-timescale dayside formation, but the stronger thermal feedback from nightside formation leads to an overall larger dayside emission flux. Our current simulations represent a step towards investigating self-consistent haze formation and evolution with chemical feedback effects in 3D, and can be readily applied to other objects of interest, such as sub-Neptune atmospheres.

We show that Gauss-Bonnet black branes in five-dimensional anti-de Sitter gravity are unstable when the Gauss-Bonnet coupling falls outside the range allowed by the conformal collider bounds. The unstable modes and the boundary causality violating modes are connected by a phase rotation of complex boundary momentum.

Io's tenuous atmosphere consists primarily of sulphur dioxide (SO$_2$) with observed column densities of approximately $10^{16}{-}10^{17}$ cm$^{-2}$. However, it remains uncertain whether the sublimation of SO$_2$ surface frost or volcanic outgassing is the primary source of the SO$_2$ atmosphere. In this study, we produce a 2D model of Io's SO$_2$ atmosphere using the Direct Simulation Monte Carlo (DSMC) method. For this purpose, we conduct a literature review on thermophysical parameters of Io's SO$_2$ surface frost to refine the surface temperature model in accordance with the most recent observations, which enables accurate modelling of Io's sublimated atmosphere. We find that the thermal conductivity, which shifts the peak temperature and SO$_2$ column density away from the subsolar point, has a pronounced effect on sublimation-driven winds and interactions with volcanic plumes. Furthermore, a background atmosphere could reduce sublimation-driven winds in Io's atmosphere, while the SO$_2$ column and number densities are not substantially altered. Moreover, we study the influence of the eclipse, when Io passes through Jupiter's shadow, finding that it reduces the average column density on the sub-Jovian hemisphere by a factor of ${\sim}$5.5 in relation to the anti-Jovian hemisphere. We also investigate the interaction of the sublimated atmosphere with a medium-sized plume at various locations relative to the subsolar point. We find a strong influence, especially on the dayside, where the atmosphere is enhanced with material being displaced by the plume, most pronounced when the plume is positioned near the point of maximum sublimation in the early afternoon.

The increasing sensitivity of modern astronomical instruments requires optical fiber connections with high crossmating stability and insertion loss as low as 1% (0.05 dB). Conventional connectors, though suitable for telecommunications, introduce excess attenuation, Fresnel reflections, and alignment instabilities that degrade throughput and calibration accuracy in astronomy. This work presents the design and characterization of ultra-low-loss optical multi-fiber connectors developed for astronomical use. Fabricated using femtosecond-laser 3-D printing, they achieve sub-micron ferrule tolerances. Preliminary metrology shows excellent hole alignment and roundness, and initial throughput tests for three simultaneously connected fibers show losses as low as 0.95% (0.04 dB). Further throughput and FRD characterization to be implemented to assess efficiency, stability, and repeatability under observatory conditions.

We study the $I^G(J^{PC})=0^+(1^{++})$ $K\bar K\pi$ system in an infinite-volume three-body unitary framework, focusing on the pole content of the region of the $f_1(1285)$ and $f_1(1420)$ resonances. The coupled $\pi a_0$-$K\bar K^*$ amplitude is constructed in the spectator-isobar representation, where the one-particle-exchange interaction required by three-body unitarity automatically incorporates the triangle-singularity mechanism. The short-range three-body interaction is constrained by fitting the $0^+(1^{++})$ component of the BESIII $K^0_SK^0_S\pi^0$ invariant-mass distribution in the $J/\psi\to\gamma(K^0_SK^0_S\pi^0)$ decay. Analytically continuing the fitted amplitude to the relevant unphysical Riemann sheets, we find two robust poles: \begin{align} \sqrt{s_{f_1(1285)}}&= \left(1277\pm2\pm1\right) -\mathrm{i}\left(12\pm1\pm0\right)\text{MeV}\,,\notag\\ \sqrt{s_{f_1(1420)}}&= \left(1435\pm2\pm7\right) -\mathrm{i}\left(40\pm2\pm1\right)\text{MeV}\,.\notag \end{align} The pole trajectories indicate that the $f_1(1285)$ originates from dressing a bare state introduced in the potential. In contrast, the $f_1(1420)$ is predominantly dynamically generated, and a single-channel analysis traces it to an $S$-wave $K\bar K^*$ quasi-bound state mixed with the nearby bare state, supporting its hadronic-molecule interpretation. We also find an additional pole deeper in the complex plane in the best-fit amplitude on the same Riemann sheet as the $f_1(1285)$. This additional pole is generated by the $P$-wave $\pi a_0$ contact interaction alone. It has a sizable cutoff and two-body-input dependence, and leaves little visible imprint on the physical lineshape. Finally, we provide a detailed and pedagogical appendix on how three-body cuts affect the solution of the integral equation.

We present a method for performing distributed quantum computing with controlled approximations for circuits that are weakly coupled via a single qubit. Exact distributed quantum computing requires exponential classical information to reconstruct the quantum process. However, we show how the classical cost is reduced to polynomial if the quantum procedure can be partitioned between a qubit that is weakly coupled to the other qubits. We demonstrate our method for a layered circuit based on the circuits used for the quantum approximate optimization algorithm.

Bell- and contextuality-type inequalities have become practical probes of many-body quantum correlations, often involving only few-body correlators and quantities with a direct Hamiltonian interpretation such as an energy density. Here we investigate the mechanism by which translation-invariant Hamiltonians generated from representative families of contextuality witnesses organize their ground-state structure in infinite one-dimensional systems. For the witness families considered, maximal quantum violation is realized by ground-state sectors with commensurate enlarged unit cells: the Hamiltonians are invariant under one-site translations, while the optimal ground states are $p$-periodic with $p>1$. At the corresponding classical-bound points, the ground-state sectors are highly degenerate and support many commensurate periods. Along the interpolation paths analyzed in this work, entering the contextual regime is accompanied by the lifting of this classical period degeneracy in favor of a quantum-selected period. We also identify finite periodic-boundary-condition benchmarks at the selected periods: for each model studied, the finite-ring witness reproduces the same classical bound and quantum value as the corresponding infinite-chain witness, and in several cases the resulting finite inequalities are tight. These reductions turn the infinite-chain contextuality certification into compact energy-estimation benchmarks requiring only local correlator measurements. We establish the mechanism analytically in representative two- and three-body witness models and corroborate it more broadly using translation-invariant semidefinite-program relaxations together with variational matrix-product-state calculations.

Large-deviation tails of critical probability distributions provide a sensitive probe of universality beyond standard finite-size scaling. We study these tails for critical percolation and Fortuin–Kasteleyn Ising models on two-dimensional lattices, three-dimensional lattices, and complete graphs. We consider two rescaled order parameters: the magnetization-like variable $x_m=|M|/\langle |M|\rangle$, including a signed cluster-mass analogue for percolation, and the largest-cluster variable $x_C=C_1/\langle C_1\rangle$. For $x_m$, we test the expected stretched-exponential large-deviation tail and show that the same form applies to the percolation analogue. For $x_C$, guided by the exact complete-graph result and scaling arguments, we propose universal scaling forms for both tails of the cumulative distribution and test them by extensive Monte Carlo simulations. In the complete-graph FK-Ising model, the left tail is governed by rare configurations with percolation-like scaling rather than by the typical Ising scaling. Our results show that the tails of order-parameter distributions reveal universal features of critical fluctuations that are not captured by averaged observables alone.

Context: Magnetic flux emergence is a fundamental driver of eruptive activity in the solar atmosphere. While many numerical studies employed idealized horizontal flux tubes, toroidal tubes provide a more realistic geometry for finite emerging loops with anchored footpoints. Aims: We compare the evolution and eruptive capability of horizontal and toroidal flux tubes under identical initial parameters. Methods: We performed 3D resistive magnetohydrodynamic (MHD) simulations of the emerging magnetic flux structures to evaluate their respective dynamics Results: Although the toroidal tube emerges later than in the horizontal case, it produces a higher frequency of eruption-driven jets (four versus two) because the supply of coronal axial flux is sustained. In contrast, the horizontal tube injects magnetic flux and energy more impulsively, driving stronger but less persistent activity and then rapidly stagnating when its atmospheric axial-flux reservoir is depleted. Free magnetic energy builds up after emergence and is released in discrete drops associated with eruptions. The toroidal case exhibits a quasi-cyclic buildup and release pattern, whereas the horizontal case relaxes to a lower-activity state after its early eruptions. The temporal evolution of relative magnetic helicity mirrors the free-energy evolution. Helicity increases with the stressing and twisting of the coronal field during emergence, peaks near eruptive episodes, and decreases as eruptions remove twisted flux, with the toroidal tube maintaining a more persistent helicity budget that supports recurrent events. Conclusions: Initial flux-tube geometry strongly controls the coronal flux budget and the storage and release of free energy and helicity, and therefore, the frequency and longevity of eruptive phenomena in emergence-driven active regions.

Stochastic resetting has emerged as a versatile protocol to drive quantum many-body systems to non-equilibrium steady states by interspersing unitary dynamics with measurements and resets at random times. In spite of this, a quantum hardware validation of such non-equilibrium steady states is still missing. Here, we achieve this goal by first formulating a noisy discrete-time theory where unitary gates alternate with noisy mid-circuit projective measurements and conditional resets. This noisy conditional resetting theory is then demonstrated on a superconducting quantum processor for up to $N=7$ qubits. We consider, as a paradigmatic case, the unitary dynamics of the interacting Floquet transverse-field Ising model. The stationary state of the noisy conditional resetting agrees quantitatively with the experiments, and it shows crossover behavior related to the equilibrium quantum phase transition of the model. Our results might thus pave the way for the preparation of collective stationary states on noisy quantum devices and for further developments of quantum algorithms involving mid-circuit measurements.

Forecast errors in high-resolution numerical weather prediction (NWP) systems are often linked to unresolved planetary boundary layer (PBL) processes, convection, terrain-induced circulations, and other vertically structured atmospheric phenomena. Previous work demonstrated that Long Short-Term Memory (LSTM) networks can successfully predict forecast errors in the High-Resolution Rapid Refresh (HRRR) model using mesonet observations, but we believe performance degradation is linked to periods of complex vertical atmospheric evolution. To address this limitation, we develop a hybrid LSTM-Vision Transformer (LSTM-ViT) framework that combines temporal sequence learning from surface observations with atmospheric profiles from the New York State Mesonet profiler network. The LSTM-ViT framework is trained to predict HRRR hourly precipitation, 10 m wind speed, and 2 m temperature forecast errors at individual mesonet stations. Across all three predictors, incorporation of profiler-derived atmospheric structure improves forecast error prediction skill relative to the baseline LSTM architecture, with the largest gains occurring at shorter forecast lead times and during periods of enhanced PBL activity. Improvements are particularly pronounced for precipitation forecast error, where the LSTM-ViT framework achieves approximately a twofold increase in predictive skill relative to the baseline LSTM while better capturing convectively driven error evolution and reducing degradation associated with PBL processes. These results demonstrate that combining temporal sequence learning with vertically informed attention mechanisms provides a physically meaningful pathway for improving forecast error prediction in operational NWP systems. Our research offers forecasters enhanced guidance regarding model bias and forecast confidence.

Calcium (Ca) insertion into graphite (C) has been considered to require elevated temperatures, and its occurrence at room temperature (RT) has been regarded as highly unlikely. Here, we demonstrate that sodium (Na) catalysis enables the formation of superconducting CaC$_6$ even at RT. In mixtures of Ca, Na, and graphite, the gradual development of superconducting diamagnetism and the emergence of X-ray diffraction peaks confirm the formation of CaC$_6$ during storage at RT. The superconducting transition temperature increases with storage time, and the amount of CaC$_6$ scales proportionally to the square root of storage time. These findings provide new insights into the mechanism of superconductivity and Na-catalyzed formation of CaC$_6$, and highlight the potential of this RT intercalation process for practical applications such as electrode materials in Ca-ion batteries.

The Dirac operator on a lattice cannot be both local and free of fermion doubling, at least not without breaking fundamental symmetries. Non-local, symmetry-preserving discretizations that avoid doubling have a quantum circuit representation as a linear-combination-of-unitaries (LCU) in which both the number of terms and their norm (the subnormalization factor) grow with the lattice size, compromising the efficiency of a quantum algorithm. We show that the tangent-fermion discretization escapes this obstruction when the Dirac equation is written as a generalized eigenvalue problem with a local operator pencil: Each member of the pencil has an exact LCU, with term count that is independent of lattice size and with subnormalization factor of order unity, on a par with elliptic operators. This provides an efficient block-encoding primitive for Dirac spectra and Green functions without fermion doubling.

We consider stratified steady water waves in a two dimensional channel. Our subject is branches of Stokes waves, bifurcating from laminar flows. We assume that the mass flux and the Bernoulli constant are fixed and consider the period of the wave as a parameter, which can change its value along the branch. A new class of density and Bernoulli functions is presented, for which laminar flows generate global bifurcation branches. The laminar flows are not necessary unidirectional and we show that the bifurcation branch can bifurcate from the laminar flow with arbitrary large period.

Optically addressable shallow donors in ZnO combine efficient spin-selective optical transitions with the potential for long spin coherence in an isotopically purifiable host lattice, making them an attractive platform for spin-photon quantum technologies. A key missing capability, however, has been coherent control beyond the small-angle rotations accessible with ultrafast optical pulses. Here we demonstrate coherent microwave control of implanted $^{115}\mathrm{In}$ donors in ZnO. Resonant optical pumping initializes and reads out the donor electron spin. Pulsed optically-detected magnetic resonance resolves the ten hyperfine transitions associated with the coupled $^{115}\mathrm{In}$ nuclear spin (I = 9/2) and reveals optical-pumping-induced nuclear spin polarization. We observe coherent Rabi oscillations with a maximum Rabi frequency of $\Omega/2\pi = 36.2 \pm 0.7$\;MHz, corresponding to a $\pi$-pulse time of 13.8$\pm$0.3\;ns, and characterize the spin coherence using Ramsey, Hahn echo and dynamical-decoupling measurements. Unexpectedly, the measured coherence is substantially shorter than reported in previous optical studies of donor spins in ZnO at high magnetic field. Control experiments rule out several simple explanations including microwave heating and instantaneous diffusion from the driven donor ensemble, leaving an open question regarding the origin of decoherence at low magnetic field in microwave-controlled ZnO donors. These results establish microwave control of ZnO donor qubits with resonant optical access to specific donor species. More broadly, they demonstrate that coherent microwave control can be achieved in optically addressable spin systems with nanosecond-scale inhomogeneous dephasing, enabling field-, temperature-, and materials-dependent studies of coherence-limiting mechanisms and the development of optically interfaced electron-nuclear spin registers.