Papers

SNe Ibn and SNe Icn are stripped-envelope explosions whose optical emission is commonly linked to interaction with H-poor circumstellar material (CSM), whereas fast blue optical transients (FBOTs) form an observational class of rapidly evolving, blue, and luminous events with diverse proposed power sources. We present a uniform comparison of these transients to test whether they are separated in optical light-curve and fitted physical parameter space. We compile multiband optical light curves of 25 SNe Ibn, SNe Icn, and FBOTs, measure same-band observables with Gaussian-process reconstructions, and model the data with the unified TransFit-CSM framework. In the observed (g)-band peak-luminosity–rise-time and decline–rise-time planes, the three classes are not cleanly separated: FBOTs preferentially occupy the luminous and rapidly evolving end of the distribution, but show limited overlap with part of the Ibn/Icn population. Their extinction-corrected peak colors span a broadly overlapping blue region, with FBOTs extending to bluer colors. Unified CSM-interaction fits, including shock heating and an effective inner heating component, yield overlapping CSM and ejecta parameter distributions. These results indicate that the optical light curves of SNe Ibn, SNe Icn, and at least some FBOTs can be compared within a common dense-CSM interaction framework, while the most extreme FBOTs may still require additional power sources or non-thermal components.

We study a slow heat-driven flow in a gas of elastically colliding hard disks confined to a long channel. The initial state consists of two regions with large temperature and density contrasts but nearly equal pressures, leading to a low-Mach-number, nearly isobaric evolution. In the dilute limit, the corresponding isobaric hydrodynamic theory reduces to a previously known ideal-gas description. We extend this theory to finite densities by incorporating a non-ideal equation of state of a hard-disk fluid, and solve the resulting one-dimensional equations numerically. Finite-density effects produce appreciable deviations from the ideal-gas prediction. We then test the theory directly against event-driven molecular dynamics simulations of hard disks and find very good agreement in both the dilute and finite-density regimes. The results provide, to our knowledge, the first particle-level test of isobaric gas dynamics of a strongly inhomogeneous cooling flow.

We investigate whether galaxies identified as superthin in optical images remain superthin in the near-infrared (NIR), and how their extreme disk morphology is related to environment. From a nearby volume-limited sample, we select 210 superthin galaxies using two-dimensional bulge/disk decomposition of SDSS $r$-band images, requiring the disk component to have a minor-to-major axis ratio $b/a<1/9$. We measure disk shapes from SDSS $griz$ to UKIDSS $JHK$ bands. Both the major- and minor-axis scales decrease from the optical to the NIR, reaching $\sim0.6$ of their $r$-band values in the $K$ band, but the disk axis ratio remains nearly unchanged. Thus, optically selected superthin galaxies remain superthin in the NIR, suggesting that any NIR-dominant thick component, if present, is not prominent enough to alter the fitted disk shape. Reanalysis of our sample and a previous superthin sample shows that earlier reported NIR thickening is mainly due to a magnitude- and band-dependent bias in one-dimensional fitting. We further compare their environments with matched control samples using projected cross-correlations, reconstructed local overdensities, and large-scale-structure classifications. Superthin galaxies show lower clustering on $\sim0.1$–$1\,h^{-1}\,\mathrm{Mpc}$ scales and lower overdensities at $1\,h^{-1}\,\mathrm{Mpc}$, but similar large-scale clustering and no clear residual dependence on large-scale-structure type. These results are consistent with a higher central-galaxy fraction and lower satellite fraction in the superthin sample, while the similar large-scale clustering points to comparable typical halo masses relative to the controls. This halo-occupation interpretation is qualitatively consistent with simulation-based scenarios in which high host-halo spin helps build extended thin disks, although the present data do not directly measure halo spin.

The leading small-x dipole relation for the gluon momentum form factor motivates an analysis of the additional fields needed to describe transverse stress. The spin-zero energy-momentum-tensor projector isolates a mixed leading and subleading field-strength product absent from a leading-plus-field background. We construct commuting, externally sourced gauge fields with a specified screened response and calculate their normalized stress functional. A weighted-moment identity fixes its forward sign and bounds its magnitude for sufficiently regular radial profiles, including profiles with sign-changing pointwise stress. For a Gaussian profile, a positive-weight integral representation yields an explicit error bound for the local approximation over a finite momentum-transfer window and constrains the normalized curvature independently of the response range. Coordinate-space stress relations provide regular pressure and shear benchmarks. A separate Coulombic color-singlet calculation compares filtered and unfiltered mixed fields in the same target: its point-source limit has linear range sensitivity, while a finite ultraviolet regulator changes the small-range behavior. A correlated refit of author-supplied pion form factors separates overall fit quality from range sensitivity. The full-window optimum lies at the infinite-range shape boundary, while the forward extrapolation depends on the fitted model. These results quantify approximation errors and inference limits within specified stress models. Their connection to the physical small-x gluon D-term requires renormalized QCD matching.

Neutron star mergers are a leading site of r-process, producing radioactively powered optical and infrared transients known as kilonovae. Observations of the kilonovae AT2017gfo, associated with the gravitational-wave event GW170817, and AT2023vfi, associated with GRB 230307A, have enabled measurements of the mass of ejected r-process material and identification of heavy elements in the ejecta. However, late-time observations reveal strong infrared emission with temperature below 1000 K, which is difficult to explain by atomic absorption and emission processes alone. In this paper, we propose that kilonova ejecta provide conditions favorable for the formation of dust grains composed of refractory r-process elements including Zr, W, and Os. Assuming a simplified, empirically derived single power-law temperature evolution and using W reaction rate coefficients as a proxy, our kinetic dust formation calculations indicate that dust could form efficiently, particularly in slow ejecta. This stands in contrast to a previous study that relied on a classical nucleation framework. By performing radiative transfer simulations that incorporate dust formation, we demonstrate that, if formed, r-process dust could naturally explain the observed late-time infrared emission, although refining ejecta parameters and geometry will be necessary to match specific observational cases. The formation and abundance of r-process dust are highly sensitive to ejecta mass, composition, and expansion velocity. Infrared emission from r-process dust may therefore potentially serve a new probe of heavy-element production in neutron star mergers.

In this paper, we investigate the chaos bound violation of spinning charged test particles in the Kerr–Newman–AdS spacetime by comparing the Lyapunov exponent of unstable circular orbits with the black hole surface gravity. We find that the violation is governed by the relative balance between the local orbital-instability and surface gravity scales, while spacetime rotation, charge, AdS curvature, and particle spin modify this balance in different ways. In rotating backgrounds, the violation depends strongly on the relative orientation between the particle total angular momentum and the black hole rotation, with anti-aligned configurations generally favoring violation. Particle spin further shifts the violation boundary through spin–curvature coupling, although its influence remains comparatively weak over the spin range considered. The cosmological constant has a background-dependent influence. These results show that the parameter dependence of chaos bound violation reflects the competition between the local orbital-instability and surface gravity scales.

We present a new catalog of spectroscopically confirmed white dwarfs from the Dark Energy Spectroscopic Instrument (DESI) Data Release 1. We visually classified 44,417 white dwarf spectra and derived atmospheric parameters for 29,072 DA white dwarfs through spectroscopic model fitting. The resulting mass distribution is non-Gaussian, with a mean mass of $0.677\,M_\odot$, consistent with previous studies. We identify 547 magnetic white dwarfs by detecting Zeeman splitting, including 84 new discoveries, and estimate their magnetic field strengths using off-centered, inclined dipole models when possible. We compare our magnetic field determinations with previous measurements and find overall good agreement. Finally, we investigate the relation between stellar properties and magnetism, finding that magnetic white dwarfs are systematically more massive than the general white dwarf population and that intermediate-strength magnetic fields are already present in stars that have not yet entered the crystallization phase. This result suggests that crystallization is unlikely to be the sole mechanism responsible for the origin of magnetic fields in white dwarfs.

Dielectric losses at surfaces and interfaces remains a primary limitation to coherence in superconducting transmon qubits. Niobium (Nb), a widely used material in superconducting quantum circuits, readily forms native oxides under ambient conditions, leading to lossy dielectric interfaces that degrade device performance. Here, we demonstrate a novel fabrication strategy that chemically transforms the native dielectric oxide on Nb into a metallic Pt–Nb surface alloy through post-oxidation Pt deposition followed by thermal annealing, thereby stabilizing Nb surfaces against further oxidation, potentially including sidewall regions. High-purity Nb films were fabricated with bulk-like superconducting transition temperatures ($T_c = 9.30\pm0.10$~K). Spectroscopic and microscopic analyses confirm the conversion of the native oxide into a chemically stable, metallic alloy-dominated layer that suppresses subsequent oxide growth. Ab initio simulations elucidate the atomic-scale rearrangement and electronic structure evolution associated with Pt incorporation into native niobium oxide, providing insight into the mechanism underlying the oxide-to-metal transformation and stabilization of the alloyed surface.

The JUpiter ICy moons Explorer (JUICE) mission, launched by the European Space Agency (ESA) in April 2023, represents one of the most ambitious deep space exploration endeavours targeting Jupiter's icy moons. This paper presents results from the Very Long Baseline Interferometry (VLBI) radio telescope tracking conducted by the University of Tasmania during the first two years of JUICE's cruise phase operations. We have conducted over 100 tracking sessions capturing the spacecraft across different orbital regimes as JUICE progresses through its complex cruise trajectory towards Jupiter. Our analysis focuses on three key areas: Doppler residual characterisation, mission performance indicator extraction, and solar wind scintillation pattern analysis (including space weather forecasting). UTAS measurements demonstrate the enhanced capabilities that VLBI networks provide for deep space mission support, particularly for precision orbit determination and spacecraft health diagnosis. The results showcase the UTAS VLBI array as a valuable complement to traditional tracking infrastructure, offering Southern Hemisphere coverage and enhanced geometric diversity for deep space missions.

Spin correlations are among the most fundamental quantum observables in many-body systems, yet they remain difficult to access experimentally in relativistic heavy-ion collisions. Existing spin measurements, including hyperon polarization and vector-meson spin alignment, have revealed important single-particle spin phenomena, but genuine two-particle spin correlations in the produced hadronic system remain largely unexplored. Here we propose spin femtoscopy, a framework for accessing genuine two-particle spin correlations through spin-resolved femtoscopic measurements. The key principle is that different two-particle spin configurations can give rise to different femtoscopic correlation functions because of quantum statistics and spin-dependent final-state interactions. Using $\Lambda\Lambda$ pairs as a proof of principle, we exploit the self-analyzing weak decay of $\Lambda$ hyperons to construct spin-sensitive femtoscopic correlation functions with different singlet and triplet admixtures. We show that these observables provide experimental access to the spin-state populations of the pair and allow genuine spin correlations to be separated from spin-dependent femtoscopic mixing caused by quantum statistics and final-state interactions. This work extends femtoscopy from a probe of source geometry and final-state interactions to a framework for revealing the quantum spin structure of strongly interacting matter.

We extend the exceptional-Jordan spectral framework for fermion mass hierarchies to the problem of quark and lepton mixing. Following the companion mass paper~\cite{Teli:2026jgr}, each fermion sector is associated with a Hermitian element of $J_3(\mathbb{O}_{\mathbb{C}})$, where adjacent square-root mass ratios are obtained from cubic ladders in $\mathrm{Sym}^3(\mathbf 3)$. Here, these ratios are used as inputs to an adjacent-edge lift from spectral hierarchy data to two-generation mixing angles. The lift is derived from a Fritzsch-type two-state texture~\cite{Fritzsch:1977za, Fritzsch:1979zq} and should be regarded as an effective bridge ansatz rather than a theorem of the Jordan spectrum alone. The exact CP-transport input is supplied by the companion CP Letter~\cite{GuptaTeli:2026aqf}. In the quark sector, the octonionic ladder operator $\alpha_2$ generates a real local rotor in the $(e_1,e_3)$ plane, and the up- and down-sector local Cabibbo-edge amplitudes are complex conjugates, giving the exact local law $\phi_{12}=-2\chi$. This is a transport-level Cabibbo-rung phase law, not by itself a prediction of the standard CKM Dirac phase. With the fitted companion mass ratios, the minimal two-angle extraction from the measured $|V_{us}|$ gives an effective Cabibbo-block phase $\phi_{12}\simeq 105.7^\circ$; this number is a bridge diagnostic, while the balanced octonionic rotor remains the distinguished quadrature reference point. The $(2,3)$ sector requires a phenomenological normalization $\kappa_{23}\simeq0.56$, and the direct $(1,3)$ element remains a long-edge bridge problem. [Truncated]

In this work, we propose a scheme to classify the molecular states consisting of ground single-charm baryons ($\Lambda_c$, $\Xi_c$, $\Sigma_c^{(*)}$, $\Xi_c^{\prime(*)}$, $\Omega_c^{(*)}$) and $\bar{D}^{(*)}/\bar{D}_s^{(*)}$ mesons. Within this framework, all considered baryon-meson systems are categorized according to the flavor components of their light degrees of freedom. We briefly illustrate how this classification scheme can consistently explain the experimentally observed $P_c$ and $P_{cs}$ states. This framework also predicts the existences of single-strange and double-strange hidden-charm bound states. The attractive interactions of these states arise from channel mixing between $\Sigma_c^{(*)}\bar{D}_s^{(*)}$ and $\Xi_c^{\prime(*)}\bar{D}^{(*)}$ for single-strange systems, and mixing between $\Xi_c^{\prime(*)}\bar{D}_s^{(*)}$ and $\Omega_c^{(*)}\bar{D}^{(*)}$ for double-strange systems, respectively. Using parameters fitted from the measured $P_c$ and $P_{cs}$ states, we systematically present the predicted mass spectra for these single- and double-strange hidden-charm bound states.

Spatially resolved maps of gas-phase metallicity provide key constraints on the chemical enrichment and mixing processes that drive galaxy evolution, but measurements based only on strong lines remain highly uncertain and dependent on emission-line coverage. In this work, we present a joint analysis of SITELLE observations, covering the $[O II]\lambda\lambda3726,3729$ doublet, with PHANGS-MUSE spectroscopy covering 4800-9300 Angstroms, including $H\beta$, $[O III]\lambda4959,5007$, $[N II]\lambda6584$, $H\alpha$, $[S II]\lambda\lambda6716,6731$, and $[S III]\lambda9069$, within five nearby spiral galaxies. By combining these data, we construct a homogeneous catalog of emission-line fluxes for 604 ionized nebulae, 556 of which are classified as H II regions. This enables a comparison of eight widely used strong-line metallicity calibrations, five new strong-line calibrations, and an investigation of ionization-parameter diagnostics. We recover known systematic offsets among calibrations, but also find that many exhibit very low scatter, less than 0.03-0.04 dex, in radial metallicity gradients. We find that $[S III]/[S II]$ exhibits minimal secondary dependence on metallicity or extinction, suggesting that it may be a more robust tracer of ionization parameter than $[O III]/[O II]$. No significant outliers are identified in O/H or N/O within the sampled regions, indicating internally consistent abundance trends across the inner disks probed by our data. We provide a publicly available catalog of all measured emission-line fluxes, designed to support future investigations, including temperature modeling and strong-line abundance calibrations.

The large anomalous Nernst effect in magnetic Weyl semimetals is one of the most intriguing transport phenomena, which draws significant attention for its potential applications in topological thermoelectrics. Despite frequent reports of substantial anomalous Nernst conductivity (ANC), methods to optimize Nernst thermoelectrics remain limited. Our research reveals that the magnitude of the ANC is directly related to the sum of the anomalous Nernst and Hall angles. While the sign of the anomalous Hall angle is relatively stable in a certain material, the sign of the anomalous Nernst angle can be intrinsically tuned. Therefore, the ANC can be effectively optimized by regulating these angles to work in concert. This finding is verified by experimental modulation from iron-doped magnetic topological material Co3Sn2S2. Additionally, we observed a robust TlnT scaling law of the ANC over the temperature range of 40 to 140 K in all studied samples, suggesting an intrinsic origin of the ANC. Considering the common opposite sign of the anomalous Nernst and Hall angles in many magnetic topological materials, our research offers an applicable scheme for optimizing the Nernst thermoelectrics.

Fusion of two epithelial cell sheets brought together in a bilayer configuration is a common step in animal morphogenesis, yet, in contrast to other epithelial fusion processes such as wound healing in a monolayer of cells, it has not been a strong focus of modeling efforts. Here we consider a preliminary stage of bilayer fusion, recently termed "docking." In multiple instances of docking that span apical and basal varieties, cells appear to have a tendency to remodel so as to co-localize their bilateral junctions (match their edges) across the bilayer. Motivated by this observation, we introduce a bilayer cellular Potts model that couples two standard 2D area- and perimeter-elasticity models via short-range, out-of-plane interactions between cell edges. The new coupling involves a single adjustable parameter that minimally models the combined effect of dynamic cytoskeletal protrusions, cadherins, and other potential edge-associated adhesion molecules. Our model predicts that bilayer edge matching is maximized when the two monolayers are in their fluid-like regimes (average cell shape index greater than 4.6 in our implementation), and when the bilayer coupling strength strikes a balance between in-plane and out-of-plane energy scales. At higher coupling strengths, the system tends to get stuck in metastable states with sub-optimal edge matching. Exploration of the mechanisms of edge matching reveals that pairs and quadruplets of coordinated T1 transitions play a particularly important role. We also find numerous examples of emergent features we term "domain walls" - branching or unbranching curves that cross no matched edges, but that separate regions of nearly complete matching. These domain walls can be both system spanning and long lived. Finally, we extend our model to crudely account for bending of the two sheets, and study the distributions of docking front speeds that result.

Simulating two-dimensional frustrated quantum matter is a grand challenge due to the sign problem and exponential Hilbert space complexity. In this work, we introduce the Holographic Quantum Transformer (HQT), a physics-inspired generative architecture that leverages global self-attention to resolve non-local entanglement patterns. We validate HQT on the square lattice $J_1-J_2$ Heisenberg model. On the heavily frustrated $8 \times 8$ lattice at the quantum critical point ($J_2=0.5$), HQT reaches a ground-state energy per site ($E/N$) of $\mathbf{-0.5001(1)}$, consistent with the expected finite-size scaling trend. Beyond numerical accuracy, HQT exhibits intrinsic physical awareness, autonomously recovering the underlying $J_2$ interaction geometry through interpretable attention maps. Our central contribution is “Holographic Transfer", a zero-shot size-extrapolation protocol with rapid alignment: a model trained on $8 \times 8$ systems is directly projected onto larger $10 \times 10$ lattices via continuous positional-embedding interpolation and head re-initialization, achieving high-fidelity initialization and rapid convergence. This zero-shot protocol yields an energy of $E/N = \mathbf{-0.49782(3)}$, statistically consistent with the variational state of the art while requiring no from-scratch training on the target lattice. Our results establish generative attention as a scalable paradigm for transferable quantum simulation.

The anomalous Hall angle ({\theta}A) is a measure of the efficiency of converting a longitudinal driving current to a transverse spin-polarized Hall current. For anomalous Hall sensing, a large anomalous Hall angle can improve the sensitivity of magnetic field detection. However, modulation of this angle is challenging and magnetic materials typically have low angles of 0.1 to 3{\deg}. Here, we report modulation of the anomalous Hall angle in the magnetic Weyl semimetal Co3Sn2S2. We propose that the angle parameter tan{\theta}A can be formulated as a function of the product of electrical resistivity and anomalous Hall conductivity. Our scheme was utilized to demonstrate the modulation of tan{\theta}A up to a magnitude of 0.46, corresponding to an angle of around 25{\deg}. Microfabricated anomalous Hall devices using Fe-doped Co3Sn2S2 single-crystalline nanoflakes exhibit a high Hall sensitivity of 7028 {\mu}{\Omega}ucm/T and a magnetic field detectability of 23.5 nT/Hz0.5 at 1 Hz.

In a recent article, Hod [1] has concluded the non-existence, heretofore unnoticed, of a unified Thorne's hoop conjecture that holds for the quasi-local mass, $\mathcal{M}(r\leq R_{+})$ for static Reissner-Nordstrőm black hole, but does not hold for the spinning electrically charged Kerr-Newman black holes, when the same quasi-local mass is used. While the conclusion is correct and important, we wish to point out a curious exception for which the conjecture holds in a unified way for both the static and spinning tidal charged $4d$ braneworld black holes of string theory, when the mass in the conjecture is the same quasi-local mass.

The Damour-Solodukhin wormhole (hereinafter DSWH) is known to mimic Schwarzschild black hole (hereinafter SBH) horizon in some properties. To act as a mimicker, the DSWH parameter $\lambda$ by definition is required to be extremely tiny, i.e., $\lambda \sim 0$. Our comparative analyses show that such a requirement may be too restrictive at least as far as the Bondi accretion profiles of the two objects, the DSWH and SBH, are concerned. Intriguingly, it turns out that some profiles of DSWH mimic those for the SBH near the horizon even at values of $\lambda$ considerably higher, i.e., $\lambda \sim 1$.

We study Floquet thermalization in a periodically driven quantum non-integrable Ising chain by combining two operational diagnostics: subsystem thermalization and work statistics. For generic interacting Floquet systems, stroboscopic dynamics lead to heating toward an infinite-temperature state at low driving frequencies, to a prethermal state during the crossover regime, and then to a finite-temperature state at high driving frequencies. We show that reduced density matrices of small subsystems provide a precise measure of local equilibration and clearly resolve prethermal plateaus. In parallel, we analyze the statistics of work performed over a Floquet cycle using both the characteristic function of work with and without the two-point measurements, and the related fluctuation theorem, which captures coherent contributions and deviations from thermal equilibrium. By comparing these two diagnostics within the same Floquet setting, we demonstrate that work statistics encode the same dynamical crossover that governs subsystem thermalization. Our results establish a unified and experimentally accessible framework for characterizing Floquet thermalization, prethermal regimes, and coherent energy absorption in interacting quantum systems.

Artificial intelligence (AI) and quantum information (QI) are rapidly co-evolving. AI is becoming a practical tool for learning, designing, controlling, and verifying quantum systems, while QI offers new computational models, representational structures, and learning-theoretic questions for AI. This survey reviews the interface from both directions. In the AI for QI direction, we organize recent progress around the central tasks of extracting information from limited measurements, training and discovering quantum algorithms, stabilizing noisy hardware, automating experimental and programming workflows, and extending learning-based methods to sensing and networking. In the QI for AI direction, we examine how quantum computation and quantum-inspired structures affect learning through algorithmic speedups, expressivity, trainability, generalization, neural-network design, and tensor-network representations. We close by identifying cross-cutting challenges in reproducibility, scalability, hardware realism, and co-design, arguing that progress will depend on tighter integration of theory, experiment, and hybrid quantum–classical systems.

This study aims to test whether a supermassive binary black hole (SMBBH) system with a triple-disk accretion structure can explain the observed $\sim$173-day periodic microlensing variations and spectral energy distribution (SED) of the gravitationally lensed quasar Q J0158-4325. We construct a triple-disk model for the SMBBH system, incorporating realistic accretion disk structures, orbital motion, and microlensing effects. The model is used to simulate optical and X-ray microlensing light curves and SEDs, which are compared with long-term optical monitoring, X-ray observations, and UV-optical spectra from HST and XSHOOTER. Bayesian analysis and MCMC fitting are applied to constrain model parameters. The model successfully reproduces the periodic microlensing variations. Combined light curve and SED fitting favor a high mass ratio ($q>0.5$) SMBBH system with total mass $\sim 10^{9.5}M_\odot$, and nearly equal-mass binaries ($q\sim1$) provides the best agreement with both the optical/UV spectrum and the microlensing signal. This model predicts larger X-ray microlensing amplitudes than in the optical, but, the available X-ray observations lack the precision needed to place strong constraints. We emphasize the need for future high-cadence monitoring to resolve remaining uncertainties. This study demonstrates the effectiveness of combining multi-wavelength microlensing signatures with spectral modeling to provide robust constraints on SMBBH systems, with the developed framework applicable to other lensed quasars for identifying and characterizing candidate SMBBHs.

Type Ia supernovae (SNe Ia) serve as one of cosmic standard candles, but their exact progenitor channel is still an open question. SNe Ia commonly come from binary star evolution. Therefore, one of the major differences among the proposed progenitor channels is whether there is a more-or-less intact companion star remaining at the time of explosion, which causes the SN ejecta to be more asymmetrical. As the SN ejecta evolved into supernovae remnants (SNR), the imprint formed by the companion interaction may affect the morphology of the SNR. In addition, the progenitor systems may have experienced different mass transfer histories and therefore led to formation of different circumstellar material (CSM) environments, which may also affect the early evolution of SNR. In this study, we use GADGET and RAMSES codes to simulate these physical effects and follow the evolution into early-phases of SNRs. In our simulations, we consider different ejecta models and track the element distribution. We compare our simulation with actual observations and conclude that despite some SNRs having morphology resemblance to our simulation results, their highly asymmetric expansion rates are hard to explain by interaction between SN ejecta and a companion star alone.

The microlensing of lensed quasars presents a promising avenue for understanding the structure of accretion disks around supermassive binary black holes (SMBBHs). We investigated the microlensing signatures in multiband (optical, UV, and X-ray) light curves of active SMBBH systems, focusing on how these signatures depend on the mass ratio, separation, and accretion rate. We analyzed the periodic fluctuations in microlensing light curves induced by the orbital motion of SMBBHs. We examined the relation between the mass ratio and the period of variations in light curves across optical, UV, and X-ray bands. We find that the periodic fluctuations in the light curves depend on the mass ratio of the black holes: for nearly equal masses, variations occur at half the orbital period, whereas for low mass ratios, the period corresponds to the orbital period influenced by the secondary mini-disk. Furthermore, all optical, UV, and X-ray light curves exhibit the same period and phase, but the amplitude of variation is greater in the UV and X-ray bands than in the optical bands. These light curves provide insights into the motion and radiation regions of the disks through wavelength-dependent periodic variations, although they yield limited constraints on the system's black hole mass or Eddington ratio, which can instead be derived from the spectral energy distribution (SED). Integrating microlensing data with SED observations is crucial for accurately constraining the parameters of SMBBH systems.

Soliton cores in fuzzy dark matter (FDM) deepen nuclear potentials and have been proposed to strongly boost Bondi accretion, potentially aiding rapid black-hole growth at high redshift. We test this in live Schrodinger-Poisson FDM cores coupled to isothermal gas, evolving a moving black hole that grows via a strictly mass-conserving sink. We measure boosts relative to the initial mean-density Bondi rate. Low-mass seeds, with initial black-hole masses less than about 10^6 solar masses, do not sustain large boosts: black-hole wandering and soliton sloshing drive bursty accretion, with dense gas only intermittently present near the black hole. Intermediate seeds, with initial black-hole masses around 10^7 solar masses, produce the most durable enhancement, reaching boosts of order 100 for sound speed cs = 60 km/s, while hotter gas approaches near-background Bondi rates. High-mass seeds, with initial black-hole masses around 10^8 solar masses, quickly exhaust the sink-scale reservoir and become supply-limited, suppressing long-lived growth despite the deepened potential. In general, central-potential deepening, for example by a soliton halo, does not guarantee long-lived fueling: sustained boosts emerge only when the black hole remains dynamically confined within the dense nuclear gas region. Our results suggest that SMBH formation channels relying on soliton-enhanced accretion alone are unlikely to provide sufficient early growth.

Computational efficiency is a critical requirement for transit searches in modern large-scale photometric surveys. We present Graphics Processing Units Transit Least Squares (GTLS), a GPU-accelerated implementation of the Transit Least Squares algorithm designed to reduce the computational cost of periodic transit detection while preserving TLS-like sensitivity to transit-shaped signals. GTLS parallelizes the dominant steps of the TLS search, including phase folding, transit-duration evaluation, moving-window depth estimation, and chi-squared calculation. Using Kepler-like long-cadence light curves and synthetic Kepler-like time series, we benchmark GTLS against the reference CPU implementation of TLS and the GPU-based BLS implementation in cuvarbase. On an AMD Ryzen 9 7950X CPU and an NVIDIA RTX 4090 GPU, GTLS processes a 3000-day synthetic light curve in approximately 138 seconds, compared with 3289 seconds for TLS. With two RTX 4090 GPUs, the runtime is reduced to approximately 79 seconds. In recovery tests, GTLS achieves detection performance statistically consistent with TLS, with a precision of 9.3 percent and recall of 79.4 percent, compared with 9.4 percent and 81.1 percent for TLS. These results demonstrate that GTLS enables efficient TLS-style searches for large photometric data sets from Kepler, TESS, PLATO, ET, and future missions. The source code is publicly available.

Magnetic fields are a fundamental component of astrophysical systems, yet many key questions about their origin, amplification, and role in structure formation and evolution remain unresolved. The SKA will mark a transformational step forward in addressing these questions, enabling studies of cosmic magnetism across a large range of spatial scales and environments. This overview summarizes the main science cases in the Cosmic Magnetism Science Working Group, which cover a huge breadth of scales from the smallest scales governing planet and star formation, all the way up to the large-scale structure of the Universe. The chapter summarizes the main observational techniques for studying magnetic fields, including direct polarization imaging, Faraday rotation, rotation-measure grids, and Zeeman splitting. We also address fundamental considerations of these studies including SKA-Low vs SKA-Mid and wide-area vs deep observing strategies.

Quantum steering ellipsoid (QSE) provides a faithful representation of a two-qubit state. When extended to tripartite systems, the steerability from a trusted party to different receivers is subject to volume monogamy relations, which only constrain the total steerability but cannot individually eliminate the steerability of an untrusted third party, leaving a potential channel for information leakage via steering. Here, we show that this residual steerability can be completely suppressed by selectively engineering bound states in local qubit-environment subsystems, without compromising the steerability between trusted parties. Specifically, when bound states are formed in the subsystems formed by the trusted parties and their environments but absent in the untrusted one, the untrusted party's QSE volume decays to zero, while the trusted party's QSE volume remains finite. Our results establish selective bound-state engineering as a mechanism for extreme volume monogamy, with potential applications in secure quantum communication with an untrusted third party.

We study the spin Hall (SH) effect for the Dirac electrons in terms of the spin and magnetic-moment accumulation coefficients $-\Gamma^{00} g_{s(m)z}^{\phantom{s(m)z} xy}$. We take short-range nonmagnetic impurities into account within the self-consistent $T$-matrix approximation. Similarly to the universal scaling for the anomalous Hall (AH) effect, we find three disctinct regimes by changing the electric conductivity $\sigma^{yy}$; the superclean regime with $-\Gamma^{00} g_{s(m)z}^{\phantom{s(m)z} xy} \propto \sigma^{yy}$ owing to the skew scattering, moderately dirty regime with almost constant $-\Gamma^{00} g_{s(m)z}^{\phantom{s(m)z} xy}$, and dirty regime with a new scaling relation $-\Gamma^{00} g_{s(m)z}^{\phantom{s(m)z} xy} \propto (\sigma^{yy})^{0.6}$ whose exponent differs from that of the AH conductivity. Our results construct a unified theory of the SH effect without any ambiguity of spin current.

We present a variational derivation of the Wallis product and its reciprocal from the four-dimensional singular harmonic oscillator. The inverse-square interaction is absorbed into an effective angular parameter $\nu$, so that the lowest exact energy in a fixed sector is $E_{4d,\mathrm{exact}}=\hbar\omega(\nu+2)$. Motivated by the radial Kustaanheimo–Stiefel relation $r=\rho^2$ between the four-dimensional oscillator and the three-dimensional Coulomb problem, we use the quartic trial family $R_a(\rho)=N\rho^\nu e^{-a\rho^4}$. The minimized variational energy yields an accuracy ratio governed by adjacent Gamma functions. In the large-$\nu$ semiclassical limit, this ratio approaches unity. Restricting $\nu$ to the odd sequence $\nu=2n-1$ gives the standard Wallis product, whereas the even sequence $\nu=2n$ gives its reciprocal form. The Coulomb-dual interpretation further relates the two branches to integer and half-integer effective angular sectors in the dual Coulomb/MICZ description. The result shows that Wallis-type infinite products persist under an inverse-square deformation of the oscillator and arise from a common Gamma-function structure in radial variational dynamics.