Measuring the chemical and isotopic compositions of gas giants and brown dwarfs provides insights into their formation pathways and birth environments. 2MASS J0249-0557 c is an L2-type planetary mass companion ($\sim 12 M_{\mathrm{Jup}}$) orbiting a pair of brown dwarfs in the $\beta$ Pic young moving group and vicinity. Its mass places it at the intersection of planets and brown dwarfs, making it an interesting target for constraining formation pathways at the planet-brown-dwarf boundary. Using high-resolution spectroscopic data of the planet acquired with CRIRES+ mounted on VLT, we conduct atmospheric retrieval with the radiative transfer code \texttt{petitRADTRANS} and the nested sampling tool PyMultiNest. We retrieve a C/O ratio of $0.57\pm0.01$, a metallicity of [M/H] = $0.18\pm0.05$, and a $^{12}$CO/$^{13}$CO ratio of $95^{+23}_{-17}$. We also retrieve atmospheric compositions for two benchmark brown dwarfs in the $\beta$ Pic YMG, 2MASSI J0443+0002 and SIPS J2000-7523, using CRIRES+ data and find consistent compositions. Together with 2MASS J0249-0557 c's wide separation from its host, its compositional consistency with benchmark brown dwarfs supports gravitational collapse in a star-like manner as its most likely formation mechanism. These results deliver a homogeneous comparison of three substellar members in the $\beta$ Pic YMG and vicinity. Their solar-like abundances provide a baseline for exoplanet members in the same moving group, such as $\beta$ Pic b, 51 Eri b, and AF Lep b, whose host stellar compositions are difficult to measure. Future comparisons of atmospheric compositions among this moving group offer the potential to distinguish between formation mechanisms for its planetary members.

The inverse Kohn-Sham (KS) problem seeks a local effective potential whose noninteracting ground state reproduces a prescribed electron density. Although many inversion formulations and schemes have been developed, they are often formulated in disparate languages, including reduced variational optimization, penalty regularization, response-based iteration, and PDE-constrained optimization. In this work, we develop a unified framework for inverse KS theory in two steps. First, we identify the fixed-density noninteracting constrained search and its density-potential duality as the natural variational anchor of the inverse KS problem. In this setting, the KS potential appears as the variational dual object associated with density reproduction, reducing to the familiar multiplier picture in regular regimes. Second, building on this anchor, we classify major inversion formulations according to how the KS state equations and density-reproduction condition are treated within the optimization architecture, with orbital orthonormality retained as an additional structural constraint. Within this framework, the Wu-Yang formulation appears as a potential-space reduced multiplier formulation, the Zhao-Morrison-Parr construction as a quadratic-penalty relaxation, and PDE-constrained approaches as explicit state-constraint formulations at the orbital level. Rather than comparing inversion formulations primarily at the level of implemented algorithms, the present work develops an optimization-theoretic formulation map. This viewpoint identifies where additive-constant ambiguity, asymptotic normalization, nonsmooth variational structure, metric choice, and weak-gap instability enter different inversion architectures, and it makes explicit how major inversion approaches are connected and where algorithmic design choices arise.

Accurately reconstructing and forecasting ocean fields from sparse observations is critical for both operational and scientific purposes. Optimizing sensor placement to maximize reconstruction skill remains challenging due to evolving ocean dynamics and practical deployment constraints. Traditional approaches, such as Empirical Orthogonal Functions, greedy search, or Gaussian processes, either assume static observation networks or scale poorly in high-resolution and non-stationary regimes. We introduce a differentiable adaptive sensor placement framework based on a Gumbel-Softmax sampling operator. Given an ensemble of forecasts or simulations, the method jointly optimizes a probabilistic sampling mask and the reconstruction mapping (e.g., Optimal Interpolation correlation lengths) under strict observation budgets. Numerical experiments are conducted for Sea Surface Height reconstruction in a Gulf Stream region through Observing-System Simulation Experiments using a state-of-the-art high-resolution ocean simulation. With a sensor budget of only 0.1% (fewer than 100 point-wise observations on a 14°x14° domain) the optimized sampling reduces the reconstruction RMSE by more than half (0.0908 m versus 0.1750 m) and increases explained variance by about 20% (93.1% versus 74.4%) compared with a uniform random strategy. The method remains robust when trained on noisy ensembles with significant spatial displacement (up to 1°), demonstrating practical applicability under forecast uncertainty. Overall, the framework provides a scalable, budget-aware approach to designing observation networks. Beyond improved skill, it yields interpretable sampling patterns that consistently target energetic regions such as eddies and fronts, offering a transferable tool for adaptive sensing in geophysical systems.

Scattering black holes spin up and gain mass through the re-absorption of orbital angular momentum and energy radiated in gravitational waves during their encounter. In this work, we perform a series of numerical relativity simulations to investigate the spin-up and mass-gain for equal-mass black holes with a wide range of equal initial spins, $\chi_{\rm i}\in[-0.7,0.7]$, aligned (or anti-aligned) to the orbital angular momentum. We also consider a variety of initial momenta. Furthermore, we explore a range of incident angles and identify the threshold between scattering and merging configurations. The spin-up and mass-gain are typically largest in systems with incident angles close to the threshold value, large momenta, and negative (i.e. anti-aligned) initial spins. When evaluated at the threshold angle, we find that the spin-up decreases linearly with initial spin. Intriguingly, systems with initial spin $\chi_{\rm i}=0.7$ sometimes experience a spin-down, in spite of an increase in the black-hole angular momentum, due to a corresponding gain in the black-hole mass. Across the simulation suite, we find a maximum spin-up of $0.3$ and a maximum increase in the black-hole mass of $15\%$.

We present high-angular-resolution ($\sim0.05^{\prime\prime}$, $\sim 60-250$ au) ALMA Band~6 observations from the HOTDISK project (Hot-Origin Tracer survey of DISKs of massive protostars) aimed at investigating the "hot-disk" chemical pattern traced by vibrationally excited water, NaCl, SiS, and SiO in the innermost regions around massive protostars. Ten targets were selected based on strong CH$_3$CN emission exhibiting clear rotational signatures and centrally concentrated SiO emission from lower-resolution observations. We detect vibrationally excited water emission toward 7 of the 10 sources. In all detections, the blueshifted and redshifted components are compact and located on opposite sides of the 1.3 mm continuum peak, with velocity gradients approximately perpendicular to the outflow axes, consistent with rotation on disk scales. Emission from NaCl and SiS is detected toward 5 of these 7 sources and exhibits similar kinematics, further supporting the presence of compact rotating structures. In contrast, commonly used hot-core tracers (e.g., CH$_3$CN and SO$_2$) primarily probe larger-scale envelope gas. These results demonstrate that vibrationally excited water, NaCl, and SiS are powerful tracers of disk structures on $\sim$100 au scales, when observed at sufficient angular resolution and sensitivity. The high detection rate suggests that hot-disk chemical patterns -- and thus compact rotating disks -- are common in massive star-forming regions, at least among sources with well-developed rotating envelopes.

We examine the role of anisotropic subgrid-scale (SGS) stress in wall-modeled large-eddy simulation (WMLES) of flow over a spanwise-uniform Gaussian-shaped bump, with emphasis on predicting flow separation. The simulations show that eddy-viscosity-based SGS models often yield non-monotonic predictions of the mean separation bubble size on the leeward side under grid refinement, whereas models incorporating anisotropic SGS stress produce more consistent results. To identify where SGS anisotropy is most critical, we introduce anisotropic SGS stress in selected regions of the domain. The results reveal that the windward side, where a strong favorable pressure gradient (FPG) occurs, is crucial in determining downstream separation. Analysis of the Reynolds stress transport equation shows that fluctuations of anisotropic SGS stress modify SGS dissipation and diffusion in this region, thereby altering the Reynolds stress and the onset of separation. Examination of the mean streamwise momentum equation indicates that at coarse resolutions, the mean SGS shear stress dominates, and the differences between the eddy-viscosity-based and anisotropic models remain minor. With grid refinement, resolved Reynolds stresses increasingly govern the near-wall momentum transport, and the influence of SGS stress fluctuations grows as they determine the SGS dissipation and diffusion of Reynolds stresses. Component-wise analysis of the SGS stress tensor further shows that the improvement arises mainly from including significant normal stress contributions. An a priori study using filtered direct numerical simulation of turbulent Couette-Poiseuille flow confirms that wall-bounded turbulence under FPG is highly anisotropic and that anisotropic SGS models provide a more realistic SGS stress representation than eddy-viscosity-based models.

We show that a three-dimensional superconductor with a non-Abelian SU(2) order parameter can support an extended resistive regime a Bose metal, in which transport is carried by bosonic electron-Majorana bound states - separating a uniform superconductor from a pair-density-wave (PDW) phase. The setting is a solvable Kondo lattice model introduced previously by the present authors, in which Kondo screening of a Yao-Lee $\mathbb{Z}_2$ spin liquid generates an order parameter with SU(2), rather than conventional U(1), symmetry, containing both superconducting and spin-density-wave components. Two effects cooperate to make fluctuations anomalously strong in three dimensions: the vanishing of the quadratic superconducting stiffness near the Lifshitz point where the optimal pairing momentum shifts from zero to finite $Q$, and the enlarged SU(2) order-parameter manifold. Building on our prior result that doping away from half-filling drives amplitude-modulated PDW order via finite-momentum electron-Majorana condensation, we analyze the fluctuation-dominated regime above that phase using a nonlinear sigma model. We find that the order-parameter propagator develops a ring of soft modes throughout the disordered phase, and that the resulting resistivity scales approximately as $R \sim T^3$ in three dimensions.

beta-Ga2O3 is a promising material for next-generation power electronics; however, its performance is strongly affected by lattice defects such as dislocations. In this study, we demonstrate three-dimensional (3D) visualization of dislocations in \b{eta}-Ga2O3 using synchrotron-radiation X-ray topo-tomography under a two-beam Borrmann-effect condition in transmission X-ray topography. By rotating the sample about the diffraction vector and acquiring a series of topo-tomographic images at different rotation angles, the evolution of dislocation contrast is captured, providing intuitive, depth-resolved visualization of dislocations. This method enables clear separation of dislocations in the epilayer and substrate in Schottky barrier diode structures, offering insight into dislocation propagation and their impact on epitaxial growth and device performance. This study represents the first demonstration of 3D dislocation reconstruction in beta-Ga2O3.

Chronic obstructive pulmonary disease (COPD) affects hundreds of millions of people worldwide, and skeletal-muscle dysfunction is clinically important. Quantum machine learning is increasingly explored for biomedical prediction, but its value in small biomarker cohorts requires benchmarking against strong classical baselines. We analysed a cigarette-smoke COPD cohort of 213 animals with blood and bronchoalveolar-lavage biomarkers to predict tibialis anterior muscle weight, muscle quality, and force. We developed a kernel-geometric quantum hybrid method in which synthetic symmetric positive definite (SPD) references are mapped through a reproducing kernel Hilbert space, compressed using train-only random projection, normalised, and supplied to low-dimensional quantum regression circuits. We benchmarked this approach against classical ridge/kernel models, SPD relational representations, and quantum-kernel regression (QKR). All methods were evaluated using condition-stratified repeated cross-validation. The largest numerical improvement was observed for muscle weight, where the proposed method had the numerically lowest mean root mean squared error (RMSE), approximately 1.8% below the best classical comparator; paired fold-level testing did not establish statistically significant superiority after Holm adjustment, but the endpoint is biologically meaningful. The method also had the numerically lowest mean RMSE for muscle quality. For force, biomarker-only Ridge performed best, suggesting a more linear endpoint structure.

This paper presents a novel nonlinear backstepping control law for continuous, low-thrust station-keeping in the Earth-Moon system. Quasi-periodic libration point orbits are targeted under a high-fidelity model of the dynamics. Almost global uniform exponential stability guarantees are attained, as shown through Lyapunov's stability theory. Saturation of the actuators is formally included in the controller design, such that these guarantees hold even in the event of saturation. The relationship between saturation threshold, control gains, and deviation is studied and an optimal procedure for gain selection is discussed. The control solution is tested numerically through a Monte Carlo analysis over representative application cases, subject to operational errors, constraints, and external perturbations. Station-keeping under actuation saturation is validated considering a conservative threshold for typical electric propulsion systems.

The era of large-scale, high-cadence astronomical surveys demands efficient and robust methods for time-series analysis. ARIMA models provide a versatile parametric description of stochastic variability in this context. However, their practical use is limited by the challenge of selecting optimal model orders while avoiding overfitting. We present a novel solution this problem by combining Autoregressive Integrated Moving Average (ARIMA) models with the Nested Sampling algorithm. Our method yields Bayesian evidences for model comparison and also incorporates an intrinsic Occam's penalty for unnecessary model complexity. Using JAX and Blackjax, a vectorized ARIMA-Nested Sampling framework with GPU-acceleration support is implemented, allowing us to perform model selection across grids of Autoregressive (AR) and Moving Average (MA) orders, with efficient inference of selected model parameters. We validate the approach using simulated time series with known ground-truth parameters and demonstrate accurate recovery of both model order and parameters. We then apply the method to several astronomical datasets, including the historical sunspot number record, stellar light curves of KIC 12008916 and Kepler 17 from the Kepler mission, and quasar light curves of 3C 273 and S4 0954+65 from the TESS mission. For all cases, except Kepler 17, the ARIMA models selected by this method were able to accurately model the stochastic variability in the time series data as well as produce accurate multi-step ahead forecasts for the sunspot number time series. Our results demonstrate that nested sampling offers a rigorous and computationally tractable alternative to autoregressive model selection in astronomical time-series analysis.

We study the optical depth to reionization in a cosmological setting that includes backreaction from matter inhomogeneities, using the Buchert averaging formalism. We construct a spacetime model consisting of multiple inhomogeneous domains, hereafter referred to as the backreaction model, characterized by a set of parameters. We first examine how these parameters influence the computation of the optical depth to reionization, $\tau_{reion}$. Next, we carry out a Markov Chain Monte Carlo (MCMC) analysis based on the PantheonPlus+SH0ES Type Ia supernova sample to infer the best-fit values of the model parameters, and then use these to evaluate $\tau_{reion}$. We obtain $\tau_{reion} = 0.0581^{+0.0105}_{-0.0096}$ (68$\%$ confidence limits). This result indicates that, when PantheonPlus+SH0ES data are used to constrain the model parameters, our backreaction model yields a value of $\tau_{reion}$ that aligns more closely with observational estimates than the value predicted by the standard cosmological model. We further demonstrate that the backreaction model leads to a modest reduction of the Hubble tension, while avoiding the need for exotic or non-standard physics.

A simple method is presented for deriving universal formulae for the correlators, frequently denoted $W_{g,n}(\{z_i\}), i=1,..n$, of a wide range of models of physical and mathematical interest. While many alternative methods exist for constructing such correlators, these formulae can be simply written in terms of one defining function and its derivatives. The method has been applied to the Airy and Bessel models, various minimal string and superstring theories, and their associated intersection theory settings, ordinary and various kinds of supersymmetric Weil-Petersson volumes, and more besides. For all these cases, their $W_{g,n}(\{z_i\})$ are just all specializations of the same universal formulae. A special variant of the method useful for ${N}{=}1$ supersymmetric cases is also presented. It allows for swift derivations of Norbury's three closed-form formulae for the volumes $V_{g,n}$ ($g{=}1,2,3$) of ${ N}{=}1$ supersymmetric Weil-Petersson volumes, and generalizations of them to a wider set of models. Moreover a new closed-form formula for the genus 4 case $V_{4,n}$ is derived. The straightforward method for how to derive such formulae for $g{>}4$ cases is described. Throughout, crucial roles are played by the underlying integrable KdV flows, as well as the Gel'fand-Dikii equation.

Type IIB string theory on AdS$_3 \times S^3\times T^4$ with RR flux as the near-horizon limit of the D1-D5 solution is expected to be dual to a (4,4) supersymmetric 2d CFT parametrized by the integers $Q_1,Q_5$ and other moduli. It is related by T-duality to type IIA string theory in the near-horizon limit of the D2-D4 solution which admits an uplift to the 11d AdS$_3 \times S^3\times T^5$ background which is the near-horizon limit of the M2-M5 solution. We point out that this relation allows one to use the quantum M2-brane description to probe ``non-planar'' corrections in the dual 2d CFT, in close analogy with the ABJM theory case (described by M-theory on AdS$_4 \times S^7/\mathbb{Z}_k$). We consider an analog of a supersymmetric Wilson loop (line defect) expectation value represented by type IIA string partition function expanded around AdS$_2\subset $AdS$_3$ minimal surface. Its M-theory analog is the M2 brane partition function expanded near AdS$_2\times S^1$. We compute the 1-loop contribution $Z_1$ to the M2 brane partition function and find that in contrast to the ABJM case in arXiv:2303.15207 (where $Z_1= (2\sin{\frac{2\pi}{ k}})^{-1} = \frac{k}{ 4 \pi} +\frac{\pi}{ 6k} +...$ contains an infinite series of higher genera string corrections, $k^{-1} \sim \frac{g_s}{ \sqrt {\rm T}}$), here it is given solely by the leading string-theory contribution $Z_1= \frac{\kappa}{ \sqrt{2\pi}}$ where $\kappa \sim \sqrt{Q_5}$ plays a role analogous to $k$. We also discuss a generalization to the mixed flux case which is straightforward from the 11d perspective.

We study a minimal $\mathbb{Z}_2$-symmetric extension of the Standard Model containing two singlet fermions and a singlet scalar that interact with the SM particles through the Higgs-portal. We identify regions of parameter space in which all three new particles are kinematically stable, giving rise to a multi component dark matter (DM) scenario. The parameter space consistent with the observed dark matter relic abundance are determined, and the contribution of each component to the total relic density is evaluated. While the DM-nucleon elastic scattering cross sections of the two fermionic dark matter components are loop-suppressed, the corresponding cross section of the scalar dark matter particle arises at tree level and is therefore expected to dominate. We find a viable region of the parameter space in which the scalar dark matter candidate with mass range of approximately $125-400$ GeV, evades current direct detection (DD) bounds while contributing only a small fraction of the observed relic density. In contrast, the fermionic dark matter possesses a loop-suppressed DD cross section that lies below the neutrino floor and can constitute a substantial fraction of the total relic density.

Amidst the exoplanet revolution in which multiple techniques have successfully found planets, the Doppler (Radial Velocity, or "RV") technique is unique in its sensitivity to giant planets at long orbital periods around Sun-like stars. The upcoming retirement of Keck-HIRES will incur irreversible changes in the continuation of HIRES's decades-long stable RV baseline and with it, the exoplanet community's ability to detect giant exoplanets with periods longer than Jupiter. With the time elapsed from the last HIRES RV for many stars of interest at ~3 years and growing, we tested the impact of a "critical RV", one that would bridge this gap between past HIRES RVs and future stable Keck-KPF RVs, on the recovery of long-period giant exoplanets. We generated 2000 1-planet systems with RVs sampled at a representative timeseries and used the planet-finding code Octofitter to perform injection-recovery experiments including and omitting this critical RV for each system. For the injected long-period super-Jupiters (~8-55 years, 1-13 $M_J$), including the critical RV induced a $1.5\times$ enhancement in overall planet recovery and a more specific $3.5\times$ enhancement in the recovery of super-Jupiters with Saturn-like periods. These experiments show that gathering a critical RV for stars of interest can help ensure that HIRES's decades-long stable RV baseline in conjunction with future KPF RVs, or indeed that the observationally-gapped RV baselines of any instruments that will undergo an RV zeropoint offset, will continue to be foundational to the discovery of long-period giant exoplanets in years to come.

The strongly correlated fermions play a vital role in modern physics. For a given fermionic Hamiltonian system, the most widely used approach to explore the underlying physics is to study the wave function that incorporates Fermi-Dirac statistics, which can be obtained variationally by energy minimization or by imaginary-time evolution. In this work, we develop an accurate tensor network method for one-dimensional interacting fermionic models based on the coherent-state path-integral representation of the fermionic partition function. Employing the coherent-state representation, the partition function is effectively represented as a (1+1)-dimensional anisotropic Grassmann-valued tensor network, and the Grassmann version of the corner transfer-matrix renormalization group algorithm is developed to contract the tensor network and evaluate physical quantities. We validate our method in the one-dimensional fermionic Hubbard model with a magnetic field, where the essential features of the phase diagram in the $(\mu, B)$ plane are quantitatively captured. Our work offers a promising approach to interacting fermionic models within the framework of tensor networks.

Extremely high-peaked BL Lac objects - also named extreme blazars - are among the most energetic and persistent extragalactic accelerators in the Universe, defined by a synchrotron emission peaking above $10^{17}$ Hz in X-rays. Such emission is then reprocessed and produces radiation extending deeply into very-high-energy (VHE, energy E>100 GeV) gamma rays. Observations in this energy band - optimally investigated by the Imaging Air-Shower Cherenkov telescopes - are crucial for probing the physical processes that drive their extreme behavior. This study extends our investigation of extreme blazars in the VHE gamma-ray range, providing a second new mini-catalog of sources observed by the MAGIC telescopes. We report on the monitoring of seven targets between 2017 and 2025, including four newly observed sources and three that have been part of long-term observation campaigns, for a total of approximately 338 hours of observations. The analysis of MAGIC data reveals two new VHE detections of extreme blazars, along with three additional sources showing hints of VHE emission. Joint observations of MAGIC and the first Large-Sized Telescope (LST-1) also confirmed a new VHE extreme blazar. Our results are complemented by simultaneous multiwavelength observations in other energy bands, including optical-UV, X-rays, and high-energy gamma rays (100 MeV<E<100 GeV). We confirm typical behavior of extreme blazars, such as a modest variability and a ``harder-when-brighter'' trend in X-rays across the sample. This new set increases the population of extreme blazars and their broadband analysis confirms the physical properties of these extreme sources.

We study the photon bulk-to-bulk propagator in AdS in various gauges, including axial, Coulomb, and the standard covariant gauge. We compute the propagator using both momentum and position space techniques. We ensure the propagators obtained obey the right subsidiary conditions arising from gauge invariance. In particular, BRST invariance implies a relation between the longitudinal components of the gauge field propagator and the ghost bulk-to-bulk propagator. Our method relies on decomposing the components of the propagator in terms of independent tensor structures and solving for the form factors. We recover some previously existing results and obtain new expressions for the propagator in other gauges. The propagator in axial and Coulomb gauge is simpler in momentum space, as momentum space makes manisfest the translational invariance in the boundary directions, while the position space expression is the simplest in the covariant Fried-Yennie gauge. In this gauge the propagator has an improved IR behavior, somewhat analogous to the UV improved behavior associated with the Landau gauge in flat space. The results readily extend to Yang-Mills fields.

The scalar potential of any particle-physics model must be bounded from below (BFB). We consider the extension of the Standard electroweak Model with three $SU(2)$ doublets of scalars and a symmetry under which each of those doublets changes sign. In the absence of necessary and sufficient conditions for boundedness from below (BnessFB) for this specific model, we argue that one may use increasingly stringent sets of necessary conditions. We introduce a Mathematica code, StableWein, that implements this idea. The user is allowed to choose the level of accuracy that they want in the determination of BnessFB; more precision means the use of more necessary conditions, and usually entails a longer running time for the code. Our investigation suggests that our procedure and code can be extremely precise in the determination of the potentials that are BFB. In addition, we introduce a machine-learning code that identifies, with more than 99% accuracy, which potentials are BFB.

Finding the first generation of (Population III or Pop III) stars is one of the most ambitious and exciting challenges of astrophysics. JWST opened concrete prospects for their detection during the Epoch of Reionization (EoR), where increasing evidence suggests that residual Pop III formation may persist, even within pristine pockets of high-mass halos, due to inhomogeneous enrichment. However, the identification of Pop III stars within globally enriched environments will be challenging. We investigate the detectability of a subdominant Pop III component in/around massive ($M_\star \gtrsim 10^9 ~\mathrm{M_\odot}$) galaxies at $z \approx 6.5 - 9$ from the dustyGadget cosmological simulation suite, and the confusion arising from second-generation (Pop II) stars in their surroundings. We find that young ($\lesssim 1$ Myr), massive ($M_\mathrm{III} \sim 6 \times 10^5 ~\mathrm{M_\odot}$) Pop III clusters forming within these galaxy environments are responsible for strong HeII1640 line emission ($L_\mathrm{HeII1640} \gtrsim 10^{41} ~\mathrm{erg \, s^{-1}}$), which would be detectable with $\approx 10 (50)$ h of medium-resolution observations with NIRSpec/IFU at $z \approx 6 (10)$. These bright luminosities cannot be produced by standard Pop II populations alone. On the other hand, the dominant Pop II component within massive ``hybrid'' Pop III hosts powers strong metal line emission ($L_\mathrm{[OIII]5007} \gtrsim 10^{42} ~\mathrm{erg \, s^{-1}}$), indicating that the detection of metal lines alone cannot exclude the presence of Pop IIIs in high-$z$ galaxy environments. We further discuss candidate selection strategies based on Ly$\alpha$, H$\alpha$ and H$\beta$ emission, and how spatially resolved observations may enable the detection of isolated, pristine pockets in the outskirts of massive halos.

The Nordic countries have adopted ambitious climate targets that require far-reaching power-sector transformations, making energy system modelling an important input to long-term planning. However, model-based evidence is produced using different model structures, assumptions, scopes, and scenario designs. This paper examines what can be learned from comparing such independently developed scenarios by assessing Nordic power-sector climate-neutrality pathways across eight structurally diverse energy system models. The comparison covers Denmark, Finland, Norway, and Sweden for 2030, 2040, and 2050, and focuses on electricity demand, generation capacity, CCS deployment, and power-sector CO2 emissions. Inputs are not harmonised; instead, outputs are compared using a common reporting basis reflecting how modelling evidence is encountered in applied policy contexts. The results show broad agreement on the direction of transition. Wind power, mainly onshore but complemented by offshore wind in some countries, is the clearest cross-model finding and forms the backbone of the Nordic power system by 2050. At the same time, installed capacities, CCS deployment, nuclear outcomes, and emissions levels vary substantially. These differences are interpreted considering renewable-resource potentials, technology availability, policy constraints, sectoral and geographical scope, emissions-accounting boundaries, and different implementations of climate-neutrality targets. The study shows that non-harmonised model comparisons can support policy analysis by identifying where models point in the same direction, such as wind expansion, and where outcomes depend more strongly on model and scenario assumptions, such as CCS, nuclear, and net-negative emissions. For policy use, the findings underline the need to report model scope, technology representation, policy constraints, and emissions-accounting boundaries..

Forbidden $\beta$ transitions are important for understanding the reactor antineutrino anomaly. Starting from chiral two- plus three-nucleon forces, we have derived the valence-space effective Hamiltonian and effective operators of first-forbidden transitions using the many-body perturbation theory. 20 dominant first-forbidden transitions have been investigated, which provide important contributors to the reactor antineutrino spectrum anomaly. Calculated $\log ft$ values are in reasonable agreement with experimental data. Obtained shape factors exhibit significant deviations from the values approximated with forbidden transitions treated as allowed transitions. The ``5 MeV bump'' observed in the experimental ${}^{235}$U-fission antineutrino spectrum was discussed with self-consistent shape factors obtained in the present \textit{ab initio} calculations. Unlike phenomenological models that require empirical quenching factors to reproduce $\beta$-decay data, the present \textit{ab initio} calculations do not need to introduce quenching factors for calculations of the first-forbidden transitions.

We study the Heisenberg spin-1/2 model on a semi-infinite chain - or, equivalently, a trotterized unitary SU(2) symmetric six-vertex quantum circuit - with a boundary defect where the interaction between the two spins nearest the edge differs from that in the bulk. For sufficiently strong boundary interaction we explicitly construct a conserved operator quasi-localized near the boundary using a matrix-product ansatz. This quasi-local edge mode leads to non-decaying boundary correlation functions, corresponding to a nonzero boundary Drude weight. The correlation length of the edge mode diverges at a finite critical value of the boundary interaction, signaling a transition to ergodic boundary dynamics for subcritical interactions.

Using density functional calculations and multi-orbital, multi-atom cluster exact diagonalization that includes local exchange and Coulomb interactions, we explored the local low-energy electronic states of trilayer La$_4$Ni$_3$O$_{10}$ via a minimal Ni$_3$O$_{14}$ cluster. We find that, at ambient pressure, starting with all three Ni being nominally 2+ valence, one of the two extra holes is localized in the central NiO$_2$ layer forming a Zhang-Rice singlet (ZRS) with $d_{x^2-y^2}$ orbital. The other hole mainly occupies the antibonding combination of the two interplane apical O $p_z$ orbitals and thereby hybridizes with an out-of-plane three-spin-polaron (3SP) formed by the $d_{z^2}$ orbitals of three NiO$_2$ layers. At high pressure, however, the two extra holes are concentrated on one of two outer layers and the inner layer separately forming the ZRS with $d_{x^2-y^2}$ orbitals. We highlight the similarities between the bilayer La$_3$Ni$_2$O$_7$ and trilayer La$_4$Ni$_3$O$_{10}$ via speculated possible charge and spin configurations as well as the in-plane 3SP on two neighboring clusters suggested by our isolated cluster this http URL thereby propose that the hole transfer from apical to in-plane oxygen orbitals of outer layer generates in-plane 3SP-like quasiparticles that act as mobile carriers coupled by interlayer superexchange; while the interplane 3SP-like states may provide the pairing glue. Since the low-pressure phase lacks freely propagating in-plane quasiparticles, this scenario naturally favors SC in the high-pressure phase.

We analyze branch decoherence in inflationary quantum cosmology by computing reduced density matrices and branch-overlap factors for long-wavelength perturbations. The Hartle-Hawking no-boundary state is real in the semiclassical regime and contains both expanding and contracting WKB components, whereas the tunneling state is selected as an outgoing complex WKB branch; expanding-contracting decoherence is therefore central for the former and mainly diagnostic for the latter. Using the influence-functional formalism, we derive the noise kernel for a light spectator environment and evaluate decoherence under horizon-based and EFT-motivated coarse grainings. We then compute the single-mode branch overlap directly from the Bunch-Davies mode functions, obtaining $|\mathcal{D}_k(z)|=[z^2/(z^2+1)]^{1/4}$ in the massless limit and $|\mathcal{D}_k(z)|\sim z^\nu$ on superhorizon scales for massive fields, where $z=-k\eta$ is the dimensionless wavenumber with $\eta$ the conformal time. In the massless case, the accumulated geometric branch functional is evaluated in closed form, with a leading cutoff-sensitive phase-space term and a universal subleading contribution. The calculation provides an explicit quantitative bridge between quantum-cosmological boundary conditions, inflationary squeezing, and the emergence of effectively classical cosmological histories.

We realize a cold-atom system to quantitatively test relational constructions of time. A well-isolated atomic Bose-Einstein condensate evolves in a conservative trap that is partitioned by a thin optical barrier into an observed and unobserved sector, with negligible dissipation on the experimental timescale. Motivated by relational-time approaches discussed in the Wheeler-DeWitt framework, we ask whether the dynamics of the observed sector can be ordered using only internal degrees of freedom. To this end, we construct an entropic time from an experimentally defined coarse-grained entropy, and demonstrate that it can robustly order the events in the observed sector across repeated cycles of expansion and recollapse. We finally derive an effective Schroedinger equation parameterized by this internal time and show that it is able to reproduce the measured evolution. These results establish a controlled experimental setting in which relational-time constructions can be quantitatively tested.

While hidden, singly, doubly, and fully heavy tetraquark states have been experimentally observed, triply heavy tetraquark states remain experimentally unconfirmed. We systematically investigate the spectroscopic and decay properties of four triply heavy-flavor tetraquark systems ($cc\bar{c}\bar{n}$, $cc\bar{c}\bar{s}$, $bb\bar{b}\bar{n}$, $bb\bar{b}\bar{s}$; $n=u,d$) based on the nonrelativistic quark model. Using an effective Hamiltonian, we employ the Gaussian expansion method to solve the four-body Schrödinger equation and incorporate the effect of color-spin configuration mixing. Results show both $cc\bar{c}\bar{q}$ and $bb\bar{b}\bar{q}$ systems have two $J^{P}=0^{+}$, three $J^{P}=1^{+}$, and one $J^{P}=2^{+}$ states, with ground-state masses of 5.2-5.5 GeV and 15.0-15.3 GeV, respectively. Root-mean-square radius analysis supports compact tetraquark configurations. All states are unstable, with rearrangement strong decays dominant and negligible radiative decays. Narrow resonances (e.g., $T_{c^{2}\bar{c}\bar{s}}(5360,0^{+})$, $T_{b^{2}\bar{b}\bar{n}}(15148,2^{+})$) arise from Feynman amplitude cancellation. We propose experimental searches in $J/\psi D^{*}_{s}$/ $\eta_{c}D_{s}$ (5.3-5.4 GeV) and $\Upsilon B^{*}$ (15.1-15.2 GeV) channels, providing key guidance for triply heavy tetraquark identification.

X-ray interferometry provides valuable information in terms of attenuation, small-angle scatter, and differential-phase contrast. This multi-modal contrast can aid in many clinical applications, such as lung diseases and breast cancer. However, standard interferometry has an analyzer grating that can increase the dose requirement to maintain the same image quality as a standard X-ray. We propose the use of super-resolution methods for X-ray grating interferometry without an analyzer, with detectors that fail to meet the Nyquist sampling rate needed for traditional image recovery algorithms. Detector phase steps are used to nominally recover the fringe sampling, followed by iterative recovery of the visibility and object parameters. This method enables Talbot-Lau interferometry without the X-ray absorbing analyzer. Removing the absorbing analyzer grating may improve dose efficiency and reduce system complexity. We demonstrate the use of super-resolution methods to iteratively reconstruct attenuation, differential-phase, and dark-field images using simulations of two-dimensional lung phantoms with lesions. A direct CdTe detector was simulated with pixel sizes of 55, 75, and 150 micron. The simulation results show that the proposed super-resolution iterative reconstruction method for Talbot-Lau Interferometry remains stable under the simulated noise conditions and can recover image parameters in cases where traditional algorithms cannot be used.

We develop a formulation of the strong deflection limit for the scattering of particles following timelike geodesics in asymptotically flat, static, and spherically symmetric spacetimes. For fixed specific energy, as the angular momentum approaches its critical value from above, the particle passes arbitrarily close to the associated unstable circular orbit, undergoes many windings around it, and the deflection angle diverges logarithmically. Using the geodesic deviation equation, we show covariantly that the coefficient of this logarithmic divergence is determined by the radial instability exponent of the critical trajectory, defined per unit azimuthal angle. We express this instability exponent in terms of local curvature data on the unstable circular orbit, thereby providing both kinematic and geometric interpretations of the strong deflection limit. In general relativity, its matter dependence enters only through a single local scalar combination constructed from the static-frame energy density and the principal radial and tangential pressures.