Optics
Reliability-Aware Bayesian Optimization of 1310 nm PCSELs with FDTD Verification
Jinglin Yu, Feiyang Wu, Longying Wen et al. (+3 more)
Near 1310 nm photonic-
crystal surface-emitting
lasers (PCSELs) are attractive narrow-beam sources for optical communication and sensing, but their final design refinement is costly. Small geometry changes simultaneously shift the band-edge resonance, cavity leakage, far-field divergence, and the numerical stability of a high-$Q$ decay fit, while every full-wave trial requires a time-domain simulation. We couple a commercial finite-difference time-domain solver to a reliability-aware
Bayesian optimization (BO) loop over eight local design variables. Each completed simulation updates the surrogate used to choose the next geometry. Candidate ranking combines wavelength and beam-quality requirements with a reliability-adjusted metric $Q_{\mathrm{eff}}$ derived from the solver-reported relative fit-error estimate $dQ/Q$. Across three 80-evaluation runs from the same reference model, BO produced 5–15 candidates per run that passed the joint filter. Designs reconstructed from fresh model copies retained $Q_{\mathrm{eff}}=4.33\times10^6$–$7.76\times10^6$, a 60–108-fold increase over the baseline metric, at 1308.23–1310.90~nm with approximately $0.84^{\circ}$ divergence. Under equal budgets, BO gave the highest mean strict-filter yield (9.0 candidates), compared with differential
evolution (7.0) and Latin-hypercube sampling (1.5), although the controls occasionally matched the peak $Q_{\mathrm{eff}}$. Field maps, resonance spectra, and local perturbations further identify an index-related wavelength handle and a hole-size-related leakage handle. The resulting FDTD budget produces a pool of wavelength-compatible, narrow-beam, and reproducible high-$Q$ PCSEL candidates without trusting a single optimistic decay fit.
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All authors Jinglin Yu, Feiyang Wu, Longying Wen, Chongxian Yuan, Renjie Li, Zhaoyu Zhang
General Relativity and Quantum Cosmology
Erik Bertram
We develop a local and covariant framework for constraining the
evolution of generalized
entropy along null horizons, combining classical
geometric methods with constraints from
quantum field theory. Building on the
quantum focusing
conjecture (QFC), which restricts
entropy evolution along null directions, we derive a Raychaudhuri-type differential inequality for the generalized expansion that makes its local dependence on expansion and shear explicit. The resulting relation, $\frac{d\Theta}{d\lambda} \le -\theta \Theta + \tfrac{1}{2}\theta^2 - \sigma^2$, reveals a direct interplay between expansion and shear in controlling
entropy flow: shear contributes negatively and yields a monotonic suppression of the generalized expansion in shear-dominated regimes, while expansion provides a competing
geometric source term. This structure provides a local
geometric formulation consistent with the QFC and clarifies its interpretation as a constraint on
entropy evolution. We further show that
quantum extremal surfaces correspond to configurations characterized by $\Theta=0$, whose local stability properties are governed by the same
geometric data. In addition, we derive a bound on the exponential separation of nearby null generators, indicating that the same combination of expansion and shear also controls
geometric instability. Our results provide a local
geometric refinement of
entropy bounds in semiclassical
gravity and establish a direct connection between null geometry,
quantum energy conditions, and
entropy flow, offering a local
geometric perspective on horizon thermodynamics beyond global formulations.
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Instrumentation and Methods for Astrophysics
The FastrSHWFS Development & Test Results
Natasha Popenoe, Benjamin Gerard and Dominic Sanchez
The recent 2020 Decadal Survey of Astronomy and Astrophysics listed habitable
exoplanet imaging with future extreme adaptive optics (AO) on 30m-class
telescopes as a key priority in the coming decade. However, there is a current 100x contrast gap between the best systems today and what is needed to enable this goal. Astronomical AO is a required approach to enable ground-based diffraction-limited imaging of
exoplanets on future extremely large
telescopes. Time lag between the end of an exposure and the application of deformable mirror commands is a major contributor to the error budget in many AO systems, and detector read time is often a large component of this lag. We present two designs for a modified Shack Hartmann wavefront sensor (SHWFS), named Focal plane Actualized Shifted Technique Realized for a SHWFS (fastrSHWFS), to reduce the time lag component. This design steers the spot pattern at the focal plane into a rectangular or linear array with a custom aspect ratio, reducing readout time. These masks were made by a recently available gray-scale two
photon polymerization 3D printing technology that in principle provides sufficient depth resolution and dynamic range for such masks. The mask with focus yields aberrated results while the mask with tip/tilt only yields some defined spots. This manuscript outlines the current SHWFS concept, our fastrSHWFS theoretical solution to addressing time lag, reflection and quality analysis of printed mask designs, and results from testing both masks on the High Contrast Testbed at Lawrence Livermore National Lab. This work follows the test of a previous fabricated fastrSHWFS masks that had insufficient optical quality.
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High Energy Physics (Phenomenology)
Probing Lorentz invariance via diphoton decays of the Higgs boson
Alan Kostelecky, Connor A. Petway and Nathaniel Sherrill
The prospects for observing small departures from Lorentz invariance are studied using effective interactions of the
Higgs boson with
photons. A single operator of mass-dimension five suffices to describe all leading signatures of Lorentz violation in the diphoton decay channel. Comparison of the theoretical modified decay rates with observed signal strengths measured by the ATLAS and CMS Collaborations at the Large
Hadron Collider indicates an estimated attainable sensitivity to the corresponding coefficients for Lorentz violation of order $10^{-4}$ GeV$^{-1}$.
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Quantum Physics
Tunable nonlinear electromechanics at the zero-point motion scale
Christoffer B. Møller, Roger Tormo-Queralt, Elsa Vázquez-Rodríguez et al. (+13 more)
Nonlinearity at the scale of zero-point motion opens new possibilities for the control and readout of nanomechanical systems, but achieving this remains a formidable challenge. Here we demonstrate that ultrastrong coupling (USC) between a nanotube mechanical oscillator and a double-
quantum-dot electronic two-level system enables a mechanical Kerr (Duffing) nonlinearity at the zero-point motion scale. In the dispersive regime, this large coupling yields a mechanical anharmonicity of $\alpha = 1.4\%$ - three orders of magnitude larger than in previous work - while preserving the predominantly mechanical nature of the lowest energy states. We further demonstrate a purely quadratic cavity-based continuous readout of the mechanical motion. This continuous nonlinear optomechanical readout is enforced by a double-
quantum dot
symmetry, which can be broken by gate tuning to introduce a large linear transduction. These results establish a tunable USC platform that enables strong mechanical anharmonicity and nonlinear continuous readout at the zero-point motion scale.
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All authors Christoffer B. Møller, Roger Tormo-Queralt, Elsa Vázquez-Rodríguez, Victor Román-Rodríguez, Marta Cagetti, Eneko Mateos-Madinabeitia, Janine C. Franz, Stefan Forstner, Sergio L. De Bonis, Luca Ornago, Maria El Abbassi, Seoho Jung, Andrew N. Cleland, David A. Czaplewski, Fabio Pistolesi, Adrian Bachtold
Mathematical Physics
Nonlinear Schrödinger equation on a closed 3D elastica knot
Alain J. Brizard
The present work introduces a new relation between closed elastica
knots with the solution of the nonlinear Schrödinger equation (NLSE) through the Hasimoto transformation. An elastica
knot is defined in terms of the Frenet-Serret
curvature $\kappa(s,t)$ as a function of the arclength $s$ along the spatial curve ${\bf r}(s,t)$ at a fixed time $t$, which is a solution of the
curvature differential equation $\partial^{2}_{s}\kappa(s,t) = -\;\kappa^{3}/2 + k_{0}^{4}\tau_{0}^{2}\;\kappa^{-3} + \lambda\,k_{0}^{2}\kappa/2$. Here, the Frenet-Serret torsion $\tau(s,t)$ satisfies the conservation law $\kappa^{2}(s,t)\,\tau(s,t) \equiv k_{0}^{2}\,\tau_{0}$, while the constant of integration $\lambda$ is associated with the constrained variation. After briefly reviewing the Hasimoto transformation from a space curve ${\bf r}(s,t)$ to the nonlinear Schrödinger equation (NLSE) $-\,iD^{-1}\partial_{t}\psi = \partial^{2}_{s}\psi + \frac{1}{2}\,|\psi|^{2}\psi$, where the constant $D$ has units of fluid circulation (m$^{2}$/sec), we show how the traveling-wave solution $\psi(s,t) = \Psi(s_{t} \equiv s - c\,t) \equiv \kappa(s_{t})\;\exp[i\theta(s_{t})]$ is mapped onto the
curvature equation for an elastica
knot, with $\theta^{\prime}(s_{t}) \equiv c/(2D) + k_{0}^{2}\tau_{0}/\kappa^{2}(s_{t})$ and the elastica-
knot constant $k_{0}^{2}\lambda = -\frac{1}{2}\,(c/D)^{2}$ expressed in terms of the traveling-wave NLSE parameters $(c,D)$. The constraint of a closed 3D elastica
knot imposes spatial periodicity conditions that introduce a unique set of
knot parameters for which the NLSE traveling wave can exist. The present work shows that the NLSE traveling-wave solution on a closed elastica
knot requires an extension of the classical elastica-
knot parameter space.
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Astrophysics of Galaxies
Where Do Quasars Live? DESI DR1 Constraints from PAC Measurements
Shanquan Gui, Kun Xu and Donghai Zhao
Quasar environments connect the growth of supermassive black holes, active
galactic nucleus feedback, and
galaxy evolution. Small-scale
quasar clustering probes the one-
halo regime and can test whether
quasar activity depends on central–satellite status. We seek to obtain precise small-scale measurements of
quasar environments at $0.8<z<1.0$ and use them to constrain the
quasar–
halo connection, particularly the relative probability for satellite subhalos and central
halos of the same
halo accretion mass to host a
quasar. We apply the Photometric Objects Around
Cosmic Webs (PAC) method to DESI Data Release~1
quasars and photometric
galaxies from the DESI Legacy Imaging Surveys DR9, measuring the excess projected surface density of neighbouring
galaxies around
quasars, $\bar{n}_{2}w_{\rm p}$, down to a
stellar mass of $M_{\ast}=10^{10.80}M_{\odot}$ over $0.1<r_{\rm p}/(h^{-1}\,\mathrm{Mpc})<15$. we jointly model the excess surface-density measurements, the
quasar and luminous red
galaxy (LRG) autocorrelation functions, and the
quasar–LRG cross-correlation. We interpret these measurements using an N-body simulation together with a
stellar-to-
halo mass relation, an explicit
stellar-mass-incompleteness model, and a Gaussian
quasar occupation as a function of
halo accretion mass. The Gaussian
quasar occupation peaks at $\log_{10}(M_{\rm acc}/h^{-1}M_{\odot})=12.88^{+0.02}_{-0.02}$ with width $\sigma_{\rm q}=0.51^{+0.02}_{-0.01}$, and the relative satellite-hosting parameter, $B$, defined as the
quasar-hosting probability of a satellite subhalo relative to that of a central
halo at fixed
halo accretion mass, is $B=1.01^{+0.03}_{-0.03}$. Within the adopted model framework,
quasars are consistent with being equally likely to reside in central
halos and satellite subhalos at fixed
halo accretion mass. PAC has strong potential to deliver precise small-scale measurements of
quasar environments.
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Optics
Towards on-chip nascent all-van-der-Waals polarization optical components for nanoscale photonic applications
Dmitrii Litvinov, Ilia Begichev, Iakov Reznikov et al. (+8 more)
The integration of polarization-control elements into nanoscale photonic
circuits remains a central challenge for modern on-chip optical technologies, which call for continuous miniaturization. Van der Waals (vdW)
crystals provide a versatile platform for the creation of such components owing to their strong optical anisotropy, high-refractive indices and atomically precise
heterostructure assembly capabilities. In this work, we demonstrate an approach towards the creation of all-vdW on-chip polarization optical components, exemplified with quarter-wave plates operating in the near-infrared (NIR) spectral region, realized in specifically twisted ReSe2/alpha-MoO3 vdW
heterostructures on a Si/SiO2 platform. Here, low-
symmetry ReSe2 layer serves as a source of exceptionally high linearly polarized excitonic emission, whereas in-plane birefringent alpha-MoO_3 provides polarization-state conversion. Furthermore, our finite-difference time-domain (FDTD) simulations quantitatively reproduce the experimental observations with high accuracy revealing the critical roles of layer thicknesses, twist-angle, Fabry-Perot interference and emitter distribution effects in the determination of polarization conversion efficiency, which yields up to 95 % degrees of circular polarization (DoCP) for the optimized parametrization. Our findings establish a practical route towards fully integrated all-vdW polarization optical components, providing a foundation for nanoscale photonic architectures based entirely on layered materials.
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All authors Dmitrii Litvinov, Ilia Begichev, Iakov Reznikov, Changyi Chen, Maksim Sargsyan, Sergey Y. Grebenchuk, Makars Siskins, Kostya S. Novoselov, Alexey I. Berdyugin, Maciej Koperski, Davit A. Ghazaryan
High Energy Astrophysical Phenomena
On the astrophysical origin of cosmic rays: Constraining the Ultra-High-Energy Cosmic Ray Horizon through Nearby Galaxy Distributions
F. Dávila-Kurbán, F. Duplancic and D. Garcia Lambas
The origin of ultra-high-energy
cosmic rays (UHECR) remains a central open problem in astroparticle physics. The observed large-scale anisotropy of UHECR arrival directions above several EeV, together with the spectral suppression at the highest energies, suggests extragalactic sources confined to a limited volume of the nearby Universe, though the effective spatial scale of this contribution remains poorly constrained. We aim to constrain the effective propagation horizon of UHECR with energies E >= 8 EeV by studying how well the observed large-scale anisotropy is reproduced by the distribution of nearby
galaxies at different distances, accounting for
Galactic magnetic-field deflections. We construct volume-limited
galaxy samples from the GLADE+ catalogue extending to 10000 km/s (~150 Mpc) and use both dipole comparisons and angular cross-correlation analyses with the Pierre Auger Observatory UHECR flux map (E >= 8 EeV) to characterize the distance dependence of the anisotropy signal, further weighting the
galaxy-UHECR correlations using deflection maps derived from a
Galactic magnetic field model. We find that the angular separation between the
galaxy and UHECR dipoles is minimized for
galaxies within cz < 4000 km/s (< 60 Mpc), where the
galaxy dipole amplitude is also maximal. The
galaxy-UHECR cross-correlation signal is dominated by this nearby population and weakens rapidly at larger distances. Accounting for
Galactic magnetic field deflections enhances the correlation amplitude by more than a factor of two, indicating that
magnetic effects significantly shape the observed anisotropy. Our results indicate that the observed anisotropy of UHECR of 8 EeV and above is primarily driven by sources within ~50-60 Mpc, consistent with expectations from energy losses and
magnetic deflections, retaining a measurable imprint of the nearby extragalactic matter distribution.
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Earth and Planetary Astrophysics
Onset of dynamo action in planetesimals
Ludovic Huguet, Jonathan E. Mound, Christopher J. Davies et al. (+1 more)
Several meteorites have been found to carry primary remanent magnetizations imparted by fields generated within planetesimal cores during the early
solar system. Thermal
evolution models have shown that thermal convection likely drove the dynamo in the early
evolution of these bodies. In such small cores, the
magnetic Reynolds number is thought to be close to the threshold for dynamo action. However, the critical value of the
magnetic Reynolds number, meaning its value at the onset, is also poorly constrained in dynamo simulations. We perform dynamo simulations to investigate the onset of the dynamo at different Ekman ($E$) and
magnetic Prandtl ($Pm$) numbers, in a quasi-full sphere. Along two empirical paths in this $(E,Pm)$ space, the onset of dynamo action depends on whether the
magnetic field is initially strong or weak. The onset of the dynamo occurs at larger supercriticality (ratio between the Rayleigh number ($Ra$) and its critical value ($Ra_c$)) when moving toward more realistic parameter values. Once extrapolated to planetesimal core conditions, the supercriticality for the onset of the dynamo is about $10^3$ for a strong initial
magnetic field (meaning
magnetic energy is of the same order of magnitude or larger than the kinetic energy). For a weak initial field, the required $Ra/Ra_c$ would be larger. Compared to previous estimates, this revised criterion facilitates dynamo activity, and so extends the lifetime of the
magnetic field compared to previous models and allows the generation of a
magnetic field in smaller planetesimals.
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All authors Ludovic Huguet, Jonathan E. Mound, Christopher J. Davies, James F.J. Bryson
Quantum Physics
Deleterious effect of photon-phonon coupling on microcavities in their application as quantum sources
Y. Sacha C. L. S., G. C. Rickli, J. Dipold et al. (+4 more)
In
quantum systems, the contact with the environment is detrimental to the purity of the state, thus limiting the practical use of entangled sources in
quantum information applications. This loss of purity is observed in the form of additional noise in the
tomography of the state. We investigate this noise dependence in $Si_3N_4$ micro-cavities, previously used for
quantum state generation, and demonstrate that the dependence of this noise on the temperature is compatible with a coupling of the photonic chips to a thermal reservoir. The control of this noise source is a necessary condition for the efficient implementation of these devices as sources of entangled states in
quantum networks.
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All authors Y. Sacha C. L. S., G. C. Rickli, J. Dipold, R. A. Kögler, Paulo Nussenzveig, Nathália B. Tomazio, M. Martinelli
Mathematical Physics · Cross-listed from math.AP
Global Finite-Energy Weak Solutions and Sharp Entropy Decay for a Poisson-Nernst-Planck System with Interspecies Drag and Steric Effects
Baoli Hao, Fanze Kong, Kei Fong Lam et al. (+1 more)
We derive and analyze a binary Poisson-Nernst-Planck system with steric interactions and interspecies drag through the energetic variational approach. The steric effects are incorporated into the free energy, while the drag mechanism enters the dissipation functional; eliminating the transport velocities yields a non-diagonal, concentration-dependent Onsager mobility and an
entropy-production structure that is not coercive in the standard $L^2(0,T;H^1)$ sense. For the resulting drag-modified steric PNP system, we prove the existence of global finite-energy weak solutions using an
entropy-variable approximation, weighted gradient estimates, and a
vacuum-compatible square-root formulation of the weighted
entropy gradients. In the pure Neumann equal-mass setting, we establish a sublevel
entropy-
entropy production inequality, obtain exponential relaxation for approximation-generated weak solutions, and identify the sharp small-sublevel limit of the optimal
entropy-production constant through an explicit linearized formula involving the drag mobility, steric Hessian, Poisson coupling, and Neumann spectrum. We further show that the same linearized constant governs the local nonlinear relaxation of sufficiently small strong perturbations of the homogeneous
equilibrium. Finally, we discuss the rank-one steric limit and clarify the role of the positive definiteness of the steric
matrix in the finite-energy compactness theory.
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All authors Baoli Hao, Fanze Kong, Kei Fong Lam, Chun Liu
Astrophysics of Galaxies
SED Fitting of the Globular Clusters in Abell 2744 at z=0.3
Jinoo Kim and William E. Harris
We present a spectral energy distribution (SED) fitting analysis of globular cluster (GC) candidates in Abell 2744, a massive
galaxy cluster at
redshift z = 0.308 with a lookback time of 3.5 Gyr, using deep JWST/NIRCam photometry. By leveraging observations in eight broadband filters (F070W to F444W), we derive constraints on GC masses, ages, and
metallicities of 69 GC candidates, refining previous studies focused on color-magnitude analysis. The inferred GC masses predominantly fall near 10^7 M_sun, consistent with the high-mass end of typical GCs seen in the Local Group and overlapping with UCDs (Ultra-Compact
Dwarfs). Although the best-fit age estimates are unavoidably uncertain, we very tentatively identify two prominent concentrations: one at intermediate ages (4-6.5 Gyr) near [M/H]=-0.25; and a second at older ages 8 - 10 Gyr with both metal-poor ([M/H]=-0.66) and metal-rich ([M/H]=+0.15) components. As expected for broadband SED fitting, we find mass-age and age-
metallicity degeneracies in our result. Monte Carlo error propagation and tests with different SSP model assumptions show that the population-level trends in age and
metallicity are preserved, although individual age estimates must be interpreted with caution. The resulting mass-to-light ratios show wavelength dependence with a mild decline toward longer wavelengths and increase with age, while showing minimal sensitivity to
metallicity. These results demonstrate the power and current limitations of multi-band JWST SED fitting that highlight the potential of future JWST data for detailed characterization of GCs at lookback times of several Gigayears.
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Medical Physics · Cross-listed from cs.ET
Quantum Adaptive Sensing for Accelerated MRI
Asmit Ganguly, Suprajit Dewanji, Chenyang Zhao et al. (+1 more)
Compressed sensing accelerates MRI by reconstructing images from undersampled k-space, but performance depends strongly on sampling distribution. We propose an adaptive framework that selects Cartesian phase-encode lines sequentially using a fixed-cardinality quadratic unconstrained binary optimization (QUBO) formulation. The objective combines a preference for central k-space, signal-energy information from previously acquired measurements, and pairwise terms that encourage spatially dispersed sampling. The formulation is compatible with classical annealing and
quantum-annealing hardware. Retrospective experiments used simulated eight-coil 3D MRI data; QUBO problems were solved with parallel tempering, and images were reconstructed with SENSE and total-variation regularization. At 20% and 10% sampling, the proposed method improved PSNR, SSIM, NMSE, and HFEN compared with the evaluated static Cartesian strategies, including variable-density Poisson-disc sampling, although gains varied with resolution, acceleration, and noise level. In a reduced-pool experiment, a D-Wave
quantum-classical hybrid solver achieved reconstruction quality comparable to variable-density Poisson-disc sampling, demonstrating feasibility on current
quantum optimization infrastructure. While these results do not establish
quantum computational advantage, the direct QUBO representation provides a practical framework for adaptive MRI sampling and may benefit from future advances in
quantum-annealing hardware. Prospective scanner validation and systematic
quantum-classical benchmarking remain necessary.
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All authors Asmit Ganguly, Suprajit Dewanji, Chenyang Zhao, Danny J. J. Wang
Computational Physics
On the Removal of Solver-Induced Dependencies in Momentum-Weighted Interpolation for Primal and Continuous-Adjoint Flow Solvers
Niklas Kühl
Momentum-Weighted Interpolation (MWI) is a key component in pressure–velocity coupling schemes on collocated
cell-centered finite-volume methods for both primal and continuous adjoint formulations. In many practical implementations, MWI relies on diagonal momentum coefficients that include contributions from under-relaxation and time discretization. As a result, both primal quantities of interest and adjoint sensitivities may exhibit a non-physical dependence on solver parameters such as relaxation factors and time-step size, and no well-defined limit is obtained as these parameters approach zero. In this work, building on previous developments in discrete-consistent MWI formulations, a simple correction is proposed that removes solver-induced contributions from the diagonal momentum coefficients in the pressure-driven term. The resulting formulation preserves the original discretization while eliminating artificial dependencies on relaxation and time-stepping parameters and is applied consistently to both primal and adjoint systems. To facilitate its application, the derivation is presented in a structured, recipe-like manner that can be readily followed and transferred to different finite volume-based solver configurations. The proposed modification is assessed for a two-dimensional laminar cylinder flow and a three-dimensional turbulent ship hull flow configuration. In both cases, the uncorrected formulation leads to significant variations in forces, wake-related quantities, and shape sensitivities when solver parameters are altered, despite all simulations being iterated to converged residual levels and stable integral quantities. In contrast, the corrected formulation yields consistent results across a wide range of relaxation factors and time-step sizes.
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High Energy Physics (Theory)
Page transition for the complexity of an evaporating black hole
Violet Concepcion, Yasunori Nomura, Kyle Ritchie et al. (+1 more)
Recent results demonstrate that there exists a sharp, Page-like transition for the complexity of subsystems of Haar-random states as their fractional subsystem size surpasses one half. They further demonstrate that this transition also occurs for the
holographic complexity of boundary subregions of eternal AdS black holes, assuming the Complexity$=$Volume (CV) proposal for subregions. We interpret this transition as a crossover from spectrum-dominated to basis-dominated subsystem complexity, reflecting the breakdown of approximate thermality beyond half-system size. We then apply this
reasoning to an evaporating AdS black hole coupled to a bath, modeled by a
quantum circuit undergoing random
evolution on an interior subsystem of diminishing size. Using the basis-spectrum decomposition of subsystem complexity, we argue for a similar Page-like transition in the radiation complexity. We then show, using CV for subregions, that the same transition appears in the
holographic complexity of the radiation subsystem through the emergence of an island, whose volume gives the dominant contribution. We argue that the island volume contribution resolves an apparent complexity paradox analogous to the information paradox.
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All authors Violet Concepcion, Yasunori Nomura, Kyle Ritchie, Samuel Weiss
Earth and Planetary Astrophysics
JWST/MIRI Reveals the Evolution from Molecular to Atomic Disk Winds
Naman S. Bajaj, Ilaria Pascucci, Sylvie Cabrit et al. (+10 more)
The
evolution and dispersal of protoplanetary disks–governed by
accretion, magnetically launched jets and winds, and photoevaporative winds–fundamentally shape planetary systems. Determining how these mass-loss processes co-evolve is crucial for constraining
planet formation pathways. We analyze archival JWST/MIRI/IFU data of 72 inclined (i>40deg) mostly ClassII disks to identify and characterize spatially resolved jets and winds, focusing on [NeII] and H2 lines. Extended emission in H2 S(1), S(3), S(5), S(7) and/or [NeII] is detected toward 66 disks, revealing diverse morphologies. We develop a framework to identify conical H2 winds and high-velocity [NeII] jets perpendicular to the disk, detecting them toward 46 and 40 disks, respectively. All sources with [NeII] jets exhibit a corresponding wind traced in either H2 (85%) or [OI], establishing a connection between jets and winds. The detection fractions of [NeII]-jets and H2-winds correlate positively with mass
accretion rate, with no dependence on disk inclination or
stellar mass. Conversely, marginally resolved low-velocity [NeII] winds are found preferentially toward lower accretors. Among sources with H2 winds, detection of hotter winds traced by S(7) and S(5) declines more rapidly with decreasing
accretion rate than the colder S(1) component. Comparison with high-resolution [OI]6300\textÅ spectroscopy reveals [OI] LVC and extended H2 wind detections preferentially toward moderate-to-high accretors (>~10^{-8.5}~Msun/yr), whereas lower accretors exhibit only [OI] and [NeII] winds. Together, these results indicate that atomic jets and atomic+molecular winds, consistent with an MHD disk-wind origin, dominate during early, actively accreting disk phases, while at lower
accretion rates, jets weaken and winds become predominantly atomic.
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All authors Naman S. Bajaj, Ilaria Pascucci, Sylvie Cabrit, Suzan Edwards, Gabriele Cugno, Andrew D. Sellek, Joan R. Najita, Ke Zhang, Richard Alexander, Gregory J. Herczeg, Uma Gorti, Sophie C. Clark, Tracy L. Beck
Nuclear Theory
Deformation, halo, and bubble structure: A paradigm shift of exotic phenomena in light to medium mass nuclei
R. Barman, R. Chatterjee, W. Horiuchi et al. (+4 more)
The emergence of exotic
nuclear structures, such as deformation, one- and two-
neutron halos, and bubble configurations, marks a paradigm shift in our understanding of light- to medium-mass
nuclei far from stability, particularly near and within the island of inversion extending across $N=20-28$. In this review, we integrate microscopic structure calculations using the antisymmetrized molecular dynamics method with reaction theories such as the Glauber model for high-energy collisions, and highlight the use of the fully
quantum mechanical finite-range distorted wave Born approximation for calculating both inclusive and exclusive Coulomb breakup observables for these medium mass systems. These theoretical frameworks enable precise probing of
nuclear density profiles through observables such as total reaction cross sections,
neutron removal cross sections, relative energy spectra, parallel momentum distributions, and angular distributions. Applications to several
nuclei in the island of inversion reveal enhanced
halo extensions,
neutron-
neutron correlations in Borromean
nuclei, and central density depletions in bubbles, challenging traditional shell-model paradigms. Furthermore, the sensitivity of astrophysical reaction rates to these exotic inputs is explored, demonstrating their role in the refinement of r-process nucleosynthesis models and elemental abundance predictions. This unified approach not only bridges
nuclear structure and reactions, but also highlights the driplines as frontiers for unraveling
nuclear matter under extreme conditions, with implications for rare-isotope beam experiments and beyond.
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All authors R. Barman, R. Chatterjee, W. Horiuchi, M. Kimura, G. Singh, Jagjit Singh, Shubhchintak
Lattice Field Theory
Dibyendu Bala, Olaf Kaczmarek, Sayantan Sharma et al. (+1 more)
We calculate the
spin-dependent potential, which is the $\mathcal{O}(1/M^2)$ correction term to the thermal potential between a static
quark-antiquark pair within non-relativistic QCD. At leading order in hard thermal loop perturbation theory, we show that this
spin-dependent potential has an imaginary part which is different in magnitude for pseudoscalar and vector quarkonium states. For the first time, we extract the imaginary part non-perturbatively using
lattice techniques, in the deconfined phase of quenched QCD at $T\sim 470$ MeV, after performing a continuum estimation and subsequent renormalization. We have found that the
spin-dependent potential in the
quark-
gluon plasma phase is complex, and its imaginary part has a remarkably significant contribution over the thermal static potential for charmonium states. Consequences of this thermal
spin-dependent potential on the quarkonium spectral functions are also discussed.
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All authors Dibyendu Bala, Olaf Kaczmarek, Sayantan Sharma, Swagatam Tah
Quantum Physics
Quantum Cellular Automata from Kramers-Wannier Dualities and Modular Relations
Carolyn Zhang and Po-Shen Hsin
Recent work has constructed higher-dimensional analogs of non-invertible
symmetries similar to 1+1d Kramers-Wannier duality. Although their continuum descriptions often treat purely gravitational topological terms as inessential counterterms, these terms can have an essential
lattice manifestation: they distinguish states prepared by finite-depth
quantum circuits (FDQCs) from those entangled by nontrivial
quantum cellular automata (QCAs). Motivated by this mismatch, we show that QCAs associated with gravitational topological responses arise in several related settings: (1)
lattice realizations of projective $\mathrm{SL}(2,\mathbb{Z}_N)$ relations generated by topological operations on
symmetries; (2) squares of dualities that generalize the relation between fermionization and Kramers-Wannier duality; (3)
lattice implementations of QCAs through higher-form gauging; and (4) invertible phases protected by generalized time-reversal
symmetries. We derive new projective $\mathrm{SL}(2,\mathbb{Z}_N)$ relations whose projective phases are gravitational topological responses constructed from Stiefel-Whitney classes. We furthermore give a general protocol for preparing the associated QCA-entangled states using finite-depth
unitary circuits, measurements, and error correction. These results unify the study of gravitational topological responses in field theories, higher dimensional dualities, and
quantum cellular automata.
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Materials Science
Ionic Diffusion Properties of Rare-Earth High-Entropy Oxides from a Machine-Learned Interatomic Potential
Mary Kathleen Caucci, Billy E. Yang, Saeed S.I. Almishal et al. (+2 more)
Rare-earth high-
entropy oxides (RE-HEOs) have emerged as a promising class of functional ceramics for solid-state electrochemical applications due to their chemical complexity, structural tunability, and potential for fast oxygen-ion transport. In this work, we investigate oxygen
diffusion in ceria-based RE-HEOs of the form Ce$_x$(YLaPrSm)$_{1-x}$O$_{2-\delta}$ using classical molecular dynamics simulations driven by the
Crystal Hamiltonian Graph Neural Network (CHGNet) machine-learned interatomic potential. To improve predictive accuracy for lanthanide-containing systems, we
benchmark three CHGNet variants, including a fine-tuned r$^2$SCAN-trained model, against targeted density functional theory (DFT) data that explicitly include f-valence electrons. Simulations across temperature, Ce content, oxygen vacancy concentration, and both fluorite and bixbyite structures reveal that oxygen transport in RE-HEOs is governed by the interplay of two factors: the concentration of mobile vacancies and the local cation environment through which they hop. At fixed composition, ionic conductivity exhibits a non-monotonic dependence on vacancy concentration, with optimal
diffusion occurring at moderate vacancy levels and reduced mobility at higher concentrations. Increasing Ce content lowers migration activation energies and enhances diffusivity through low-barrier
diffusion networks built from Ce-Ce and Ce-Y edges. Analysis of individual oxygen hopping events provides atomistic insight into how local chemical environments and short-range cation ordering govern transport in high-
entropy oxides. Overall, this work demonstrates that machine-learned interatomic potentials can resolve composition-structure-transport relationships in chemically complex
oxides, and identifies active pathways through which compositional tuning can enhance oxygen-ion conductivity in RE-HEO materials.
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All authors Mary Kathleen Caucci, Billy E. Yang, Saeed S.I. Almishal, Jon-Paul Maria, Susan B. Sinnott
Optics
How to calculate the Wigner angle
C. J. McKinstrie and M. V. Kozlov
Lorentz transformations in time and two space dimensions consist of boosts and rotations, and combinations thereof. In general, the combination of two boosts is not another boost: It is a boost followed by a rotation. The rotation angle is called the Wigner angle. Although it is straightforward to determine the energy and direction of the combined boost, it is difficult to determine the Wigner angle. In this article, the vector,
matrix and spinor derivations of formulas for the Wigner angle are reviewed, and the underlying mathematics and physics are discussed briefly. Although the derivations are different, the results they produce are equivalent, as they should be. Like many physics problems, if one looks at the problem in the right way, it is not difficult to solve.
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Plasma Physics
A Multi-Species Reactive-Boltzmann Formulation for Self-Consistent Kinetic Simulation of Burning Fusion Plasmas
Mark Dunn, Jingwei Hu and Uri Shumlak
Discrepancies between experimental data and radiation-hydrodynamic models of burning
plasmas at the National Ignition Facility have been attributed, in part, to possible deviations of reactant ion distributions from Maxwellian
equilibrium. In particular, it has been hypothesized that the collisional relaxation of energetic fusion products with the bulk
plasma may generate suprathermal ion populations not captured by reduced models. To assess this hypothesis in a fully kinetic setting, we present a multi-species reactive–elastic kinetic framework, in which fusion sources and sinks are evaluated directly from the reactant velocity distribution function with a reactive Boltzmann collision operator. For computational efficiency, elastic interactions are modeled in the small-angle collision limit using the Landau and Lenard–Bernstein collision operators, although the framework admits large-angle elastic scattering generalizations. The integro-differential collision operators are discretized with a fast
Fourier spectral method, enabling efficient, high-order accuracy evaluation of reactive processes in three-dimensional velocity space and providing a deterministic alternative to Monte Carlo collision methods. Numerical experiments are performed for spatially homogeneous two- and three-species D–D fusion systems in weakly coupled, early-time regimes. We find that fusion product heating does not generate a significant suprathermal population in the reactant ions: deviation from the corresponding Maxwellian distribution remains small in both the Frobenius norm and the fusion reactivity.
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General Relativity and Quantum Cosmology
Gravitational Lensing in a Kasner Background: Distinguishing Wormholes and Black Holes
Celio R. Muniz, Jonathan A. Rebouças, M. B. Cruz et al. (+1 more)
We investigate gravitational
lensing by compact objects embedded in anisotropic Bianchi-I cosmologies using directional Jacobi maps within the thin-lens approximation. The formalism is developed for a general diagonal Bianchi-I spacetime and specialized to the Kasner solution as an analytically tractable background. Using the Ellis–Bronnikov wormhole and the Schwarzschild black hole as representative lenses, we derive anisotropic lens equations, characteristic axis-aligned
lensing scales, and the corresponding critical curves. We show that the directional splitting of the characteristic scales depends on the complete source–lens–observer optical propagation and provides a
geometric probe of anisotropic expansion independent of the overall lens scale. By contrast, the exact critical curves exhibit a much weaker deformation, indicating that characteristic-scale splitting and critical-curve morphology probe distinct aspects of the lens mapping. The comparison between wormhole and black-hole lenses further reveals that identical anisotropic backgrounds are filtered differently by distinct weak-field deflection laws. These results provide a simple framework for disentangling cosmological anisotropy from the local geometry of compact lenses.
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All authors Celio R. Muniz, Jonathan A. Rebouças, M. B. Cruz, R. M. P. Neves
Astrophysics of Galaxies
Outflows in a super-Eddington quasar drive clumpy circumgalactic medium and extended H$\alpha$ nebulae at $z \gtrsim 6$
Lucas Tortora, Tiago Costa, Debora Sijacki et al. (+1 more)
The discovery of gargantuan black holes with masses exceeding a billion
solar masses at $z\gtrsim6$ suggests rapid black hole growth and significant energy input into their host
galaxies in the early Universe. With JWST probing previously unseen phases of the interstellar (ISM) and circumgalactic (CGM) medium around $z > 6$
quasars, detailed theoretical studies can now be directly confronted with observations. We use zoom-in simulations of a massive protocluster at $z\sim6$, employing both the fiducial FABLE
galaxy formation model and modifications that allow earlier black hole seeding and mildly super-Eddington
accretion. The central
quasar remains Compton-thick throughout most of its
evolution, with the obscuration arising from the ISM of its compact host
galaxy. The onset of sufficiently strong
quasar feedback drives a 'blow-out' episode, clearing out escape channels for ionizing radiation and leaving the central engine unobscured. This leads to a complete transformation of the CGM, whereby powerful, metal-enriched
outflows produce a population of cold, fast, neutral clumps, significantly increasing the covering fraction of neutral hydrogen in the host
halo. Radiative transfer calculations performed with a new ray-tracing code show that the CGM responds to
quasar activity through the formation of H$\alpha$ nebulae, whose size and luminosity increase with the strength of
quasar feedback and decrease with obscuration level. Enhanced early black hole growth thus fundamentally reshapes the ISM and CGM of $z\sim6$
quasars, leaving clear observable signatures in their obscuration, neutral hydrogen distribution, and extended H$\alpha$ emission.
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All authors Lucas Tortora, Tiago Costa, Debora Sijacki, Jake S. Bennett
Quantum Physics
Electron shuttling as a probe for charge defects
Hamza Jnane, Tamas Daniel Lipovics and Guido Burkard
Silicon
spin qubits are a leading platform for scalable
quantum computing, but their performance is limited by charge noise, widely attributed to two-level fluctuators (TLFs). The location of individual TLFs is generally unknown, and existing methods to localise them does not scale favourably with device size. Here, we show that electron shuttling turns a single mobile
spin into a scanning probe of individual defects. We show that by shuttling a
spin over a range of distances and tracking its coherence loss, one can localise defects along the channel and constrain their switching rate and fluctuation amplitude. Because one shuttled electron sweeps an extended region, the approach scales more favourably than previous methods. Our protocol requires no additional hardware and provides a practical route to mapping the charge-defect landscape of large silicon devices, enabling defect-aware calibration and avoidance in shuttling-based architectures.
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Astrophysics of Galaxies
Megaparsec-Scale Neutral Hydrogen Flows in the Neighborhood of Hickson Compact Group 100
Qingzheng Yu, Taotao Fang, Enrico M. Di Teodoro et al. (+2 more)
The
evolution of
galaxies is strongly influenced by their ability to exchange gas with their surroundings, yet direct observational constraints on these processes remain scarce. Using ultra-deep neutral hydrogen (HI) observations with the Five-hundred-meter Aperture Spherical
Telescope (FAST), we detect a diffuse HI structure extending over $\sim$1 Mpc around the compact
galaxy group HCG 100, with integrated column densities down to $\sim$$8.6\times10^{17}$ cm$^{-2}$. This structure is among the most extended and lowest-density neutral gas systems ever observed in emission. The HI gas forms a coherent envelope connecting the compact group to neighboring
galaxies and shows a large-scale coherent velocity gradient around HCG 100 extending across $\sim$0.6 Mpc. The extended structure contains $\sim$$1.4\times10^{10}$ $M_\odot$ of diffuse neutral gas, implying that up to $\sim$40$-$50% of the HI gas resides outside
galaxies. Such a large diffuse HI structure may arise either from large-scale
tidal debris or gas
accretion from the surrounding
cosmic web. Our results demonstrate that massive reservoirs of diffuse neutral gas can persist on megaparsec scales around
galaxy groups for extended periods, providing a previously unseen component of
baryon cycling in dense environments.
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All authors Qingzheng Yu, Taotao Fang, Enrico M. Di Teodoro, Cheng Cheng, Cong Kevin Xu
Instrumentation and Methods for Astrophysics
Low-cost, ultra-wideband, differential low-noise amplifier for interferometric radio telescopes
Sophia Da Costa, Albert Wai Kit Lau and Keith Vanderlinde
We present a low-cost, ultra-wideband, dual-polarized differential low-noise amplifier that eliminates the need for a pre-amplification balun. Built entirely from commercial surface-mount components, the design costs approximately 20 US dollars per unit. The amplifier has been characterized through laboratory gain and noise measurements together with feed-coupled hot-cold testing at the Dominion
Radio Astrophysical Observatory. A noise figure close to 0.3 dB is demonstrated across a 10:1 bandwidth when matched to a constant 130 $\Omega$ source, while feed-coupled measurements yield system noise temperatures as low as 25 K when matched to a Vivaldi feed operating over a 300-1500 MHz bandwidth.
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General Relativity and Quantum Cosmology
Viscosity effects on the shadow of a non-rotating black hole
Sayantani Lahiri, Sergio Gimeno-Soler, Alejandro Cruz-Osorio et al. (+2 more)
We study the effect of shear viscosity in stationary magnetized
accretion tori on synthetic images of non-rotating black hole shadows. Shear viscosity and spacetime-
curvature contributions are introduced perturbatively in the
tori through first and second-order transport coefficients within a second-order causal theory of non-ideal relativistic hydrodynamics. Synthetic black hole shadow images at 230\,GHz are obtained via general relativistic radiative transfer computations assuming thermal synchrotron emission and for a wide range of
plasma magnetization parameters, viewing inclination angles, electron-temperature prescriptions, and viscosity parameters. A comparative pixel-by-pixel analysis using two normalized metrics shows that the largest image differences occur for strongly magnetized
tori. While shear viscosity induces only minor changes in the overall shadow morphology, its combined effects with spacetime
curvature are more evident in localized modifications of the synchrotron emission and pixel-wise flux distribution. These effects become increasingly pronounced at higher inclination angles, with the largest brightness differences between viscous and non-viscous configurations occurring for larger values of the electron-temperature parameter. Overall, our results indicate that shear viscosity and spacetime
curvature leave only modest imprints on black hole shadow images produced by stationary thick disks, with differences remaining at the level of a few $\mu$Jy. Since our analysis is limited to stationary
tori, the effects of shear viscosity might however be more significant in fully dynamical
accretion systems.
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All authors Sayantani Lahiri, Sergio Gimeno-Soler, Alejandro Cruz-Osorio, José A. Font, Ziri Younsi
High Energy Physics (Phenomenology)
ALP pair production at the LHC
Ilaria Brivio, Simone Meoni and Davide Pagani
We study
axion-like particle (ALP) pair production at the LHC, investigating its sensitivity to the simultaneous presence of dimension-5 and dimension-6 ALP interactions. Focusing on the signature with four isolated
photons, we analyze for the first time the non-resonant process $gg\to aa$, finding that it can constrain significantly ALP interactions, already at an integrated luminosity of 300 fb$^{-1}$. Particular
attention is paid to the multidimensional nature of the ALP parameter space. To this end, we present a re-interpretation of a search for the
Higgs-resonant process $gg\to h\to aa$ by the ATLAS Collaboration, recasting their results within a three-parameter space. We find that the multi-dimensional constraints resulting from both non-resonant and
Higgs-resonant ALP pair production exhibit non-trivial features, that are expected to extend to other searches in which the ALPs decay into Standard Model particles.
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