High Energy Astrophysical Phenomena
Little Red Dots as Supermassive Counterparts of SS 433: A Hyper-Eddington Accretion Framework
Shuying Zhou, Mouyuan Sun, Xihan Ji et al. (+11 more)
High-
redshift little red dots (LRDs) are compact sources characterized by V-shaped spectral energy distributions (SEDs), broad emission lines, and often prominent Balmer breaks. Their high number density and apparently large black hole masses suggest that they are essential to the early
evolution of
galaxies and supermassive black holes (SMBHs); however, the nature of their central engines remains uncertain. Here, we propose that LRDs are the supermassive, high-
redshift counterparts of the hyper-Eddington accreting
Galactic microquasar SS~433, viewed at high inclinations. By scaling the hyper-Eddington
accretion physics from
stellar-mass black holes to supermassive scales, we show that the observed LRD features, including X-ray weakness, soft optical SEDs, apparent sub-Eddington
accretion ratio, and Balmer breaks, emerge naturally from the self-shielding geometry of a puffed-up
accretion disk. In this framework, the broad-line regions are ionized by anisotropic radiation escaping from the inner disk, analogous to the unseen UV/X-ray emission revealed by the W50 nebula in SS 433. Their low-inclination or lower-
accretion-rate counterparts would appear as little blue dots (LBDs) or normal active
galactic nuclei. Our model predicts that the Balmer break strength positively correlates with the broad-line width, that the emission lines are more variable than the optical continuum, that LRDs are intrinsically more luminous than observed, and that LBDs are more variable than LRDs. This unified-scale model redefines LRDs as the essential laboratories for observing the rapid
accretion-driven growth that shaped the early assembly of
galaxies and their central SMBHs.
Read the full abstract ▾
All authors Shuying Zhou, Mouyuan Sun, Xihan Ji, Ya-Ping Li, Luis C. Ho, Roberto Maiolino, Zhen-Yi Cai, Hai-Cheng Feng, Manqi Fu, Wei-Min Gu, Tong Liu, Junfeng Wang, Jianfeng Wu, Yongquan Xue
Statistical Mechanics
Asymptotic hydrographs and anomalous dispersion in mass-conserving storage cascades
Henrique Santos Lima, Márk Honti and Balázs Sándor
Sums of independent exponential random variables lead to the Erlang distribution, providing a direct probabilistic route from exponential waiting times to the integer-shape gamma law. This paper investigates how this classical construction changes when the exponential waiting-time density is replaced by the $q$-exponential density of nonextensive statistics. Our main result is an analytical asymptotic expression for the
outflow of a mass-conserving cascade of reservoirs driven by a $q$-exponential waiting-time kernel. In the critical case $q=5/3$, the large-cascade flow rate converges to a stable Lévy density whose time argument is shifted by a Galilean-type transformation. This shifted Lévy law gives the asymptotic hydrograph of the cascade. We also found that for the entire regime $1<q<2$ the macroscopic dynamics are governed by $\alpha$-stable Lévy laws. This proves that anomalous non-Gaussian dispersion can emerge from pure mass-conserving convolutional chains without invoking fractional derivatives.
Read the full abstract ▾
High Energy Physics (Experiment)
Analysis note: Long-range near-side correlation in $e^+e^-$ with $W$-boson-pair events at 183-209 GeV with ALEPH archived data
Tzu-An Sheng, Yu-Chen Chen, Yi Chen et al. (+12 more)
Events characterized by a high multiplicity of charged particles have been a central focus in the study of collective behavior across both large and small collision systems. A previous measurement of two-particle angular correlations in $e^+e^-$ collisions at center-of-mass energies up to $\sqrt{s} = 209$ GeV, using LEP2 data, revealed discrepancies with Monte Carlo (MC) predictions at high multiplicity, suggesting the possible emergence of long-range near-side correlations even in the simplest collision system. Unlike at lower energies, where
quark-antiquark production dominates, $W^+W^-$ processes become increasingly important at multiplicities above 30. On the one hand, the observed excess in long-range correlations may reflect the more complex color-string configurations arising from $W^+W^-$ production. On the other hand, it can simply arise from the higher final-state multiplicity made possible by the increased collision energy, independent of the underlying production mechanism. To discriminate between these competing interpretations, we present a measurement of two-particle angular correlations in $e^+e^-$ collisions at $\sqrt{s} = 183-209$ GeV, with a focus on enhancing the contribution from $W^+W^-$ processes. The analysis uses data collected by the ALEPH detector during the LEP2 program. Correlation functions are evaluated across a broad range of pseudorapidities and full azimuth, in bins of charged-particle multiplicity. A ridge-like modulation is seen for multiplicity above 50, deviating from the MC reference. In addition, the correlation functions are further decomposed into a
Fourier series, and the resulting harmonic coefficients $v_n$ are compared with predictions from the archived Monte Carlo sample. For multiplicity starting from 30, the signed $v_2$-like proxy goes from negative to positive, also deviating from the MC baseline.
Read the full abstract ▾
All authors Tzu-An Sheng, Yu-Chen Chen, Yi Chen, Kyle Sun, Jason Chiu, Michael Peters, Marcello Maggi, Austin Baty, Anthony Badea, Chris McGinn, Jesse Thaler, Gian Michele Innocenti, Jingyu Zhang, Paoti Chang, Yen-Jie Lee
Plasma Physics
Wave-Energy Partition Governs Weak Collisional Damping in Cold Plasmas
Yanzeng Zhang, Xingming Zeng, Xianzhu Tang et al. (+1 more)
Weak dissipation can control wave propagation, mode competition, and instability thresholds in
plasmas, yet the physical origin of large branch-to-branch differences in collisional damping is often obscured by dielectric-tensor calculations. We show that weak collisional damping in cold
plasmas is governed by wave-energy partition. In the one-rate cold-
plasma model, the damping rate of a collisionless eigenmode is exactly the collision frequency multiplied by the fraction of the total wave energy stored in
plasma motion. This result recasts the standard perturbative damping formula into a compact and physically transparent law, immediately explaining why field-dominated branches such as whistlers can be much less damped than the collision frequency, whereas quasi-electrostatic modes can exhibit damping of comparable magnitude. Analytic examples for Langmuir, transverse electromagnetic, whistler, and extraordinary waves show that the energy-partition form classifies weak collisional damping across distinct branches and provides a simple diagnostic for mode competition in multibranch
plasma-wave systems.
Read the full abstract ▾
All authors Yanzeng Zhang, Xingming Zeng, Xianzhu Tang, Ge Zhuang
High Energy Physics (Theory)
Kosei Fujiki, Jonathan Harper, Tadashi Takayanagi et al. (+1 more)
In this work we consider a particular codimension-1 region of a
holographic spacetime which we call the
entanglement wedge polygon (EWP). For a pure state and a partition of the boundary into a number of regions $A_i$ the EWP is defined as the region external to all the individual homology regions $r_{A_i}$ which consists of the intersection of the
entanglement wedge EW($A_i$) with the time slice. In
vacuum AdS$_3$ and BTZ spacetime, the quantity is topological as a direct consequence of the Gauss-Bonnet
theorem. In higher dimensions we make progress by considering a number of concrete examples including
vacuum, black brane, and
soliton solutions of AdS$_{d+1}$ as well as spacetime geometries with end of the world branes dual to boundary conformal field theories. We provide a suitable generalization to mixed states and comment on possible connections between the EWP and measures of multi-partite
entanglement.
Read the full abstract ▾
All authors Kosei Fujiki, Jonathan Harper, Tadashi Takayanagi, Nicolò Zenoni
High Energy Physics (Theory)
Zi-Hao Li and Run-Qiu Yang
The
holographic time-like
entanglement entropy (TEE) extends
entanglement to time-like boundary subregions. While its definitive
holographic dictionary remains debated, one concrete proposal utilizes piece-wise extremal surfaces. In this work, we adopt this
geometric prescription as an exploratory framework to holographically investigate the late-time ($\tau_0\to \infty$) growth of TEE in asymptotically AdS black holes with a space-like singularity and no inner horizon. By assuming a Kasner geometry near the space-like singularity and using the null energy condition, we analytically show that a critical extremal surface $\mathcal{A}_c$ inside the event horizon completely governs the late-time linear growth of the TEE. This result suggests that the late-time behavior of TEE is tightly constrained by the geometry of black hole interiors. While the dominant energy condition (DEC) guarantees an upper bound for the real part's growth rate, we
conjecture a corresponding universal lower bound for the imaginary part. Numerical results from Einstein-scalar theory demonstrate the robustness of this bounding behavior: the
vacuum Schwarzschild-AdS geometry consistently maximizes the real growth rate and minimizes the imaginary part, suggesting these bounds hold in broader
holographic setups.
Read the full abstract ▾
General Relativity and Quantum Cosmology
Population-level correlations in Bayesian statistics: an illustrative model for gravitational-wave astronomy
Caroline B. Owen, Alexandre Toubiana and Davide Gerosa
With increasingly large numbers of gravitational-wave events, population inference is now beginning to move beyond predictions of marginal distributions and to probe correlations between compact-binary parameters such as masses,
spins, and
redshifts. These correlations have strong constraining power for both astrophysics and tests of general relativity. In this paper, we present an idealized analytical model to study the interplay between single-event correlations, systematic biases, and population-level correlations. With this, we investigate the potential emergence of false-positive measurements of population-level correlations. We quantify how the presence of correlations at the single-event level between a pair of parameters increases the uncertainty of population-level correlations for those parameters, potentially obscuring the true underlying population correlation if present. We also find that if waveform systematics lead to biases that are correlated across the catalog (which is likely, because certain regions of the parameter space are more difficult to model), this can be effectively absorbed by a population analysis that targets correlations and can be misinterpreted as such. This simple Gaussian-based model may serve as a broad compass for future, more detailed explorations.
Read the full abstract ▾
Quantum Physics
Finite-Time Electrometry with a Quantum-Regime Single-Ion Phonon Laser
Pei-Dong Li, Yuan-Zhang Dong, Zhuo-Zhu Wu et al. (+6 more)
The
phonon laser realized in a trapped ion, i.e., a self-sustained mechanical oscillator, has demonstrated the unique characteristics in practically detecting externally applied electric signals without the prerequisite of sideband cooling. Entering the
quantum regime via sideband cooling is expected to further improve its sensing performance. Here we report the first experimental realization of a
quantum-regime single-ion
phonon laser ($\bar{n}<10$) using a trapped $^{40}\mathrm{Ca}^+$ ion and demonstrate electrometry based on its phase-space
symmetry-breaking response to weak resonant electric fields. By tuning the
phonon-
laser parameters, we reveal that the sensing performance is fundamentally governed by the finite-time relaxation dynamics of the underlying open
quantum system. We find that a slow Liouvillian relaxation, correlated with the finite experimental interaction window, effectively enhances the dynamic susceptibility while maintaining the structural robustness of the limit cycle. This regime, when applied to the detection of electric fields, produces a shot-noise-limited peak sensitivity of $14.15 \pm 0.77~\mu\mathrm{V/m}/\sqrt{\mathrm{Hz}}$ and a minimum detectable field variation of $\delta E_{\mathrm{min}} \approx 1.83~\mu\mathrm{V/m}$. Our results establish
quantum phonon lasers as a practical platform for advanced sensing and highlight the central role of Liouvillian dynamics in non-
equilibrium electrometry.
Read the full abstract ▾
All authors Pei-Dong Li, Yuan-Zhang Dong, Zhuo-Zhu Wu, Jia-Wei Wang, Ji Li, Jian-Qi Zhang, Zhi-Jiao Deng, Liang Chen, Mang Feng
Mesoscale and Nanoscale Physics
Propagating edge and interfacial states in corrugated graphene: Robustness and configurability
Adel Belayadi, Dawei Zhai and Nancy Sandler
Periodically strained
graphene provides a versatile platform to realize moiré-like electronic structures. We show that the interplay between strain-induced pseudomagnetic field and a displacement-field-controlled scalar potential enables the formation of isolated narrow bands. Some of the low-energy bands are topological, carrying valley-opposite Chern numbers. Remarkably, despite a vanishing total Chern number, propagating in-gap edge states emerge in various nanoribbon geometries that preserve valley
symmetry. We elucidate the distinct mechanisms responsible for edge states in the zero-energy and higher-energy gaps and demonstrate their robustness against disorders, despite lacking conventional topological protection. Leveraging these properties, we propose device architectures in which a displacement field switches the zero-energy gap and its associated edge channels on and off. Furthermore, split-gate geometries generate topological interfacial states that coexist with the edge modes and can be spatially reconfigured. These results establish strain superlattices as a powerful platform for engineering topological electronic states and electronic transport.
Read the full abstract ▾
Optics
Boundary-conformal integration for the invariant-imbedding T-matrix method: high-order convergence for faceted particles
Zihua Wu and Yu Xiong
The invariant-imbedding T-
matrix method (IITM) is a standard tool for light scattering by large, sharply faceted, non-axisymmetric particles (atmospheric ice
crystals and mineral
dust) where the surface-based extended boundary condition method loses accuracy. Its accuracy is limited by "staircasing": the dielectric contrast of a faceted particle is integrated across boundaries that cut the quadrature grid, so standard quadrature converges at low algebraic order. We show that this non-smoothness has a single
geometric origin, the tangencies of the integration sphere to the faces and edges of the particle, which produce jumps, kinks, and half-integer branches according to the tangency type, in all three integration directions. A boundary-conformal scheme removes them using closed-form azimuthal coefficients, panel splitting at the analytically known tangency loci, and a square-root substitution $x \mapsto x_c + t^2$ that absorbs the half-integer branches. For a hexagonal prism the azimuthal integration becomes exact and the zenithal and radial directions recover spectral and fourth-order convergence; because the construction depends only on the contact geometry, it extends to any convex polyhedron, demonstrated on the solid hexagonal bullet (a faceted ice habit with tilted faces). The zenithal crossing is a square-root branch rather than a kink, so the established interval-splitting alone gives only $\mathcal{O}(N^{-3})$, while the radial step removes the half-integer edge branch that caps the Riccati recurrence on faceted particles. The convergence orders are fixed by the local contact geometry and verified size-independent up to $k\,r_{\max} = 20$; what grows with size is the resolution needed to reach each asymptotic regime, not the order.
Read the full abstract ▾
Mesoscale and Nanoscale Physics
Mechanically Exfoliated Metallic Delafossite PdCoO2 Nanomembranes: Quantum Transport and Electrical Evaluation Toward Interconnect Applications
Chengyu Zhu, Pahuni Jain, Yi Zhang et al. (+6 more)
Metallic delafossite
oxides have drawn
attention for their ultralow resistivity and coherent electronic transport. However, mesoscopic transport studies are hindered by the limited access to high quality nanoscale devices. Here, we report single crystalline PdCoO2 nanomembranes, enabling exploration of quasi two dimensional (2D) transport. Shubnikov de Haas and Aharonov Bohm oscillations under different
magnetic field orientations are observed at low temperatures, from which the electron effective mass and electron phase coherence length are extracted. Beyond
quantum transport, the electrical performance of PdCoO2 toward interconnect applications is evaluated. A nearly thickness independent room temperature resistivity is observed for flakes down to 40 nm thickness. The nanomembranes exhibit a breakdown current density up to 113 MA cm-2, with excellent thermal stability and electromigration resistance. These results demonstrate that mechanically exfoliated PdCoO2 flakes preserve the high crystalline and electronic quality of bulk
crystals in the quasi-2D limit, providing a useful platform for mesoscopic transport studies and interconnect applications.
Read the full abstract ▾
All authors Chengyu Zhu, Pahuni Jain, Yi Zhang, Junghyun Koo, Weideng Sun, Yaotian Li, Alexander McLeod, Chris Leighton, Gang Qiu
Plasma Physics
Interfacial transport driven by electrohydrodynamic instability at the plasma-liquid interface
Seungjun Lee, Woojin Nam and Gunsu Yun
Interfacial dynamics play a central role in transport processes across the
plasma-
liquid interface. While the strong electric field in the
plasma sheath can destabilize the
liquid surface and induce species transfer from the
liquid into the
plasma, the mechanistic relationship between surface instability and interfacial transport remains poorly understood. Here, we investigate the transport of sodium species in an atmospheric-pressure helium
plasma in contact with a negatively DC-biased NaCl electrolyte using high-speed imaging,
laser Mie scattering, and optical emission spectroscopy. The results show that Na transport is mediated by droplet emission from the
liquid surface and proceeds through three sequential stages: surface deformation, Taylor cone formation, and electrospray. The threshold voltage required for Na I optical emission decreases with decreasing surface tension, in good agreement with the marginal condition for electrohydrodynamic (EHD) instability predicted by linear perturbation analysis. These findings demonstrate that EHD-driven droplet emission is the primary mechanism carrying sodium ions from the
liquid into the
plasma, where they are neutralized and excited. More broadly, this work establishes surface instability as the active transport channel governing the injection of dissolved species from the
liquid into the
plasma, creating a unique reaction network of
plasma chemistry.
Read the full abstract ▾
Optics
Multifunctional Imaging with an Inverse-Designed Nonlocal Metasurface
Lincoln Clark, Yang Xu, Cat-Uyen Phan et al. (+6 more)
Nonlocal metasurfaces enable all-optical processing of spatial information in optical fields. Here, we demonstrate a
topology-optimised metasurface that switches between phase-contrast and brightfield imaging modalities via polarisation control, eliminating the need to reposition optical components or use computational techniques to image transparent samples. Specifically, for one polarisation state, an asymmetric transfer function about normal incidence performs a first order derivative on the phase, producing pseudo-3D phase-contrast images of transparent biological samples while the orthogonal state returns the result of the identity operator. This work extends inverse-design methods to reconfigurable phase-contrast microscopy and quantitative analogue optical computation with applications in biological imaging, medical diagnostics, and materials characterisation.
Read the full abstract ▾
All authors Lincoln Clark, Yang Xu, Cat-Uyen Phan, David J. Byrne, Shikun Ma, Lukas Wesemann, Elizabeth Hinde, Kylie L. Gorringe, Ann Roberts
Fluid Dynamics
On the large-scale vertical velocity intermittency of turbulent wall flows
Tirtha Banerjee, Elia Buono, Costantino Manes et al. (+6 more)
Large-scale intermittency in the vertical velocity (LSI) has received significant
attention in studies of coherent structures and their detection using data-driven approaches. However, a theory that predicts the origin of LSI from the Navier-Stokes equations or some approximated version of them at very high Reynolds numbers is yet to be achieved. This letter proposes such a theory for a neutrally stratified wall-bounded turbulent flow based on a dominant balance between inertial and pressure forces. Using multiple flume and wind tunnel experiments, it is shown that the flatness factor ($FF_w$) measuring LSI collapses to a universal trend for all flow configurations within the inertial sublayer (ISL) before reaching a common minimum value above the ISL. A theory that predicts $FF_w$ using second-order statistics and explicitly accommodates large-scale energy anisotropy is tested against a wide range of Reynolds numbers from laboratory to field settings with varied surface roughness conditions. The theory also demonstrates why $FF_w$ cannot be described using down-gradient closure approximations routinely employed in large-scale meteorological and
climate models.
Read the full abstract ▾
All authors Tirtha Banerjee, Elia Buono, Costantino Manes, Michael Heisel, Davide Poggi, Cosimo Peruzzi, Einara Zahn, Elie Bou-Zeid, Gabriel Katul
Instrumentation and Methods for Astrophysics
Quality Assessment of Spectroscopic Data Reduction Pipelines Using Artificial Intelligence: Scrutinizing Data Release 2 from the DESI Survey
V. Torres-Gomez, J. Suarez-Perez, J. E. Forero-Romero et al. (+45 more)
Large spectroscopic surveys now collect data at a scale that makes traditional visual inspection impractical. We present an unsupervised pipeline for spectroscopic quality assessment that requires no labeled training data. The method combines Uniform
Manifold Approximation and Projection for dimensionality reduction with Friends-of-Friends clustering to isolate anomalous spectra for targeted review. We apply this pipeline to 58,291,334 spectra across 14,199 tiles from DESI Data Release 2, processing each tile independently to produce a tile-level outlier catalog. In each tile, the pipeline separates a dense core of typical spectra from small, isolated components and singletons, yielding a total of 1,095,816 outlier candidates. The mean tile-level outlier fraction is about 1.96 percent overall, with values of 0.76 percent and 2.36 percent for the dark and bright main-survey programs, respectively. From the visual inspection of 391 outlier candidates from the dark and bright programs of the main survey, we find that 66.8 percent exhibit identifiable spectral anomalies consistent with known reduction and calibration effects. By contrast, only 4.1 percent carry a non-zero quality flag from the standard reduction pipeline. This shows that the method provides a complementary quality-assessment layer to existing pipeline diagnostics and recovers a substantial population of problematic spectra that standard diagnostics miss. Extrapolating to the main-survey catalog, we estimate that approximately 218,000 candidate outliers are free of identifiable reduction artifacts and may correspond to genuine atypical spectra in the context of DESI. The pipeline is scalable, reproducible, and directly comparable across successive data releases, making it a practical quality-assurance monitor for DESI and future multi-object spectroscopic surveys.
Read the full abstract ▾
All authors V. Torres-Gomez, J. Suarez-Perez, J. E. Forero-Romero, S. Bailey, A. Kremin, B. Dey, R. P. Nathan, S. Panda, J. Aguilar, S. Ahlen, D. Bianchi, D. Brooks, T. Claybaugh, A. de la Macorra, P. Doel, S. Ferraro, A. Font-Ribera, E. Gaztanaga, S. Gontcho A Gontcho, G. Gutierrez, K. Honscheid, C. Howlett, R. Joyce, S. Juneau, D. Kirkby, O. Lahav, M. Landriau, L. Le Guillou, M. E. Levi, M. Manera, A. Meisner, R. Miquel, J. Moustakas, S. Nadathur, N. Palanque-Delabrouille, W. J. Percival, F. Prada, I. Perez-Rafols, G. Rossi, L. Samushia, E. Sanchez, D. Schlegel, H. Seo, R. Sharples, J. Silber, G. Tarle, B. A. Weaver, H. Zou
Materials Science
M. Winter, A. Pignedoli, A. S. Sukhanov et al. (+18 more)
In most helimagnets, an applied
magnetic field aligns the propagation direction of a helical
spin texture with the field, resulting in a conical state and obscuring the unwinding process. Here, we access a complementary regime in the anisotropic
chiral magnet Mn$_{1.4}$PtSn, where
crystal symmetry constrains the propagation direction of the
spin modulation. Using resonant elastic X-ray scattering in a vector magnet, we track the
evolution of quasi-one-dimensional
spin textures that propagate along a
chiral crystallographic axis while the
magnetic field is applied perpendicular to this direction. Together with micromagnetic simulations, our measurements reveal a transformation from the zero-field $\pi$-
chiral soliton lattice into a fan-like state. In this state, the propagation direction remains transverse to the applied field, while the
spins oscillate about the field direction. During magnetization, the modulation length decreases continuously with the field and approaches the field-polarized state. Simulations indicate that magnetostatic interactions in finite samples play a key role in stabilizing this behavior. Our results provide evidence for a fan-like regime in a
chiral magnet and highlight how field orientation can be used to control one-dimensional
spin textures.
Read the full abstract ▾
All authors M. Winter, A. Pignedoli, A. S. Sukhanov, M. Azhar, A. Tahn, B. Achinuq, J. R. Bollard, V. Ukleev, C. Luo, F. Radu, S. Wintz, M. Weigand, A. Mistonov, P. Vir, J. Geck, C. Felser, G. van der Laan, T. Hesjedal, K. Everschor-Sitte, B. Rellinghaus, M. C. Rahn
Nuclear Theory
Ab Initio Nuclear Theory for Heavy Nuclei and Its Application to Dark Matter-Nucleus Scattering
Bai-Shan Hu
The era of precision ab initio
nuclear theory has arrived, enabling uncertainty-quantified predictions for
nuclear structure and for interactions with external probes directly from the underlying
nuclear force and electroweak currents. This review highlights recent breakthroughs that extend ab initio calculations to the heavy
nucleus $^{208}$Pb, to medium-mass systems with complex deformation, and to weakly-bound
nuclei near the driplines. We also summarize ab initio calculations of
nuclear responses for dark matter direct detection. Together, these advances demonstrate how ab initio methods can substantially reduce
nuclear-physics uncertainties in searches for physics beyond the Standard Model, providing a more robust interpretation of current and forthcoming precision experiments.
Read the full abstract ▾
General Relativity and Quantum Cosmology
Rational Orbits and Gravitational Waves in Static Spherical Spacetimes: An Open-Source Numerical Framework
Dan Li, Shiyang Hu, Chen Deng et al. (+2 more)
Timelike orbits constitute a crucial probe for exploring the intrinsic properties of curved spacetimes, and the carried gravitational radiation signals provide a direct window into strong field
gravity. In this paper, we develop a versatile computational framework based on Mathematica and the OpenMP parallel architecture to simulate the rational orbits of timelike particles and their gravitational radiation in static spherically symmetric spacetimes. Specifically, requiring only the user defined covariant metric, this numerical tool can efficiently calculate rational orbits across various configurations, as well as the corresponding gravitational wave polarization states and characteristic strains. The package presented here offers a highly efficient and comprehensive one-stop solution for investigating the properties of curved spacetimes and their potential observational signatures. To demonstrate the reliability and capability of our code, we apply it to the Schwarzschild spacetime as a test case, illustrating the functionality of the code across several key aspects, including the effective potential, stable orbital regions, rational and irrational orbits, and gravitational wave signals. Furthermore, we show that the gravitational waves emitted by an extreme-mass-ratio inspiral system composed of an intermediate mass black hole and the
Galactic Center supermassive black hole have the potential to be identified by future space detectors.
Read the full abstract ▾
All authors Dan Li, Shiyang Hu, Chen Deng, Shijie Tan, Guansheng He
General Relativity and Quantum Cosmology
Probing the Circular Unruh Effect with Cavity-Controlled Lamb Shifts
Yan Peng, Jiawei Hu and Hongwei Yu
The Unruh effect predicts that accelerated observers perceive the inertial
vacuum as populated by particles, providing a flat-spacetime analogue of Hawking radiation. Its direct observation, however, remains experimentally challenging, since an Unruh temperature of $1\,\mathrm{K}$ requires accelerations of order $10^{20}\,\mathrm{m/s^2}$. Here, we show that the Lamb shift of a centripetally accelerated atom inside a high-$Q$ cavity provides a sensitive spectroscopic probe of the Unruh effect at dramatically lower accelerations. The cavity reshapes the electromagnetic density of states and converts otherwise tiny noninertial corrections into tunable level shifts. Depending on the atomic angular velocity and cavity detuning, the Lamb shift can be enhanced, strongly quenched, or completely screened. Remarkably, for experimentally realistic parameters, a rotation-induced shift of order $10\;\mathrm{Hz}$ can arise already at accelerations as low as $0.5\,\mathrm{m/s^2}$, more than twenty orders of magnitude below the acceleration scale conventionally associated with direct Unruh detection. These results identify cavity-controlled Lamb-shift spectroscopy as a viable route toward laboratory tests of the circular Unruh effect in the ultralow-acceleration regime.
Read the full abstract ▾
Instrumentation and Methods for Astrophysics
Classification of Eclipsing Binary Light Curves in Gaia DR3: A Machine Learning Approach
Bedri Keskin and Özgür Baştürk
Gaia Data Release 3 (DR3) presents a unique
dataset with approximately 2.1 million eclipsing binary
star candidates. The unsustainability of manually classifying such a large volume of data has necessitated the development of reliable and scalable automated techniques. In this study, a novel
multimodal deep learning model has been developed for the automated classification of approximately 2 million eclipsing binary
stars in the
Gaia DR3 archive based on their light curve morphologies (EA, EB, EW). The developed architecture simultaneously utilizes a Convolutional Neural Network (CNN) that extracts visual features from light curve images and a Multilayer Perceptron (MLP) that processes
geometric model parameters. Noise-free synthetic light curves were used during the training process to ensure the model focuses on
geometric shapes. Tests showed that the model achieved an accuracy rate of over 95% for all classes, exhibiting excellent separation performance, particularly in EA-type systems. As a result of the automated classification performed with the trained model, 40% of the
Gaia DR3 eclipsing binaries were classified as EA, 30% as EB, and 30% as EW. This study provides a highly accurate and transferable classification framework for future large-scale sky surveys.
Read the full abstract ▾
Astrophysics of Galaxies
Clumpy Disk, Interloper, or Merger? Nature of a Distant Galaxy Pair at 5 kpc Projected Separation
Hajar Aziz, Vivian U, Archana Aravindan et al. (+8 more)
We present the morphological, photometric, and spectroscopic properties of a z ~ 1
galaxy, "lil gal", serendipitously detected in JWST Mid Infrared Instrument (MIRI) images of nearby
galaxy VV 340. In the MIRI F560W and F770W images, we identify what appears to be a spiral
galaxy with a central bulge. However, in the F1500W image, a second peak appears ~0.7" northwest (NW) from the central bulge, calling into question the nature of this source as a clumpy disk, a high-
redshift interloper, or a
galaxy merger. Multi-band analyses of the three MIRI and four Hubble Space
Telescope (HST) images suggest a photometric
redshift of ~0.92. Spectroscopic analyses of data from the Keck Near-Infrared Echellette Spectrometer (NIRES) reveal two sets of [N II] and H-alpha emission lines corresponding to the two observed sources. A
redshift of z = 0.9248 is identified for the NW companion. Fainter emission lines are identified from the underlying
galaxy at z = 0.9225, suggesting a merging
galaxy pair at a projected separation of ~5 kpc. From the emission line ratios from Keck NIRES and Keck
Cosmic Web Imager (KCWI) spectra, we classify the system as hosting regions of active
star formation, likely attributed to merger-induced starburst activity. The results demonstrate the necessity of resolved, spectroscopic follow-up analyses of
galaxies found in deep JWST images to disentangle the role of
galaxy mergers from clumpy disk
galaxies at z ~ 1 to
cosmic noon and beyond.
Read the full abstract ▾
All authors Hajar Aziz, Vivian U, Archana Aravindan, Raymond P. Remigio, Gabriela Canalizo, Justin A. Kader, Marina Bianchin, Yiqing Song, Tianmu Gao, Jeff Rich, Rosalie McGurk
Mesoscale and Nanoscale Physics
Electrically Programmable Correlated Topology and Magnetism in a Moiré Trilayer
Christiano Wang Beach, Courtney Baier, Kaijie Yang et al. (+15 more)
Strong electron-electron interactions underlie a wide range of
quantum many-body phenomena, including magnetism, superconductivity, and charge fractionalization. A central goal is to achieve in situ control over
lattice geometry, bandwidth, and band
topology within a single platform. Here we realize such an electrically programmable
quantum many-body system in an alternating twisted trilayer MoTe$_2$, where an out-of-plane displacement field continuously modifies the layer polarization, effective
lattice, and
topology of the moiré bands. At zero displacement field, the system realizes a triangular
lattice hosting a correlated
insulator at one hole per moiré unit
cell ($\nu = -1$). Doping this state produces strongly asymmetric
magnetic responses: double-exchange-like ferromagnetism for $|\nu| > 1$, and signatures of
spin polarons and antiferromagnetism for $|\nu| < 1$. At large displacement field, interlayer hybridization reconstructs the electronic structure into a honeycomb
lattice with a flat Chern band, supporting integer and fractional Chern
insulators. Magneto-optical measurements further reveal the signatures of gap closure and Landau-level formation from a
spin-polarized
Fermi surface near the crossover between the two regimes. These results establish a unified, electrically tunable platform in which correlated magnetism and topological states emerge from a single controllable band structure.
Read the full abstract ▾
All authors Christiano Wang Beach, Courtney Baier, Kaijie Yang, Huiyuan Zheng, Yueyao Fan, Weijie Li, Shuai Yuan, Yifan Zhao, Yue Sun, Chaowei Hu, Takashi Taniguchi, Kenji Watanabe, Jiun-haw Chu, Liang Fu, Ting Cao, Satoshi Okamoto, Di Xiao, Xiaodong Xu
Chemical Physics
Generalized Mpemba effect in diffusion-controlled spin-dependent delayed fluorescence
Kazuhiko Seki
The Mpemba effect is commonly associated with anomalous thermal relaxation, in which a system prepared at a higher temperature reaches
equilibrium faster than one prepared at a lower temperature. In modern formulations, however, its defining feature is broader: a state initially farther from
equilibrium can relax faster than a closer one, or, equivalently, relaxation trajectories can cross. Here, we show that
magnetic-field-dependent delayed fluorescence in triplet-fusion systems realizes a generalized Mpemba effect driven by external control of
spin-selective kinetics. Using a
diffusion-controlled geminate-recombination extension of the Johnson–Merrifield model, we demonstrate that delayed-fluorescence trajectories obtained at different
magnetic fields cross when geminate fusion is effective. We further derive a compact kinetic criterion for such crossing in terms of the competition between intermediate-time decay rates and long-time power-law amplitudes. This criterion captures the interplay between effective fast and slow relaxation contributions. Within this kinetic framework, the final state is independent of the external control parameter and is defined as the fully relaxed state in which no separated triplet population remains. The generalized Mpemba effect therefore arises from the redistribution of transient relaxation pathways associated with geminate recombination, whereas bulk
diffusion-controlled processes contribute only to the final relaxation. These results link anomalous relaxation in
spin-dependent photokinetics to modern formulations of the generalized Mpemba effect and show how trajectory crossing can emerge in systems governed by
diffusion-controlled geminate recombination and non-Markovian kinetics.
Read the full abstract ▾
Chemical Physics
A Unified Generative Framework for Scalable Chemical Reaction Network Exploration
Zechang Sun, Chenxi Hu, Kailai Lin et al. (+6 more)
Chemical reaction networks (CRNs) are crucial for understanding reaction mechanisms and guiding chemical synthesis, yet the computational exploration remains limited by the combinatorial growth of chemical space, the reliability of reaction path screening, and the cost of evaluating thermodynamic and kinetic properties. Here, we present ByteCRN, an end-to-end framework for computational CRN exploration that combines chemically informed reaction enumeration with generative transition state modeling. A key component of our framework is a generative rectified flow architecture for both transition state generation and reaction validation, where it maps reactant-product pairs to candidate transition state structures and verifies connectivity by mapping back to reactants and products. This unified generative strategy replaces the most expensive steps of conventional computational workflows, namely iterative transition state search and intrinsic reaction coordinate validation, within a complete CRN construction pipeline. ByteCRN delivers a 10–100-fold acceleration over traditional workflows while maintaining high predictive fidelity for individual reactions. At the network scale, it effectively prunes $\sim$70-90% of the enumerated reactions, streamlining the exploration of complex reaction space. Its utility is illustrated through the discovery of novel pathways involving cyanoacetaldehyde and the successful modeling of the challenging $\gamma$-ketohydroperoxide network, demonstrating a practical, scalable approach to autonomous chemical exploration.
Read the full abstract ▾
All authors Zechang Sun, Chenxi Hu, Kailai Lin, Jin Li, Changsu Cao, Dingshun Lv, Ji Chen, Weiluo Ren, Hung Q. Pham
High Energy Physics (Phenomenology)
Pion structure from its light-front wave function
Khépani Raya, Zhen-Ni Xu, Zhao-Qian Yao et al. (+1 more)
Understanding the structural properties of the pion is essential for elucidating the mechanisms of mass generation within the Standard Model and their role in the emergence and properties of the hadronic matter. Light-front wave functions encode extensive information about the internal structure of these systems and provide the link to measurable quantities such as generalized parton distributions and transverse-momentum-dependent distributions. Guided by recent progress in continuum Schwinger methods, we derive well-founded and practical representations of these quantities, enabling the exploration of several facets of the pion structure, including distribution amplitudes and distribution functions, elastic and gravitational form factors, and the associated momentum and spatial distributions. The results presented here are consistent with expectations and can be tested at modern experimental facilities, including the new generation of electron-ion
colliders.
Read the full abstract ▾
All authors Khépani Raya, Zhen-Ni Xu, Zhao-Qian Yao, José Rodríguez-Quintero
Mesoscale and Nanoscale Physics
Observation and Control of Spontaneous Magnon Emission from Spin Ensembles in 2D Hexagonal Boron Nitride
Ling-Jie Zhou, Jayakrishnan M. P. Nair, Senlei Li et al. (+10 more)
Hybrid systems consisting of color centers and
magnetic materials provide an appealing solid-state platform for advancing the burgeoning
quantum technological revolution. Exploring novel coupling mechanisms between optically active
spin defects and
quantum degrees of freedom is directly relevant in this context. Here, we report observation and control of spontaneous
magnon emission from boron-vacancy centers in 2D hexagonal boron nitride (hBN) to a proximal ferrimagnet in the near-zero temperature limit. The spontaneous
magnon emission process is overshadowed by thermal
magnon effect as temperature increases, reflecting the crossover from a spontaneous-emission-dominated
magnon reservoir to a thermally occupied
spin bath where absorption and stimulated processes restore balance. By increasing the
spin defect density, we further present that spontaneous
magnon emission into a common
spin bath could help establish
magnon-mediated correlations in dense hBN
spin ensembles. Our results are quantitatively captured by theoretical modeling, bringing insights into understanding
qubit-
magnon coupling, correlated
spin dynamics, and many-body physics of color centers in the
quantum regime.
Read the full abstract ▾
All authors Ling-Jie Zhou, Jayakrishnan M. P. Nair, Senlei Li, Thomas Poirier, Yiran Zhao, Zelong Xiong, Sumedh Rathi, Jingcheng Zhou, Zhigang Jiang, Hailong Wang, James H. Edgar, Benedetta Flebus, Chunhui Rita Du