General Relativity and Quantum Cosmology
Extended Thermodynamics and Throttling Process of Charged AdS Black Holes in ModMax-dRGT Massive Gravity with Sharma-Mittal Entropy
Naba Jyoti Gogoi, Hassan Hassanabadi, Himasri Pinapothu et al. (+1 more)
We investigate the extended thermodynamics, including the Joule-Thomson expansion and $P-V$ criticality, of a four-dimensional charged anti-de Sitter (AdS) black hole within the combined framework of ModMax nonlinear electrodynamics and dRGT-like massive
gravity. Operating in the extended phase space and employing the generalised Sharma-Mittal
entropy to account for non-extensive statistical correlations, we derive exact analytical expressions for the modified Hawking temperature, specific heat, Joule-Thomson coefficient, and the equation of state. Our analysis of the throttling process reveals that the conformal nonlinearities of the ModMax field ($\gamma$) expand the physically accessible cooling domain by shifting the inversion transition to smaller horizon radii. While the Sharma-Mittal parameters ($\delta$, $R$) critically govern local thermodynamic stability and the inversion radius, the global inversion phase boundary remains fundamentally dictated by the massive graviton background. Furthermore, an analysis of the Gibbs free energy uncovers a van der Waals-like first-order phase transition characterized by a distinct swallow-tail structure. We observe a clear physical decoupling in the critical regime: ModMax nonlinearities modify the critical phase boundary by suppressing electromagnetic interactions, Sharma-Mittal parameters dictate the relative thermal stability of competing phases, and massive
gravity governs the overarching macroscopic phase landscape. These results highlight the sensitivity of thermodynamic phase phenomena as robust diagnostic tools for distinguishing nonlinear and non-extensive modifications to black hole physics.
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All authors Naba Jyoti Gogoi, Hassan Hassanabadi, Himasri Pinapothu, Dhruba Jyoti Gogoi
Instrumentation and Methods for Astrophysics
Fast Simultaneous Surveys with On-the-Fly Mapping
Suman Chatterjee, Sarvesh Mangla, Sourabh Paul et al. (+10 more)
The SKAO is a next-generation
radio telescope that will transform our understanding of the formation and
evolution of
radio galaxies,
quasars, transients, and other
cosmic sources. Surveys conducted on precursor
telescopes can inform us about the capabilities and challenges to be overcome in preparation for SKAO science. The MeerKAT Large Area Synoptic Survey (MeerKLASS), is a pathfinder large area survey to probe cosmology using the single-dish ${\rm H\hspace{0.5mm}}{\scriptsize {\rm I}}$~intensity mapping (IM). MeerKLASS provides an additional wide, high angular-resolution commensal survey by utilizing the “On-the-Fly” (OTF) imaging technique. The survey target is to cover 10,000 sq. degrees in the Southern sky avoiding the
Galactic plane, using the UHF-band (544-1088 MHz). The survey aims to achieve an r.m.s. of 25 $\mu$Jy/beam and $14''$ resolution. In this chapter we discuss the survey strategy, observational status, the development of the MeerKLASS OTF imaging pipeline and the science prospects of the data products. OTF imaging, which relies upon constant elevation fast scanning, comes with its own set of challenges, such as smearing. Here we detail how we have mitigated them and the current scientific impact. Significantly fast survey speed ($\sim 3.5$ sq. deg per min), commensality with ${\rm H\hspace{0.5mm}}{\scriptsize {\rm I}}$~IM survey, deep and large area continuum images make MeerKLASS OTF an economic survey technique. Lessons from this technique will be valuable for the upcoming SKA-Mid, where we expect a better resolution $(< 2'')$ and sensitivity $(\sim 7\mu {\rm Jy/beam})$ of the OTF images with the AA4 configuration. Furthermore, improvements in the correlator will result in negligible smearing effects in the imaging.
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All authors Suman Chatterjee, Sarvesh Mangla, Sourabh Paul, Keith Grainge, Matthias Hoeft, Tamera Kassie, Joseph J. Mohr, Yvette Perrott, Kristof Rozgonyi, Mario G. Santos, Oleg M. Smirnov, Cyril Tasse, Laura Wolz
Plasma Physics
Single-Shot Intensity-Correlation Diffractive X-ray Imaging of ICF Plasmas
Kenan Qu, Daniel Bhatti and Nathaniel J. Fisch
X-ray radiography of inertial confinement fusion
plasmas is currently limited to several-micron resolution by
geometric blur, diffraction, and
photon-throughput tradeoffs. We propose single-shot intensity-correlation diffractive imaging (IDI) as a lensless route to submicron
plasma turbulence measurements under low-self-emission conditions. Rather than relying on physical apertures, IDI reconstructs
plasma morphology by
Fourier transforming the spatial correlations of chaotic far-field speckles via the Hanbury Brown-Twiss effect. The
Fourier phase is retrieved by applying bispectral closure-phase constraints derived from third-order intensity correlations. We demonstrate this submicron capability in a numerical simulation using a $50~\mathrm{keV}$ x-ray probe scattered by a spiral
plasma structure.
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Instrumentation and Detectors
Application of surface coating for radon mitigation in rare-event searches
Florian Jörg, Guillaume Eurin and Hardy Simgen
Rare-event searches offer a powerful avenue for investigating some of the most fundamental questions in modern physics, most prominently the particle nature of dark matter and the possible Majorana nature of the
neutrino. Often, their dominant source of background comes from the radioactive noble gas radon emanating from materials. We report on a novel strategy to mitigate this background by the application of coating layers. A method for electroplating of copper was developed that showed a thousandfold reduction of the $^{222}$Rn emanation rate from a $^{226}$Ra-implanted stainless steel sample.
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Applied Physics · Cross-listed from cs.RO
Morphology-Specific Closed-Loop Control of Logarithmic-Spiral Continuum Arms via Online Jacobian Error Compensation
Partha Datta, Yi Jin, Wei Lin et al. (+1 more)
Logarithmic spirals are ubiquitous in biological appendages and provide an attractive morphology for continuum manipulators capable of reaching, wrapping, and grasping. Recently reported logarithmic-spiral
robots demonstrated scalable fabrication and versatile grasping but lacked inverse kinematics and closed-loop control. This work presents the first morphology-specific closed-loop task-space control framework for logarithmic-spiral continuum arms. A segmented tendon-driven model with a centerline backbone and equilateral tendon routing is developed in MuJoCo to capture tapered compliance and contact dynamics. An analytical task-space Jacobian is derived directly from the logarithmic-spiral kinematics and combined with online Jacobian error compensation using a Broyden secant update and Kalman-filter estimation. The resulting controller continuously corrects modeling errors arising from nonlinear deformation, contact, and
geometric mismatch. The framework is validated through planar and spatial simulations, including trajectory tracking, attitude regulation, disturbance rejection, three-dimensional position tracking, and simultaneous position-orientation control. Compared with a piecewise-constant-
curvature (PCC) baseline, the proposed method consistently reduces tracking errors, suppresses attitude drift, and maintains a bounded Jacobian estimation error. The controller is further applied to morphology-enabled manipulation tasks, including obstacle-assisted reach-wrap-release motions, adaptive whole-arm grasping, and cooperative multi-arm object handling. Results demonstrate that combining logarithmic-spiral morphology with online Jacobian compensation enables accurate, robust, and scalable control of highly underactuated continuum manipulators. The proposed framework establishes a physics-grounded baseline for future hardware implementation and learning-augmented soft robotic control.
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All authors Partha Datta, Yi Jin, Wei Lin, C. Chase Cao
Earth and Planetary Astrophysics
Measuring Asteroid Rotation Periods Using the KMTNet Bulge Survey Data
Haitao Huang, Hongjing Yang, Chung-Uk Lee et al. (+6 more)
Since 2015, the Korea Microlensing
Telescope Network (KMTNet) has conducted high-cadence, near-continuous observations of the
Galactic bulge for nearly nine months each year from three sites in Chile, South Africa, and Australia, and its wide field of view provides a unique opportunity to extract asteroid lightcurves from archival survey data. In this work, we performed photometric measurements of bright asteroids ($V< 20$~mag) identified within a one-square-degree field during the 2018 KMTNet bulge season. We derived reliable rotation periods for 96 asteroids, including 84 objects without previously published lightcurves. The reliable
spin-rates of the asteroids in our sample are broadly consistent with those reported in the Asteroid Lightcurve Database. This archival mining approach can be readily extended to a much larger KMTNet footprint, and the existing $\sim12$~deg$^2$ high-cadence KMTNet
dataset has the potential to yield reliable rotation periods (U $\geq 2+$) for more than 5,500 asteroids, substantially expanding the current database of asteroid rotational properties.
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All authors Haitao Huang, Hongjing Yang, Chung-Uk Lee, Qiyue Qian, Jun Tian, Tianjun Gan, Shude Mao, Weicheng Zang, Dong-Jin Kim
General Relativity and Quantum Cosmology
Gravitational Wave Signatures from Periodic Orbits around a Non–commutative Schwarzschild Black Hole
N. Heidari, A. A. Araújo Filho, I. P. Lobo et al. (+1 more)
In this work, we investigate massive particle motion and the gravitational wave emission generated by periodic trajectories around a non–commutative Schwarzschild black hole sourced by a Lorentzian matter distribution. We analyze the effective potential, the marginally bound orbit, and the innermost stable circular orbit, showing that non–commutative corrections shift these characteristic orbits toward smaller radii and reduce their corresponding angular momenta. The allowed region in the $(E, L)$ plane is also displaced toward lower values, favoring more tightly bound configurations. Periodic trajectories are classified through the rational parameter $q$, which relates the radial and azimuthal frequencies. For a fixed orbital
topology, increasing the non–commutative parameter lowers the energy required to produce the orbit and results in more compact zoom–whirl configurations. Small deviations from the periodic energies are also shown to generate precessional drift. From the periastron advance of the S2
star around Sgr~A$^*$, we obtain the preliminary bound $\Theta/M^{2}<0.014$. Finally, using the adiabatic and numerical kludge approximations, we compute the gravitational wave polarizations and find phase shifts and an overall enhancement of the amplitude.
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All authors N. Heidari, A. A. Araújo Filho, I. P. Lobo, V. B. Bezerra
Atomic Physics
Infinite-time surface flux for full-dimensional three-body breakup dynamics
Jinzhen Zhu
We derive an infinite-time surface-flux formulation for full-dimensional three-body breakup dynamics in intense
laser fields. The method is designed as a post-pulse extension of time-dependent surface flux (tSurff) calculations for systems with two asymptotic fragments, with helium double ionization and dissociative ionization of $\hydroplus$ as representative applications. Standard tSurff calculations avoid projection on very large boxes, but the spectra still contain a field-free tail after the
laser pulse; converging this tail by direct propagation can be expensive for slow particles, narrow resonances, and long-range Coulomb channels. Here the post-pulse time integrals are rewritten as resolvents of the field-free one-particle ionic
Hamiltonians and of the full field-free three-body
Hamiltonian. The resulting expressions separate the already available tSurff amplitudes from stationary correction terms that can be evaluated from saved wave functions in the inner and single-ionization regions. The formulation gives a common theoretical structure for electron-electron breakup in helium and electron-
nuclear breakup in $\hydroplus$, and it is compatible with the spectral decompositions and MPI-parallel workflow of the tRecX framework. This provides a practical route to tSurff+iSurff calculations of correlated three-body spectra without long post-pulse propagation and without solving a large complex linear system independently for every final momentum.
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General Relativity and Quantum Cosmology
Electrically Charged Distorted Black Holes: Thermodynamics, Particle Dynamics, and Quasinormal Signatures
Gamal G.L. Nashed and Salvatore Capozziello
We construct an exact solution for the electrically charged extension of a distorted black hole spacetime within Einstein-Maxwell theory using the Harrison transformation. The resulting solution represents a charged deformation of a static distorted
vacuum geometry in which the electromagnetic field is introduced through a nonlinear transformation preserving the radial structure of the seed spacetime. Consequently, the Killing horizon remains determined solely by the seed metric and it is not shifted by the electric charge. We analyze the thermodynamic properties of the solution and show that the horizon area,
entropy, and temperature are governed by the
geometric sector, while the electric charge enlarges the thermodynamic phase space through the electromagnetic potential. The motion of charged test particles is studied using the effective potential formalism, where the distortion parameter modifies circular orbits and shifts the location of the innermost stable circular orbit. We also investigate the black hole shadow for a static observer at finite distance and show that the distortion parameter displaces the
photon sphere outward, increasing the apparent shadow size. A
geometric correspondence between the
photon orbit, determining the shadow and the leading eikonal quasinormal-mode frequency, is discussed, linking optical and perturbative observables. Finally, we study charged scalar perturbations and show that the vanishing horizon electric potential prevents a charged superradiant amplification. In the weak-coupling regime, the quasinormal-mode spectrum is estimated using the WKB method, where the electromagnetic interaction enters through the gauge-invariant combination $(\omega - q_s \xi_t)$ and shifts the oscillation frequencies of the perturbations.
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Chaotic Dynamics
Internal Reliability of Coupled Kuramoto-Sakaguchi Phase Oscillators
Arkady Pikovsky, Franco Bagnoli and Stefano Iubini
The notion of internal reliability in dynamical networks describes whether replicas of a particular unit follow the dynamics of the reference unit. Reliability and anti-reliability can be quantified by the transversal Lyapunov exponents. We study phase oscillators coupled via Kuramoto-Sakaguchi-type interactions. Already the simplest solvable system of two oscillators demonstrates nontrivial reliability properties. We present numerical evidence of reliability and anti-reliability in small networks with a uniform distribution of natural frequencies. The dynamics of an ensemble of replicas can be described within the Watanabe-Strogatz theory, which predicts
symmetry of the transversal Lyapunov exponents for replica-attractor and replica-repeller.
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Quantum Physics
Criterion for qubit-assisted quantum metrology approaching Heisenberg scaling
Peng Chen and Jun Jing
We study in this work the metrology precision of a probe system coupled to an ancillary
qubit. Restricting the probe-
qubit coupling along only one or two directions is found to be a sufficient criterion for the effective dynamical generator to achieve the Heisenberg limit in precision. Under the criterion, the
quantum Fisher information (QFI) about the to-be-estimated parameter becomes the expectation value of mean square of the effective generator with respect to the initial state of the composite system. Our criterion is justified in two distinct systems. For a bosonic probe, QFI about the displacement estimation is found to be proportional to the mean excitation number of probe. It renders a counterintuitive result that
quantum metrology sensitivity can be enhanced by increasing the temperature of the probe system. For a
spin-ensemble probe, QFI about both rotation-phase and
magnetic-field estimation exhibit a quadratic dependence on the probe-
spin number. It is found that even when the
spin-ensemble is prepared as a finite-temperature state, faraway from the so-called resource states, e.g., the squeezed state or the Greenberger-Horne-Zeilinger state, QFI can still manifest a Heisenberg scaling behavior.
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General Relativity and Quantum Cosmology
Images of Braneworld black holes with radiatively inefficient accretion flows
Chengjia Chen, Yin Hao, Zelin Zhang et al. (+2 more)
Horizon-scale imaging acts as a transformative tool for probing spacetime geometry, enabling stringent tests of gravitational theories in the strong-field regime. The Casadio-Fabbri-Mazzacurati(CFM) black hole in braneworld contains an extra parameter that characterizes the
tidal effects from the bulk geometry, making it highly valuable for this task. We perform general relativistic radiative transfer (GRRT) simulations and generate synthetic images consistent with Event Horizon
Telescope observations of M87*. We find that the
tidal parameter imprints nonmonotonic changes on the image morphology, underscoring the intricate coupling between spacetime geometry and the observable radiation from the accreting
plasma. We also analyze the image-comparison metric using normalized cross-correlation coefficients and the DSSIM index and find that the magnitudes of these mismatches are on the order of 10^3, which implies that identifying braneworld black holes through black hole images remains challenging even with future ngEHT and BHEX observations.
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All authors Chengjia Chen, Yin Hao, Zelin Zhang, Qiyuan Pan, Jiliang Jing
Data Analysis and Statistics · Cross-listed from cs.LG
\chisao{}: A GPU-Native Parallel Optimizer for Multimodal Black-Box Functions via Convergence-Anticonvergence Oscillation
Ira Wolfson
Finding all modes of a
multimodal black-box function is a fundamental challenge in optimization,
Bayesian inference, and scientific computing. Existing approaches – basin-hopping, CMA-ES, multistart gradient descent – operate sequentially and cannot exploit the massive parallelism of modern GPU hardware. We introduce \chisao{} (Convergence-Halt-Invert-Stick-And-Oscillate), a GPU-native population optimizer that runs an entire sample batch simultaneously and exploits a deliberate convergence-anticonvergence oscillation cycle to escape local traps while freezing confirmed modes. The structural move is asymmetric: samples that reach true peaks are frozen (“stuck”) and preserved, while the rest keep exploring via momentum-based anti-convergence and stochastically smoothed gradients. Adaptive reseeding via two complementary strategies (Repulse Monkey and Golden Rooster) maintains population diversity throughout. On all 42 functions of the Simon Fraser University optimization
benchmark suite across dimensions $d \in \{2, 4, 8, 16, 32, 64\}$, \chisao{} achieves 100% mode recovery where all CPU baselines collapse at $d \geq 8$ on the hardest
multimodal functions, at up to \textbf{$34\times$} speedup over basin-hopping on functions where all methods succeed (Michalewicz $d=64$) and up to \textbf{$39\times$} on unimodal functions (Rotated Hyper-Ellipsoid $d=64$, pure GPU dividend). All
benchmarks evaluate the objective by value alone – gradients come from finite differences – so the reported speedups are a derivative-free worst case. Under substantial likelihood noise ($\sigma_{\mathrm{noise}}$ up to 1.0), mode detection remains 100% reliable. The
algorithm is available as a standalone open-source Python package on PyPI.
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High Energy Physics (Theory)
Large-$N$ Carrollian Thermodynamics from AdS Black-Hole Phase-Space Contractions
Yingnan Xu and Shuangshuang Chu
We develop the boundary large-rank interpretation of finite Carrollian black-hole thermodynamics and its sourced stress, scalar spectral and interacting thermal observables. Correlated scaling of the time generator and Newton coupling preserves the extended
Hamiltonian differential while the generator temperature vanishes and the
holographic normalization grows. The Brown–York source variation fixes the relative weights of energy density, momentum density and spatial stress, giving Ward equations on the Carrollian and thermal time scales. Boundary volume and normalization variations reproduce the bulk pressure work and characterize the Hawking–Page crossing through a chemical potential. Source coupling fixes the scalar operator map and spectral clock Jacobian. Numerical solutions in four-dimensional Schwarzschild-AdS determine angular transmission and finite-frequency absorption. In the type IIB family, the logarithmic scrambling interval imposes an additional hierarchy between rank and 't Hooft coupling. We derive a correlated limit in which the string length vanishes while a finite transverse Regge kernel survives in the normalized four-point functional. Its integrated attenuation and spatial width obey a common relation. This interacting observable distinguishes large-rank sequences with the same leading thermodynamics and asymptotic Regge growth rate. Thermal
Fourier–Mellin moments retain the scalar spectrum in a contracting frequency window. Time translations shift their weights with angular source terms retained. The BTZ dictionary supplies the corresponding large-central-charge
equilibrium example.
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Quantum Physics
Dissipative Quantum Multiplicative Weights with Sampling Feedback: A Classically Hard Primitive Realized via Engineered Open-System Dynamics
Agung Trisetyarso, Lenny Putri Yulianti and Kridanto Surendro
We introduce Dissipative
Quantum Multiplicative Weights with Sampling Feedback (DQMW-Sample), an online-learning primitive in which engineered open
quantum-system dynamics prepare a Gibbs state whose computational-basis measurement supplies the loss feedback. The central conceptual contribution is to lift the computational hardness of constant-temperature Gibbs sampling into a physically realizable online-learning primitive. By engineering a Davies-type dissipator whose per-round feedback cannot be efficiently simulated classically, we obtain a learning-theoretic separation in which DQMW-Sample achieves asymptotically sublinear regret while every efficient classical learner suffers constant average regret on a suitably constructed instance. We further prove that the spectral gap of the engineered dissipator contracts hardware noise, yielding sublinear noise-induced regret under a balanced dissipation schedule, and we strengthen the single-round hardness to the full adaptive interaction: an efficient classical simulator of the entire $T$-round feedback process would collapse the
polynomial hierarchy. We state the required realizability assumption in explicit form and report an initial hardware characterization on the IBM Heron~r2 processor. These results position DQMW-Sample as a concrete route toward computational advantage in online learning that is grounded in complexity theory and compatible with near-term superconducting hardware.
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General Relativity and Quantum Cosmology
Charged Axially Symmetric Exponential Metric: Exact Solutions to the Einstein-Maxwell Equations
S. Habib Mazharimousavi
We construct and analyze charged and magnetized extensions of the axially symmetric exponential metric, that is known as the Curzon-Chazy spacetime (CCS) within the Weyl class. Working within the Einstein-Maxwell framework, we first derive an exact charged axially symmetric exponential metric by directly solving the coupled field equations for a dyonic monopole configuration. The solution is shown to reduce smoothly to the
vacuum CCS in the neutral limit and to the extremal Reissner-Nordström spacetime in a special parameter regime. We then rederive the same charged geometry using the Harrison transformation in the Ernst formalism, establishing the equivalence between the direct and solution-generating approaches. Subsequently, we apply the
magnetic Harrison transformation to obtain a Melvin-type magnetized deformation of the spacetime. Finally, by implementing the Ehlers transformation, we generate a stationary but nonrotating swirling geometry endowed with a nonvanishing NUT charge, which we identify invariantly via the Komar dual mass. A further
magnetic Harrison transformation yields a magnetized swirling (NUT-type) spacetime. These results demonstrate how electric,
magnetic, and gravitomagnetic charges arise systematically from the CCS through exact solution-generating techniques.
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Optics
Microparticles manipulation with a three-dimensional closed optical trap
Chunyu Zhang, Xinran Fang, Pengcheng Mao et al. (+1 more)
Gaussian optical tweezers have strong phototoxicity to bioactive substances and it is difficult to achieve capture and manipulation of multiple particles. Moreover,
vortex optical tweezers face several challenges, such as weak axial confinement and dependence on complex optical elements like a spatial light modulator (SLM). Therefore, we design and construct a novel three-dimensional (3D) "optical spindle trap" (OST) system that does not require a SLM. By employing intracavity mode modulation and a simple extra-cavity lens modulation, we generate a fully enclosed 3D dark potential well with zero central intensity. Experimental results demonstrate that the system achieves stable trapping of single or multiple micrometer-sized particles with excellent 3D confinement and enables the trapping of mouse hepatocytes under low-power conditions. The system exhibits high physical stability. Its closed dark-field structure can also reduce phototoxic damage to biological samples. Furthermore, the dimensions of the optical trap can be flexibly tuned to suit various application scenarios. This study provides a novel, highly efficient, gentle, and low-cost optical trap platform for biomedicine and micro/nanoscale manipulation.
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All authors Chunyu Zhang, Xinran Fang, Pengcheng Mao, Dongxu Zhao
Astrophysics of Galaxies
A Population of Little Red Dot-like Quasars in SDSS
Quinn O. Casey, Ryan C. Hickox, Nikko J. Cleri et al. (+6 more)
Compact and red sources in the high
redshift ($z\sim5$) Universe, known as "Little Red Dots" (LRDs), are among JWST's most intriguing discoveries. These sources have broad Balmer emission lines, weak X-ray emission, and unique spectral energy distributions (SEDs) poorly fit by either
stellar or AGN templates. Local LRD-like objects allow for detailed studies of the underlying physical processes with archival multi-wavelength
datasets unavailable in the high-$z$ Universe. We show that the SDSS $ugriz$ filters at $z\approx0.4, 0.8$ overlap well with the JWST filters used to select LRDs at $z\sim5$. We use SDSS
quasars to define a sample of $\sim1300$ Local Red Dots (LoRDs) which share the same photometric colors of LRDs. A subset of the LoRD sample selected to have V-shaped continua ($N=244$) show prominent higher-order Balmer absorption features and [NeV]$\lambda$3426 emission, both of which would likely be missed in JWST/PRISM observations given the low spectral resolution. A composite SED of the LoRDs differs from a typical
quasar SED in the rest-frame UV/optical, but the two agree with each other in the NIR. The LoRD SED matches well with a stack of LRDs and can be modeled either as a reddened AGN combined with a host
galaxy, or as a reddened AGN combined with a host
galaxy and a cool blackbody. Interestingly, the LoRDs are X-ray detected at a rate comparable to typical
quasars. However, the probability that LoRDs and typical
quasars would go undetected, if subject to the LRD X-ray upper limits, is $>50\%$.
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All authors Quinn O. Casey, Ryan C. Hickox, Nikko J. Cleri, Jonathan H. Cohn, David M. Alexander, Emmanuel Durodola, Kelly E. Whalen, Raphael E. Hviding, Tonima Tasnim Ananna
High Energy Physics (Phenomenology)
Positron-Emitting and Electron-Capturing Double-Beta Processes in the Standard Model and Beyond
Lukáš Gráf, Jenni Kotila and Oliver Scholer
We study positron-emitting and electron-capturing double-beta-decay modes as probes complementary to the usual double beta decay. Motivated by the proposed NuDoubt++ experiment, we analyze the candidate isotopes ${}^{78}$Kr, ${}^{106}$Cd, and ${}^{124}$Xe, providing
nuclear matrix elements and phase-space factors for both neutrinoful and neutrinoless modes. For the Standard-Model channels, we find that $2\nu$ECEC and $2\nu\beta^+$EC are the most experimentally accessible, whereas $2\nu\beta^+\beta^+$ remains strongly phase-space suppressed. For the neutrinoless channel, we interpret a projected sensitivity of $T_{1/2}^{0\nu} = 10^{24}$ y in terms of dimension-seven SMEFT operators and find sensitivity to
lepton-number-violating new-physics scales of order 1-100 TeV. We further show that measurements in multiple isotopes can help to resolve degeneracies in multi-operator scenarios, making positron-emitting double-beta searches a useful complement to conventional neutrinoless double beta decay experiments.
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Strongly Correlated Electrons
Higher Berry curvature, second Chern numbers and magnetoelectric coupling in crystalline insulators
Niclas Heinsdorf and Ken Shiozaki
We rewrite a
lattice model of the four-dimensional Chern
insulator as a family of translationally-invariant infinite chains over the three-dimensional Brillouin zone and compute its higher three-form Berry
curvature using infinite
matrix product states (iMPS). We calculate the topological phase diagram of the associated Dixmier–Douady–Kapustin–Spodyneiko (DDKS) number as a function of the model's mass term, and show that it is exactly congruent to the phase diagram in terms of the second Chern number, the analytic expression of which is known for this particular model. This agreement demonstrates that higher Berry
curvature can be used to compute second Chern numbers in a manifestly quantized manner. Motivated by the connection between the second Chern form and the Chern–Simons
axion coupling, we study magnetoelectric coupling in three dimensions and its relation to higher Berry phases.
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Quantum Physics
Fast mixing of all-to-all quantum systems at high temperatures
Thiago Bergamaschi
It is shown that arbitrary
quantum $k$-local
Hamiltonians with bounded strength interactions admit a
quantum Gibbs sampler [CKG23] with a system-size independent spectral gap, at sufficiently high temperatures. As a consequence, such systems admit fully-
polynomial time
quantum approximation
algorithms for partition functions and global expectation values.
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High Energy Physics (Experiment)
Parnassus: A GPU-enabled, Python-based Package for Fast Particle Detector Simulation and Reconstruction
Abdelrahman Elabd, Eilam Gross, Dmitrii Kobylianskii et al. (+1 more)
We present the public software release of Parnassus, a Python/PyTorch, GPU-compatible framework for fast detector simulation and reconstruction in particle and
nuclear physics. Parnassus provides a user-friendly framework with interchangeable detector models: neural models can emulate computationally expensive Geant4-based detector simulation and reconstruction chains, while parametric models provide PyTorch implementations of selected Delphes-style detector responses. This initial release includes two models of the CMS detector: one based on a flow-matching neural network architecture and one based on a PyTorch implementation of the Delphes CMS card (parametric bias and smearing). PyTorch versions of the ATLAS and ALEPH Delphes cards are also available, together with a flow-matching neural model of the ALEPH detector that extends the framework to the e+e- LEP environment. All detector-specific backends share the same process-agnostic and detector-agnostic API: users select a detector card - analogous to choosing a detector card in Delphes - and the same tool can be applied to new physics processes without retraining the released detector model. There are native interfaces to the event generator Pythia and the event clustering package FastJet. Unlike previous C++/ROOT-based tools, Parnassus provides GPU-capable PyTorch detector-response backends and requires no ROOT installation. We describe the installation, command-line and Python API, configuration system, and demonstrate the framework on Standard Model and BSM processes.
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All authors Abdelrahman Elabd, Eilam Gross, Dmitrii Kobylianskii, Benjamin Nachman
Quantum Physics
Simulating Universal Quantum Gate Sets on Photonic OAM Qubits: Single-Qubit and Multi-Qubit Operations via Spatial Light Modulator Phase Holography
Saleha Maqsood, Muhammad Kamran and Tahir Malik
Spatial light modulators (SLMs) have emerged as reconfigurable platforms for photonic
quantum information processing, offering software-defined control over the orbital angular momentum (OAM) of light encoded in Laguerre-Gaussian (LG) beams. This paper presents a comprehensive simulation and hardware-grounded fidelity analysis of
quantum gate operations implemented on the HOLOEYE LC 2012 transmissive SLM. A realistic three-channel noise model comprising 8-bit quantisation noise, twisted-nematic (TN) electronic and thermal noise, and phase-wrap clipping error is obtained from the manufacturer's datasheet without free-parameter fitting, yielding a total noise of $\sigma_{\text{total}} = 92.4\text{mrad}$. The complete universal single-
qubit gate set $\{X, Y, Z, S, T, H\}$ and two-
qubit entangling gates $\{\text{CNOT}, \text{CZ}, \text{SWAP}\}$ are simulated on a $512 \times 512$ computational grid. Results show that predicted gate fidelity are in the range of $F = 0.9914\text{--}0.9936$, with fork grating gates limited primarily by TN noise and phase gates achieving higher fidelity owing to zero phase-wrap clipping error. In addition, Bell state preparation via the H-CNOT
circuit achieves $F(\Phi^+) = 0.9914$ after two SLM interactions. We
benchmark our obtained results against six published experimental studies spanning the 78%–99.6% fidelity range. Finally, a wavelength-dependent analysis identifies 450–532 nm operation as the optimal regime for this device.
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Quantum Physics
Analytic Approach to Quantum Control Using Quantum Signal Processing
Aishwarya Majumdar, John M. Martyn, Yuan Liu et al. (+1 more)
Realizing coherent
quantum computation requires precise and robust manipulation of
quantum systems through
quantum control protocols. Most
quantum control techniques rely on heuristic methods for designing the driving pulses that steer the system towards a target state. Such methods are often based on brute-force optimization and offer limited understanding of the solution landscape. In contrast,
quantum algorithms offer a rich body of analytical methods with rigorous error guarantees for implementing
unitary and non-
unitary transformations, which suggests a promising direction for developing new approaches to
quantum control. Among various such
algorithms,
quantum signal processing (QSP) has emerged as a powerful framework for
quantum algorithm design, implementation, and optimization. However, its potential for
quantum control remains largely unexplored. In this work, we establish QSP-Control, an analytical framework for
quantum control of
qubit-oscillator dynamics. We focus on dispersively coupled
qubit-oscillator systems and employ the QSP formalism to mitigate unwanted nonlinear effects arising from cross-Kerr interactions. In addition, we develop constructions for precise manipulation of Fock states by designing Fock-state-selective operators, based on structural parallels between the Jaynes-Cummings interaction and QSP. These findings demonstrate how several practically relevant problems in
quantum control can be mapped to forms amenable to QSP, offering both a systematic design framework and an interpretable perspective on
quantum control.
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All authors Aishwarya Majumdar, John M. Martyn, Yuan Liu, Nathan Wiebe
Quantum Physics
Operational certification of nonclassicality in arbitrary quantum states from few copies
Sudip Chakrabarty, Bivas Mallick, Ananda G. Maity et al. (+1 more)
States with negative Wigner functions constitute a fundamental nonclassical resource underlying
quantum advantage. However, their experimental certification typically relies on reconstructing the full phase-space distribution, resulting in a prohibitive measurement overhead for arbitrary
quantum states. In this letter, we overcome this limitation by introducing Wigner moments, a family of global phase-space quantities that admit an exact multicopy realization as parity expectation values, and are therefore directly measurable from only a modest number of state copies. This operational correspondence enables systematic hierarchies of detection criteria together with experimentally accessible lower bounds on the logarithmic Wigner negativity, and constitutes a genuine measure of nonclassicality. Numerical benchmarking of our protocol reveals a substantial reduction in copy budget relative to conventional Wigner
tomography, establishing Wigner moments as an efficient framework for certifying continuous-variable
quantum resources such as genuine multipartite
entanglement.
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All authors Sudip Chakrabarty, Bivas Mallick, Ananda G. Maity, A. S. Majumdar
Strongly Correlated Electrons
Folds of one curve: the superradiant phase diagram of Dicke modes with interacting matter
Max Hörmann
We give a thermodynamic-limit account of Dicke models with one cavity mode coupled collectively to interacting matter. Integrating out the cavity yields an exact self-consistent functional of the magnetisation $m$, $\tilde e(m) = \lambda m^2/2 + e_{\rm mat}(\lambda m)$: a classical penalty on the bare-matter energy $e_{\rm mat}$ in the self-consistent field $h = \lambda m$, with $\lambda = g^2/(2\omega_c)$ the collective coupling. Supplying only that scalar field, the
photon creates no phase the matter does not already possess. States holding a minimum form one connected curve, $\lambda(m) = \mu_{\rm mat}^{-1}(m)/m$, so superradiant first-order transitions are folds of one equation of state not crossings of disjoint sheets, and a fold can straighten into a continuous line. The remaining rules are local, each with a spectral counterpart: onset by the leading singularity of $e_{\rm mat}$ (a softening polariton), order by one bare response – the Landau quartic, or a divergent susceptibility forcing a Larkin-Pikin (LP) fold. For the Dicke-Ising model the Landau coefficients are exact, giving in closed form the second-order boundary and both zero-quartic fields, one tricritical; a $1/d$ expansion maps all four phases, with the AS-PS transition first order for $d\le d_{uc}=3=4-z$ (LP) and tricritical points in the $(d,\epsilon)$ plane above. At the degenerate quadruple point the matter is a Rydberg-blockade chain, solved by strict-blockade iDMRG: the
antiferromagnetic superradiant (AS) phase persists as a finite 1D wedge, first order into the corner. Other magnets: the triangular antiferromagnet keeps a continuous superradiant-superradiant line (3D-XY, no fold forced); the compass chain a BKT-functional onset; the Heisenberg and XX chains, via a conserved operator, a spectrally silent first-order onset; and the Dicke-Heisenberg diagram an exact tricritical point at the saturation corner.
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Quantum Physics
Many-Body Second Order Green's Function Theory for Ab Initio Molecular Quantum Electrodynamics
Amirhosein Amini, Jaime Cerda, Leopoldo Mejía et al. (+1 more)
In this work, we develop two many-body
quantum electrodynamic methods to calculate the ground-state energies of strongly coupled light-matter molecular systems. Specifically, we extend the second-order many-body Green's function theory (GF2) for electronic systems to incorporate electron-
boson couplings. We employ two ansätze to treat the bosonic part of the system, namely the coherent-state (CS) and Lang-Firsov (LF) transformed
vacuum state. These are combined with the GF2 method to construct two new approaches, which we refer to as CS-GF2 and LF-GF2. We
benchmark CS- and LF-GF2 by studying various molecular systems inside an optical cavity. We investigate $\mathrm{H}_2$ and $\mathrm{LiH}$ potential energy surfaces, keto-enol tautomerization energy barrier, van der Waals interactions between two $\mathrm{H_2}$ molecules and the torsional potential energy surface of the ethylene molecule, $\mathrm{C_2H_4}$. Both methods provide similar energy profiles, with relatively small differences between CS-GF2 and LF-GF2. Comparisons with the reference calculations also reveal remaining limitations at stretched bond lengths and near the twisted ethylene configuration. We additionally
benchmark CS-GF2 against exact diagonalization for a two-site Hubbard-Holstein model and observe that it closely reproduces the coupling-induced energy change in the weakly interacting regime while improving upon CS-MP2 in the strongly interacting regime. Overall, the results demonstrate that CS-GF2 and LF-GF2 provide self-consistent descriptions of correlated molecular electron-
boson systems, offering a many-body Green's function alternative for studying ground-state cavity-modified systems.
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All authors Amirhosein Amini, Jaime Cerda, Leopoldo Mejía, Arkajit Mandal
Earth and Planetary Astrophysics
Glossy Silicate Clouds on the Scorched Dayside of LTT9779b
Suman Saha, James S. Jenkins, Jonathan Brande et al. (+10 more)
Discovered deep within the "Neptunian desert", LTT9779b remains the only known ultra-hot Neptune, prompting significant speculation regarding its unique formation and evolutionary history. Its exceptionally high
geometric albedo has previously been attributed either to the presence of clouds or to an extremely metal-rich atmosphere. Here, we present a comprehensive panchromatic analysis of its dayside atmosphere using JWST NIRISS and NIRSpec/G395H observations to characterize its atmospheric structure and composition. Leveraging the exceptional signal-to-noise ratio (S/N) in the observed spectra, we report a 3-to-5$\sigma$ detection of dayside clouds, with strong evidence for Mg$_2$SiO$_4$(s) (silicate) condensation. This constitutes the first statistically significant detection of clouds on the dayside of a Neptunian-mass
exoplanet. We demonstrate that a highly reflective cloud deck, rather than an extremely high-
metallicity atmosphere, is the most likely explanation for the
planet's anomalously high optical albedo. Furthermore, our atmospheric
retrievals yield robust detections of both CO ($\sim$4.88$\sigma$) and CO$_2$ ($\sim$8.76$\sigma$), while providing tentative constraints on the H$_2$O abundance and upper limits on SiO, TiO, and VO. Finally, our analysis places a robust constraint on the C/O ratio of 0.984 $\pm$ 0.019. This aligns LTT9779b with other known ultra-hot Jupiters exhibiting super-
solar C/O ratios, suggesting a broader trend driven by the sequestration of oxygen-bearing condensates in ultra-hot atmospheres.
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All authors Suman Saha, James S. Jenkins, Jonathan Brande, Reza Ashtari, Ian J. M. Crossfield, Sarah Stamer, Diana Dragomir, Kevin B. Stevenson, Vivien Parmentier, Thomas M. Evans-Soma, Tansu Daylan, Hayley Beltz, Emma Esparza-Borges
Instrumentation and Methods for Astrophysics
Observations of the Cosmic Dawn and Epoch of Reionization with the SKAO: Observational Lessons Learned from Precursors and Pathfinder Instruments
Eloy de Lera Acedo, James Aguirre, Dominic Anstey et al. (+34 more)
This chapter summarizes the observational lessons learned after two decades of observations of the
Cosmic Dawn (CD) and Epoch of Reionization (EoR) with SKAO pathfinders and precursors. We will describe the effort towards building accurate simulation pipelines for actual observations and summarize the approaches that different groups have taken to calibrate and mitigate systematic effects such as sky model incompleteness, limited instrument models and
antenna mutual coupling. We conclude by discussing the impact that these lessons may have on the design and analysis of upcoming SKAO observations of the
Cosmic Dawn and Epoch of Reionization.
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All authors Eloy de Lera Acedo, James Aguirre, Dominic Anstey, Nichole Barry, Gianni Bernardi, Somnath Bharadwaj, Anthony Brown, Jean Cavillot, Suman Chatterjee, Samir Choudhuri, Tyler Cox, John Cumner, Abhirup Datta, Fred Dulwich, Khandakar Md Asif Elahi, Andrew Faulkner, Sukhdeep Singh Gill, Quentin Gueuning, Daniel C. Jacobs, Nicholas Kern, Piyanat Kittiwisit, Yuchen Liu, Zachary Martinot, Ashish Mhaske, Florent Mertens, Vincent McKay, Satyapan Munshi, Steven Murray, Chuneeta D. Nunhokee, Oscar Sage David O'Hara, Samit K. Pal, Robert Pascua, Rashmi Sagar, Shouvik Sarkar, Shiv Sethi, Sarod Yatawatta, Oskar Zetterstrom
Chemical Physics
Converging on bound states in coupled-channel calculations
C. Ruth Le Sueur, James F. E. Croft and Jeremy M. Hutson
We develop a robust
algorithm for locating bound states in coupled-channel calculations. Bound states exist at energies where an individual
eigenvalue of a log-derivative or ratio matching
matrix passes through zero. We describe an
algorithm to identify the required
eigenvalue of the matching
matrix over the full range of energy where it exists. This allows much simpler programming than previous methods. We also consider the choice of the matching distance $R_\textrm{match}$, where the matching
matrix is defined; coupled-channel methods are most efficient if $R_\textrm{match}$ is chosen to be in the classically allowed region for all channels that support bound states of interest, but not very close to a node in the wavefunction.
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