Peer Revenue Publish or profit

Papers

Fresh from arXiv, typeset properly. Highlighted words trade on the market.

Physics

Watch Physics (sign in to use)

Thursday 3 September

Materials Science

Electron-phonon coupled hydrodynamics in semimetal TaAs_2

Hydrodynamic corrections to diffusive transport can arise when momentum-conserving collisions between quasiparticles become prominent, and they have been documented for both electrons and phonons. An emerging frontier topic is coupled electron-phonon (e-ph) hydrodynamics. Here, through electrical and thermal transport measurements on TaAs2 crystals with different impurity levels, we document the emergence of an e-ph bifluid in the temperature window of 5 to 15 K. Within this range, the lattice thermal conductivity exhibits a faster-than-T^3 temperature dependence, as a consequence of non-monotonic and purity-dependent phonon mean free paths, a signature of phonon Poiseuille flow. However, strong e-ph coupling impedes the emergence of a ballistic regime. This is corroborated by the observation of quantum oscillations in the lattice thermal conductivity. Prominent phonon-mediated momentum exchange between electrons amplifies the violation of the Wiedemann-Franz law and yields a two-order-of-magnitude discrepancy between quantum and transport lifetimes, a signature of electron hydrodynamics in semimetals. Our results imply that in semimetals with optimized e-ph coupling, thanks to matching between the cryogenic phonon wave?length and the Fermi wavelength, momentum and energy flow between the electron and phonon reservoirs as frequently as within each reservoir.
Read the full abstract

All authors Shan Jiang, Wei Xie, Xiaokang Li, Kamran Behnia, Zengwei Zhu

Strongly Correlated Electrons

Competing lattice structures induced by Sn substitution in CsV$_3$Sb$_5$

Understanding the effect of chemical substitution on competing phases of kagome metals is crucial for disentangling the interplay between local structural distortions and electronic instabilities. In \cvs, Sn substitution strongly modifies the electronic phase diagram, yet the microscopic mechanism driving this remains unclear. Here, we combine $^{121}$Sb nuclear quadrupole resonance (NQR) measurements and density functional theory calculations to investigate the atomic-scale effects of Sn substitution in CsV$_3$Sb$_{5-x}$Sn$_x$. At low Sn concentrations, the observed satellite NQR peaks exhibit signatures of local structural distortion induced by Sn substitution, qualitatively consistent with our computational analysis. These impurity-induced features persist across the entire experimentally investigated doping range, up to $x$ = 0.65, and remain observable up to room temperature. For $x=1$, the fully doped idealized case, the estimated dynamical instabilities of the kagome lattice suggest the stabilization of two nearly energy-degenerate equilibrium structures characterized by V-trimers, distinguished by a zero- or $\pi$-phase shift between adjacent layers along the $c$-axis. Together, these results show that Sn substitution drives a complex interplay between local impurity-induced distortions and competing structural instabilities in vanadium-based kagome compounds.
Read the full abstract

All authors Anshu Kataria, Ilija K. Nikolov, Armando Consiglio, Giuseppe Allodi, Ginevra Corsale, Andrea Capa Salinas, Stephen D. Wilson, Domenico Di Sante, Vesna F. Mitrović, Samuele Sanna, Pietro Bonfà

Materials Science

Interplay of B-Site Off-Centering and Molecular Orientations in the Mixed Hybrid Perovskite MAGe1xSnxI3

B-site mixing is a common strategy for tuning properties of halide perovskites. In the lead-free system MAGe1-xSn_xI3, it brings tilting and off-centering into competition. Using large-scale molecular dynamics driven by a machine-learned interatomic potential, we map the structural behavior across the full composition range. MAGeI3 exhibits strong polar B-site off-centering that remains nearly constant up to the cubic transition, together with methylammonium (MA) orientational order that weakens progressively on heating. By contrast, MASnI3 combines octahedral tilting with weaker, predominantly antipolar off-centering. Ge-like behavior persists upon alloying and gives way to Sn-like behavior only beyond roughly 65 % Sn. In the high-temperature phases, the B-site cations remain locally off-centered but directionally disordered. On the Ge-rich side, the distorted inorganic framework biases the soft MA orientational landscape toward a restricted set of preferred directions. This coupling shows how the composition of the inorganic sublattice can tune molecular ordering in lead-free hybrid perovskites.
Read the full abstract

All authors Erik Fransson, Apinya Ngoipala, Oskar Öjstedt, Maths Karlsson, Paul Erhart, Julia Wiktor

Fluid Dynamics

A conservative coupling method of sharp-interface and multi-species model for compressible reacting gas-liquid flows with phase change

In this paper, a conservative sharp-interface and diffuse-interface coupling method is developed for compressible two-phase multi-species flows with phase change and chemical reactions. The liquid–gas interface is represented by a sharp-interface model, whereas a diffuse-interface model treats the transport and chemical reactions of gas-phase species. Conservation is enforced by coupling the two phases through interfacial fluxes obtained from a multi-species phase-change Riemann problem. The original single-species four-wave Riemann solver is extended to multi-species gas mixtures by modifying the interfacial energy jump condition. Interfacial mass transfer is restricted to the condensable vapor species. Accordingly, both the interfacial energy jump condition and the gas-mixture energy-exchange flux are constructed using the internal energy of the phase-changing vapor species rather than the mixture internal energy. With this species-selective energy coupling, an approximate multi-species Riemann solver is constructed that retains the four-wave structure while avoiding the multidimensional nonlinear root-finding required by the exact solution. A series of numerical tests, including impulsive evaporation and condensation, reacting aluminum vaporization, shock-droplet interaction, and detonation-droplet interaction, are performed to assess the accuracy and robustness of the method. The numerical results agree well with reference solutions and benchmark data, demonstrating that the present method resolves the effects of phase change and chemical reactions in compressible multi-species multiphase flows while preserving conservative interfacial coupling.
Read the full abstract

Soft Condensed Matter

Exact Scaling Laws and Non-Hermitian Topological Phase Transitions of Active Continuum on Hyperbolic Manifolds

The macroscopic collective motion of active continuum on curved manifolds is conventionally addressed through perturbative dynamic renormalization or finite-element simulations, often obscuring the underlying geometric mechanisms. Here, an exact algebraic framework is established to reformulate the active phase transition on hyperbolic spaces $\mathbb{H}^2$. By rigorously expanding the covariant Navier-Stokes-like equations and applying the Weitzenböck identity, we derive the exact critical threshold $\alpha_c = \frac{5}{4}D\kappa^2$ for macroscopic polarization, which is dictated by the geometric mass gap of the Hodge-de Rham Laplacian. We strictly define the parameter subspace $\alpha = 2D\kappa^2$ where the topological free energy reaches the Bogomolny-Prasad-Sommerfield (BPS) limit. This enables the reduction of the complex velocity field to Blaschke products via Möbius gauge symmetry. The flat-space limit ($\kappa \to 0$) exactly degenerates to the topological phase of the classical O(2) model, demonstrating that the constant negative curvature acts as an un-perturbative infrared regularization for non-linear amplitude saturation. Furthermore, mapping the non-variational active convective modes onto the defect translational zero-modes yields an intrinsically non-reciprocal interaction matrix. By analytically extending the singular integral operator of the dynamically condensed defect ring, we identify a macroscopic second-order exceptional point (EP2) characterized by a strictly algebraic dynamic scaling law $\tau \sim |\Delta \nu|^{-1/2}$. This closed-form theoretical paradigm provides exact solutions for geometric frustration and non-Hermitian topology in soft mechanics.
Read the full abstract

Nuclear Theory

A Practical Partial-Wave Method for Identifying Unstable Light Nucleus Resonances in Heavy-Ion Collisions

The production of light nuclei in relativistic heavy-ion collisions provides valuable insights into the dynamics of the hot and dense matter created in these extreme environments. While stable light nuclei have been extensively studied, unstable light nuclei being short-lived resonance states remain largely unexplored and offer unique opportunities to probe final-state interactions and the freeze-out conditions. In this paper, we propose a partial-wave method, based on the Lednický–Lyuboshitz framework, to extract resonance signals of unstable light nuclei from two-particle correlation functions measured in heavy-ion collisions. By extending the LL model to higher order partial waves and directly incorporating experimental phase-shift data from low-energy nuclear scattering, our approach avoids the need for model-dependent potential parametrizations and enables a clean decomposition of the resonant partial wave from the non-resonant background. As a demonstration, we apply the method to the $p$-$^3$He and $p$-$^4$He systems, corresponding to the $^4$Li and $^5$Li ground-state resonances. Numerical results show that the resonance-induced correlation excess can be effectively isolated, with a peak in the correlation function appearing at $k \approx 72$ MeV/$c$ for $^4$Li and $k \approx 50$ MeV/$c$ for $^5$Li, consistent with the known resonance parameters. The extracted transverse momentum spectra and rapidity distributions are presented using the measured proton and light-nuclei spectra from STAR at $\sqrt{s_{NN}} = 3$ GeV. The proposed method provides a practical tool for the experimental study of unstable light nuclei in relativistic heavy-ion collisions and can be extended to a broader range of resonance states.
Read the full abstract

All authors Junlin Wu, Hongchan Li, Ke Mi, Yaping Wang, Guannan Xie

Quantum Physics

Topology-Dependent Enhancement of Entanglement Extraction in Repeater Graph States

Quantum repeaters are essential for establishing long-distance quantum communication to overcome the exponential decay of entanglement due to photon loss. Traditional repeater architectures rely on physical quantum memory, which introduces decoherence and poses significant practical implementation challenges. The repeater graph state (RGS) architecture offers a promising memory-less alternative that is inherently resilient to photon losses. A key challenge in implementing RGS lies in the requirement for highly efficient graph state generators and complex qubit measurement. In this work, we aim to investigate the strategies for extracting the maximum number of Bell pairs from the RGS structure via its qubit connection to resolve the well-known bottleneck problem of RGS in which only a single Bell pair can be extracted from a complete bipartite graph state. From simulations, we observe that the maximum number of extracted Bell pairs depends on its connection topology, where the Bell-pair yield tends to be maximal at low to moderate edge densities. As the number of network hops increases, the RGS must be equipped with higher inner-qubit connectivity to maintain a sufficient yield of extractable Bell pairs. Thus, the expected resource requirement shifts toward the use of RGSs with higher inner-qubit connectivity.
Read the full abstract

All authors Poramat Chianvichai, Poramet Pathumsoot, Naphan Benchasattabuse, Michal Hajdušek, Rodney Van Meter, Sujin Suwanna

Quantum Physics

Weakly Driven and Finite Detuning Boundary Time Crystals Enabled by Low-Dissipation Dynamical Channels

Spontaneous breaking of continuous time-translation symmetry in driven-dissipative systems gives rise to boundary time crystals (BTCs), characterized by persistent oscillations sustained by coherent driving and collective dissipation. Conventional BTCs, however, typically require strong driving and exact atom-drive resonance, imposing stringent constraints on their realization. Here we consider two atomic ensembles coupled to a common Markovian reservoir and show that shared dissipation organizes dissipation-free and low-dissipation modes into dynamically accessible low-dissipation channels, enabling BTCs under weak driving and finite detuning. Finite detuning further selects a unique stable limit cycle from an initial-state-dependent family of oscillatory trajectories. Our results establish low-dissipation dynamical channels as a route to robust BTCs under relaxed driving and resonance conditions.
Read the full abstract

Strongly Correlated Electrons

Such stuff as magic is made on: compact operator algebra, stabilizer polytope and the structure of reduced density matrices in a Kitaev spin liquid

Quantum many-body systems exhibit rich and complex behaviour. Magic has recently emerged as a powerful new diagnostic for probing such systems, complementing other key features such as many-body entanglement. Here, starting from an investigation of the onset of magic within subsystems of a larger many-body quantum system, we show that intricate structures emerge which shed important light on the underlying many-body physics. Focusing on the Kitaev honeycomb model, we first identify the temperature below which local subsystems acquire magic. Remarkably, we find that the optimal magic witnesses active at the onset of magic reveal compact operator spaces that continue to capture the local thermal states throughout their subsequent evolution. For the six-site hexagonal marginal, this connection can be made stronger: the same operator space emerges independently from the symmetries of the local marginal and forms the symmetry-resolved plaquette algebra. When these symmetries are realized exactly, the local state lies entirely within this algebra and the reduced robustness of magic is equal to the full robustness of magic. The same reduced description can also be applied to other local quantum resources, which we illustrate using genuine multipartite entanglement. Furthermore, the operator spaces possess a rich algebraic structure in the form of finite-dimensional Euclidean Jordan algebras, with a natural interpretation in terms of bond and bond-cycle operators. Our general methodology therefore show how the onset of local magic can reveal a compact, physically meaningful operator structure underlying the finite-temperature Kitaev spin liquid, and opens up a new avenue towards reduced descriptions of quantum resources in many-body systems.
Read the full abstract

Plasma Physics

Dependence of self-injected bunch parameters on the plasma density gradient and laser pulse amplitude at LWFA in a conical plasma channel

Laser wakefield acceleration (LWFA) is an advanced method of high gradient acceleration of charged particles with wakefield excited in plasma by laser pulse. A distinctive feature of this method is the ability to create and accelerate so-called self-injected bunches with unique parameters - charge, energy, emittance, and geometric dimensions - without the need for an external injector of the required bunches for their subsequent acceleration to higher energies. Self-injected bunches emerge due to the plasma electrons trapping by the excited wakefield (self-injection phenomenon). For many applications, self-injected bunches can be used directly in relevant experiments. In this paper the dependence of the self-injected bunch parameters on the laser pulse amplitude and longitudinal gradient of plasma density in tapered plasma channel is investigated using numerical simulation with the WarpX code. At the laser amplitude $a_0=E_0(m_{e0}c\omega/e)^{-1}=3.6$ in a conical channel with the radius decreasing from $4.0\,c/\omega_{pe}$ to $2.16\,c/\omega_{pe}$ and with the plasma density increasing linearly from $n_e=2.61\cdot10^{19}$ cm$^{-3}$ at the channel entrance to $3n_e$ at the exit, a self-injected bunch is obtained with the charge $32.1\,\mu$C/m, the mean longitudinal momentum $111.9\,m_ec$, the length $5.10\,\mu$m, the area $5.3\,\mu$m$^2$, the transverse emittance $1.6\cdot10^{-2}$ mm$\cdot$mrad.
Read the full abstract

General Relativity and Quantum Cosmology

Dynamical Selection of Horizon-BMS Goldstone Modes in Evaporating Black Holes

We investigate the dynamics of horizon soft degrees of freedom associated with near-horizon BMS supertranslations in an evaporating Vaidya-Schwarzschild black hole spacetime. Considering the dynamic nature of the supertranslation parameter, we derive its effective action directly from the Einstein-Hilbert action. The resulting Goldstone sector is intrinsically coupled to the evolving black hole dynamics, with the mass function entering the evolution of the Goldstone modes while the Goldstone configuration contributes to the dynamical evolution of the black hole mass. Azimuthal periodicity and regularity at the poles select the physically admissible angular sector and yields a mass-dependent $selection\ rule$ on the azimuthal modes. Consequently, the spectrum of horizon-supported Goldstone modes evolves with the black hole mass; as the horizon shrinks during evaporation, the horizon is left with a progressively reduced set of lower-order modes. The evaporation thus induces a dynamical filtering of the horizon soft sector, arising intrinsically from the black hole mass dynamics. These results provide an effective gravitational framework linking near-horizon BMS symmetry, dynamical Goldstone modes, and black hole evaporation, suggesting a direct connection between macroscopic horizon evolution with the microscopic organization of the gravitational soft degrees of freedom residing on the horizon.
Read the full abstract

Mesoscale and Nanoscale Physics

Built-In Electric Field Modulation of Spontaneous Magnetism and Thermospin Transport in Boron-Nitrogen Doped Zigzag Graphene Nanoribbons

Zigzag-edged graphene nanoribbons (ZGNRs) host large magnetic moments at two zigzag edges due to spontaneous magnetism, whose ground state is antiferromagnetically coupled spin-order edge state (AF state). In this paper, the spontaneous magnetism and thermoelectricity of ZGNRs with periodic substituted doping of boron and nitrogen atoms along the axial direction are investigated by first principle calculation. The doping induces an internal electric field, which modulates the magnetic moments at the two zigzag edges and the band structure with spin splitting. For varying doping configuration, the ground state could be AF state, ferromagnetically coupled spin-order edge state (FM state), or degenerated pair of AF and FM states. External transversal static electric field can further modulate the magnetic moments and the band structure. By designing the doping configuration and the external field, pure thermal spin current with the absence of thermal charge current can be generated at room temperature, which can be switched on and off by flipping the magnetic configuration between AF and FM states. Thus, the doped ZGNRs can be applied as prototype devices for spin-caloritronic.
Read the full abstract

Soft Condensed Matter

Granular Rods Fall Faster in Denser Obstacle Fields

How does particle shape affect driven transport through obstacle fields? We simulate a dissipative rod falling under gravity through randomly placed fixed obstacles. For sufficiently slender rods, the mean descent speed before trapping decreases, increases, and then decreases again as obstacle density rises, opening a window of densities in which rods fall faster in denser fields. Scaling arguments based on collision rates and rod geometry explain the three regimes and their crossovers. Particle shape can thus reverse the expectation that crowding slows driven transport.
Read the full abstract

Strongly Correlated Electrons

Studying line defect at Deconfined Quantum Criticality via fuzzy sphere regularization

The interplay between bulk critical fluctuations and nontrivial topology can enrich defect physics and give rise to novel defect universality classes. Understanding the fate of such defects therefore constitutes an important open problem. In this work, we studied a particularly simple setting: a (0+1)-dimensional pinning-field defect coupled to a (2+1)-dimensional deconfined quantum critical bulk. Using the fuzzy-sphere regularization, we numerically investigated the defect operator spectrum and extracted several universal quantities characterizing the defect conformal fixed point, including the scaling dimensions of defect-changing(creating) operators and the defect \(g\)-function. These results establish the first numerical characterization of line-defect conformal data at deconfined quantum criticality and may stimulate further investigations of defect critical phenomena in topological quantum critical matter.
Read the full abstract

All authors Shutao Liu, Shuai Yang, Jie Lou, Yan Chen

High Energy Physics (Experiment)

Study of $K_{S}^{0}$-$K_{L}^{0}$ asymmetry in the decays $D^0 \to K_{S}^{0}\omega $ and $D^0 \to K_{L}^{0} \omega $

Based on $e^+ e^-$ annihilation data corresponding to an integrated luminosity of 7.93~$fb^{-1}$ collected at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider, the absolute branching fractions of the decays $D^0 \to K_{S}^{0} \omega$ and $D^0 \to K_{L}^{0} \omega $ are measured to be $(11.79 \pm 0.19 \pm 0.26 \pm 0.47) \times 10^{-3}$ and ($10.84 \pm 0.14 \pm 0.23 \pm 0.44) \times 10^{-3}$, respectively. The $K_{S}^{0}- K_{L}^{0}$ branching-fraction asymmetry of these two decays is $R(D^0,K_{S,L}^{0} \omega) = \frac{\mathcal{B}(D^0 \to K_{S}^{0} \omega) - \mathcal{B}(D^0 \to K_{L}^{0}\omega )}{\mathcal{B}(D^0 \to K_{S}^{0} \omega) + \mathcal{B}(D^0 \to K_{L}^{0} \omega)} =(4.2 \pm 1.0 \pm 0.9 \pm 2.8)\%$. Here, the first uncertainties are statistical, the second systematic, and the third arise from the interference between $D^0 \to K_{S,L}^{0} \omega$ and the non-resonant $D^0 \to \pi^+ \pi^- \pi^0 K_{S,L}^{0}$ processes.
Read the full abstract

All authors BESIII Collaboration: M. Ablikim, M. N. Achasov, P. Adlarson, X. C. Ai, C. S. Akondi, R. Aliberti, A. Amoroso, Q. An, Y. H. An, Y. Bai, O. Bakina, H. R. Bao, X. L. Bao, M. Barbagiovanni, V. Batozskaya, K. Begzsuren, N. Berger, M. Berlowski, M. B. Bertani, D. Bettoni, F. Bianchi, E. Bianco, A. Bortone, I. Boyko, R. A. Briere, A. Brueggemann, D. Cabiati, H. Cai, M. H. Cai, X. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Cetin, X. Y. Chai, J. F. Chang, T. T. Chang, G. R. Che, Y. Z. Che, C. H. Chen, Chao Chen, G. Chen, H. S. Chen, H. Y. Chen, M. L. Chen, S. J. Chen, S. M. Chen, T. Chen, W. Chen, X. R. Chen, X. T. Chen, X. Y. Chen, Y. B. Chen, Y. Q. Chen, Z. K. Chen, J. Cheng, L. N. Cheng, S. K. Choi, X. Chu, G. Cibinetto, F. Cossio, J. Cottee-Meldrum, H. L. Dai, J. P. Dai, X. C. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, C. Q. Deng, Z. Y. Deng, A. Denig, I. Denisenko, M. Destefanis, F. De Mori, E. Di Fiore, X. X. Ding, Y. Ding, Y. X. Ding, Yi. Ding, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, M. C. Du, S. X. Du, Shaoxu Du, X. L. Du, Y. Q. Du, Y. Y. Duan, Z. H. Duan, P. Egorov, G. F. Fan, J. J. Fan, Y. H. Fan, J. Fang, Jin Fang, S. S. Fang, W. X. Fang, Y. Q. Fang, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, J. H. Feng, L. Feng, Q. X. Feng, Y. T. Feng, M. Fritsch, C. D. Fu, J. L. Fu, Y. W. Fu, H. Gao, Xu Gao, Y. Gao, Y. N. Gao, Y. Y. Gao, Yunong Gao, Z. Gao, S. Garbolino, I. Garzia, L. Ge, P. T. Ge, Z. W. Ge, C. Geng, E. M. Gersabeck, A. Gilman, K. Goetzen, J. Gollub, J. B. Gong, J. D. Gong, L. Gong, W. X. Gong, W. Gradl, S. Gramigna, M. Greco, M. D. Gu, M. H. Gu, C. Y. Guan, A. Q. Guo, H. Guo, J. N. Guo, L. B. Guo, M. J. Guo, R. P. Guo, X. Guo, Y. P. Guo, Z. Guo, A. Guskov, J. Gutierrez, J. Y. Han, T. T. Han, X. Han, F. Hanisch, K. D. Hao, X. Q. Hao, F. A. Harris, C. Z. He, K. K. He, K. L. He, F. H. Heinsius, C. H. Heinz, Y. K. Heng, C. Herold, P. C. Hong, G. Y. Hou, X. T. Hou, Y. R. Hou, Z. L. Hou, H. M. Hu, J. F. Hu, Q. P. Hu, S. L. Hu, T. Hu, Y. Hu, Y. X. Hu, Z. M. Hu, G. S. Huang, K. X. Huang, L. Q. Huang, P. Huang, X. T. Huang, Y. P. Huang, Y. S. Huang, T. Hussain, N. Hüsken, N. in der Wiesche, J. Jackson, Q. Ji, Q. P. Ji, W. Ji, X. B. Ji, X. L. Ji, Y. Y. Ji, L. K. Jia, X. Q. Jia, D. Jiang, H. B. Jiang, S. J. Jiang, X. S. Jiang, Y. Jiang, J. B. Jiao, J. K. Jiao, Z. Jiao, L. C. L. Jin, S. Jin, Y. Jin, M. Q. Jing, X. M. Jing, T. Johansson, S. Kabana, X. L. Kang, X. S. Kang, B. C. Ke, V. Khachatryan, A. Khoukaz, O. B. Kolcu, B. Kopf, L. Kröger, L. Krümmel, Y. Y. Kuang, M. Kuessner, X. Kui, N. Kumar, A. Kupsc, W. Kühn, Q. Lan, W. N. Lan, T. T. Lei, M. Lellmann, T. Lenz, C. Li, C. H. Li, C. K. Li, Chunkai Li, Cong Li, D. M. Li, F. Li, G. Li, H. B. Li, H. J. Li, H. L. Li, H. N. Li, H. P. Li, Hui Li, J. N. Li, J. S. Li, J. W. Li, K. Li, K. L. Li, L. J. Li, Lei Li, M. H. Li, M. R. Li, M. T. Li, P. L. Li, P. R. Li, Q. M. Li, Q. X. Li, R. Li, S. Li, S. X. Li, S. Y. Li, Shanshan Li, T. Li, T. Y. Li, W. D. Li, W. G. Li, X. Li, X. H. Li, X. K. Li, X. L. Li, X. Y. Li, X. Z. Li, Y. Li, Y. G. Li, Y. P. Li, Z. H. Li, Z. J. Li, Z. L. Li, Z. X. Li, Z. Y. Li, C. Liang, H. Liang, Y. F. Liang, Y. T. Liang, G. R. Liao, L. B. Liao, M. H. Liao, Y. P. Liao, J. Libby, A. Limphirat, C. C. Lin, C. X. Lin, D. X. Lin, T. Lin, B. J. Liu, B. X. Liu, C. Liu, C. X. Liu, F. Liu, F. H. Liu, Feng Liu, G. M. Liu, H. Liu, H. B. Liu, H. M. Liu, Huihui Liu, J. B. Liu, J. J. Liu, K. Liu, K. Y. Liu, Ke Liu, Kun Liu, L. Liu, L. C. Liu, Lu Liu, M. H. Liu, P. L. Liu, Q. Liu, S. B. Liu, T. Liu, W. M. Liu, W. T. Liu, X. Liu, X. K. Liu, X. L. Liu, X. P. Liu, X. Y. Liu, Y. Liu, Y. B. Liu, Yi Liu, Z. A. Liu, Z. D. Liu, Z. L. Liu, Z. Q. Liu, Z. X. Liu, Z. Y. Liu, X. C. Lou, H. J. Lu, J. G. Lu, X. L. Lu, Y. Lu, Y. H. Lu, Y. P. Lu, Z. H. Lu, C. L. Luo, J. R. Luo, J. S. Luo, M. X. Luo, T. Luo, X. L. Luo, Z. Y. Lv, X. R. Lyu, Y. F. Lyu, Y. H. Lyu, F. C. Ma, H. L. Ma, Heng Ma, J. L. Ma, L. L. Ma, L. R. Ma, Q. M. Ma, R. Q. Ma, R. Y. Ma, T. Ma, X. T. Ma, X. Y. Ma, Y. M. Ma, F. E. Maas, I. MacKay, M. Maggiora, S. Maity, S. Malde, Q. A. Malik, H. X. Mao, Y. J. Mao, Z. P. Mao, S. Marcello, A. Marshall, F. M. Melendi, Y. H. Meng, Z. X. Meng, G. Mezzadri, H. Miao, T. J. Min, R. E. Mitchell, X. H. Mo, B. Moses, N. Yu. Muchnoi, J. Muskalla, Y. Nefedov, F. Nerling, H. Neuwirth, Z. Ning, S. Nisar, Q. L. Niu, W. D. Niu, Y. Niu, C. Normand, S. L. Olsen, Q. Ouyang, S. Pacetti, X. Pan, Y. Pan, A. Pathak, Y. P. Pei, M. Pelizaeus, G. L. Peng, H. P. Peng, X. J. Peng, Y. Y. Peng, K. Peters, K. Petridis, J. L. Ping, R. G. Ping, S. Plura, V. Prasad, L. Pöpping, F. Z. Qi, H. R. Qi, M. Qi, S. Qian, W. B. Qian, C. F. Qiao, J. H. Qiao, J. J. Qin, J. L. Qin, L. Q. Qin, L. Y. Qin, P. B. Qin, X. P. Qin, X. S. Qin, Z. H. Qin, J. F. Qiu, Z. H. Qu, J. Rademacker, K. Ravindran, C. F. Redmer, A. Rivetti, M. Rolo, G. Rong, S. S. Rong, F. Rosini, Ch. Rosner, M. Q. Ruan, N. Salone, A. Sarantsev, Y. Schelhaas, M. Schernau, K. Schoenning, M. Scodeggio, W. Shan, X. Y. Shan, Z. J. Shang, J. F. Shangguan, L. G. Shao, M. Shao, C. P. Shen, H. F. Shen, W. H. Shen, X. Y. Shen, B. A. Shi, Ch. Y. Shi, H. Shi, J. L. Shi, J. Y. Shi, M. H. Shi, S. Y. Shi, X. Shi, H. L. Song, J. J. Song, M. H. Song, T. Z. Song, W. M. Song, Y. X. Song, Zirong Song, S. Sosio, S. Spataro, S. Stansilaus, F. Stieler, M. Stolte, S. S Su, G. B. Sun, G. X. Sun, H. Sun, H. K. Sun, J. F. Sun, K. Sun, L. Sun, R. Sun, S. S. Sun, T. Sun, W. Y. Sun, Y. C. Sun, Y. H. Sun, Y. J. Sun, Y. Z. Sun, Z. Q. Sun, Z. T. Sun, H. Tabaharizato, C. J. Tang, G. Y. Tang, J. Tang, J. J. Tang, L. F. Tang, Y. A. Tang, Z. H. Tang, L. Y. Tao, M. Tat, J. X. Teng, J. Y. Tian, W. H. Tian, Y. Tian, Z. F. Tian, I. Uman, E. van der Smagt, B. Wang, Bin Wang, Bo Wang, C. Wang, Chao Wang, Cong Wang, D. Y. Wang, H. J. Wang, H. R. Wang, J. Wang, J. J. Wang, J. P. Wang, K. Wang, L. L. Wang, L. W. Wang, M. Wang, Mi Wang, N. Y. Wang, S. Wang, Shun Wang, T. Wang, W. Wang, W. P. Wang, X. F. Wang, X. L. Wang, X. N. Wang, Xin Wang, Y. Wang, Y. D. Wang, Y. F. Wang, Y. H. Wang, Y. J. Wang, Y. L. Wang, Y. N. Wang, Yanning Wang, Yaqian Wang, Yi Wang, Yuan Wang, Z. Wang, Z. L. Wang, Z. Q. Wang, Z. Y. Wang, Zhi Wang, Ziyi Wang, D. Wei, D. H. Wei, D. J. Wei, H. R. Wei, F. Weidner, H. R. Wen, S. P. Wen, U. Wiedner, G. Wilkinson, M. Wolke, J. F. Wu, L. H. Wu, L. J. Wu, Lianjie Wu, S. G. Wu, S. M. Wu, X. W. Wu, Z. Wu, H. L. Xia, L. Xia, B. H. Xiang, D. Xiao, G. Y. Xiao, H. Xiao, Y. L. Xiao, Z. J. Xiao, C. Xie, K. J. Xie, Y. Xie, Y. G. Xie, Y. H. Xie, Z. P. Xie, T. Y. Xing, D. B. Xiong, C. J. Xu, G. F. Xu, H. Y. Xu, Q. J. Xu, Q. N. Xu, T. D. Xu, X. P. Xu, Y. Xu, Y. C. Xu, Z. S. Xu, F. Yan, L. Yan, W. B. Yan, W. C. Yan, W. H. Yan, W. P. Yan, X. Q. Yan, Y. Y. Yan, H. J. Yang, H. L. Yang, H. X. Yang, J. H. Yang, R. J. Yang, X. Y. Yang, Y. Yang, Y. H. Yang, Y. M. Yang, Y. Q. Yang, Y. Z. Yang, Youhua Yang, Z. Y. Yang, W. J. Yao, Z. P. Yao, M. Ye, M. H. Ye, Z. J. Ye, Junhao Yin, Z. Y. You, B. X. Yu, C. X. Yu, G. Yu, J. S. Yu, L. W. Yu, T. Yu, X. D. Yu, Y. C. Yu, Yongchao Yu, C. Z. Yuan, H. Yuan, J. Yuan, Jie Yuan, L. Yuan, M. K. Yuan, S. H. Yuan, Y. Yuan, C. X. Yue, Ying Yue, A. A. Zafar, F. R. Zeng, S. H. Zeng, X. Zeng, Y. J. Zeng, Yujie Zeng, Y. C. Zhai, Y. H. Zhan, B. L. Zhang, B. X. Zhang, D. H. Zhang, G. Y. Zhang, Gengyuan Zhang, H. Zhang, H. C. Zhang, H. H. Zhang, H. Q. Zhang, H. R. Zhang, H. Y. Zhang, Han Zhang, J. Zhang, J. J. Zhang, J. L. Zhang, J. Q. Zhang, J. S. Zhang, J. W. Zhang, J. X. Zhang, J. Y. Zhang, J. Z. Zhang, Jianyu Zhang, Jin Zhang, Jiyuan Zhang, L. M. Zhang, Lei Zhang, N. Zhang, P. Zhang, Q. Zhang, Q. Y. Zhang, Q. Z. Zhang, R. Y. Zhang, S. H. Zhang, S. N. Zhang, Shulei Zhang, X. M. Zhang, X. Y. Zhang, Y. Zhang, Y. T. Zhang, Y. H. Zhang, Y. P. Zhang, Yu Zhang, Z. Zhang, Z. D. Zhang, Z. H. Zhang, Z. L. Zhang, Z. X. Zhang, Z. Y. Zhang, Zh. Zh. Zhang, Zhilong Zhang, Ziyang Zhang, Ziyu Zhang, G. Zhao, J.-P. Zhao, J. Y. Zhao, J. Z. Zhao, L. Zhao, Lei Zhao, M. G. Zhao, R. P. Zhao, S. J. Zhao, Y. B. Zhao, Y. L. Zhao, Y. P. Zhao, Y. X. Zhao, Z. G. Zhao, A. Zhemchugov, B. Zheng, B. M. Zheng, J. P. Zheng, W. J. Zheng, W. Q. Zheng, X. R. Zheng, Y. H. Zheng, B. Zhong, C. Zhong, H. Zhou, J. Q. Zhou, S. Zhou, X. Zhou, X. K. Zhou, X. R. Zhou, X. Y. Zhou, Y. X. Zhou, Y. Z. Zhou, A. N. Zhu, J. Zhu, K. Zhu, K. J. Zhu, K. S. Zhu, L. X. Zhu, Lin Zhu, S. H. Zhu, T. J. Zhu, W. D. Zhu, W. J. Zhu, W. Z. Zhu, Y. C. Zhu, Z. A. Zhu, X. Y. Zhuang, M. Zhuge, J. H. Zou, J. Zu

Astrophysics of Galaxies

Magnetic Fields in Massive Star-forming Regions (MagMaR). IX. Radiative Torque Alignment and Disruption in NGC6334I

Intense radiation from high-mass stars is expected to significantly affect dust grain alignment and evolution through RAdiative Torques (RATs). We investigate this effect in a massive star-forming region, NGC6334I, using 1.2 mm dust continuum polarization observations from the Atacama Large Millimeter/submillimeter Array. The polarization fraction spans from $\lesssim1\%$ to $\sim10\%$ and decreases with increasing column density, remaining below $2\%$ in dense cores despite high temperatures ($\sim100$ K), where efficient grain alignment by RATs is expected. We investigate how grain alignment, grain growth, grain disruption, B-field tangling, and local physical conditions affect the polarization properties of MM1, MM2, MM3, and their surroundings. Polarization angle dispersion shows that B-field tangling contributes to depolarization at moderate densities but cannot fully explain the lowest polarization fractions. Using RAT-based grain alignment and polarization modeling, we find that reduced alignment efficiency and high optical depth reproduce the low polarization in the densest regions. MM2 shows evidence of grain growth, with maximum grain sizes $a_{\max}\sim0.35-1.0~\mu$m, while MM1 exhibits smaller values of $\sim0.35-0.50~\mu$m. Accounting for optical depth increases the inferred grain sizes in MM1 to $\sim1.0-2.0~\mu$m. Analytical estimates of radiative torque disruption from the intense outburst suggest that micron-sized grains in high-temperature, moderate-density regions can fragment into submicron grains. Alternatively, high optical depth may also explain the low polarization in the densest regions even in the presence of micron-sized grains. Incorporating the B-field inclination effect indicates a transition from predominantly plane-of-sky fields at low densities to more line-of-sight-aligned configurations at high densities.
Read the full abstract

All authors Vineet Rawat, Thiem Hoang, Patricio Sanhueza, Ian W. Stephens, Manuel Fernández López, Paulo Cortés, Jihye Hwang, Junhao Liu, Kaho Morii, Josep Miquel Girart, Ji-Hyun Kang, Yu Cheng, Shanghuo Li, Luis A. Zapata, Eun Jung Chung, Fernando A. Olguin, Huei-Ru Vivien Chen, Piyali Saha, Chakali Eswaraiah, Qizhou Zhang, O.R. Jadhav

High Energy Astrophysical Phenomena

Gamma-Ray Bursts and Optical Brightness: Insights from Swift Satellite

During the examination of optical properties of gamma-ray bursts (GRBs) measured during the life of the Neil Gehrels Swift Observatory satellite, significant discoveries were made. While the satellite measures gamma, X-ray, and optical data simultaneously, in many cases, only an upper limit is established in the optical domain. Hence, survival analysis, a.k.a. dependability modelling, was necessary, serving as a tool for studying samples where some cases are bound only by the upper limit, as mentioned earlier. This method is used to analyse datasets that may have upper or lower bounds rather than precise observations, but nevertheless contain relevant information. It was previously established that the duration, gamma fluence, and peak flux all have a substantial effect on the optical brightness distribution, probably due to the energy of the beam from the GRB's central engine. However, after analysing more than 200 data points, we no longer see this association. This disagreement shows that the previously reported impact may not be as significant as previously derived, needing more research to better understand the underlying processes that determine the optical brightness in connection to gamma-ray properties.
Read the full abstract

Quantum Physics

Convolution absorbing boundaries for explicit-circuit quantum simulation of the wave equation

Explicit quantum circuits for the wave equation, built by Hamiltonian simulation, are restricted to closed domains, in which outgoing waves reflect off the edge of the computational region and return. We lift that restriction with absorbing boundaries of the convolution type - a complex-frequency-shifted perfectly matched layer realised through exponential-kernel memory variables - and make the resulting non-unitary dynamics quantum-implementable by Schrodingerisation. We obtain three results. First, explicit gate-level circuits for the absorbing evolution, obtained by extending a Bell- basis term-evolution circuit to projector-valued operator strings and Trotterising to second order; these run end to end on seventeen to twenty-one qubits and agree with exact references to within a tenth of a percent to a percent. Second, a structural obstruction: the memory form of the absorbing generator carries an irreducibly indefinite Hermitian part, whose largest eigenvalue grows as the square root of the absorption strength divided by the grid spacing and survives any diagonal rescaling of the memory fields. The known recovery threshold for Schrodingerisation then makes the post-selection cost grow exponentially in the simulated time. Third, a remedy: a Lyapunov symmetrizer, precomputed classically, renders the transformed generator dissipative and replaces that time-dependent penalty with a time-independent conditioning factor of several hundred, measured on grids of up to four thousand unknowns and saturating under mesh refinement. The crossover is early: past it the symmetrized recovery is cheaper by four to twenty-six orders of magnitude in post-selection cost, and at the longest horizons tested it is the only recovery that works.
Read the full abstract

High Energy Astrophysical Phenomena

The Jet Properties and Accretion Regime for the Blazar Sequence

The puzzling bimodality displayed by blazars on the broad-band spectral indices ($\alpha_{\rm ro}-\alpha_{\rm ox}$) plane is still an open question. To investigate its physical origin, we compiled a sample comprising 136 flat-spectrum radio quasars (FSRQs), 64 low-synchrotron-peaked BL Lac objects (LBLs), 39 intermediate-synchrotron-peaked BL Lac objects (IBLs), and 105 high-synchrotron-peaked BL Lac objects (HBLs). Our results show that (FSRQs+LBLs)$\rightarrow$IBLs$\rightarrow$HBLs follow a \reflectbox{$\angle$}-shaped evolutionary sequence on the $\alpha_{\rm ro}-\alpha_{\rm ox}$ plane, with the average 5\,GHz radio Doppler factor, jet power, and accretion Eddington ratio decreasing along this \reflectbox{$\angle$}-shaped track. Additionally, the distributions of $\alpha_{\rm ox}$ exhibit only slight differences among blazar subclasses, whereas those of $\alpha_{\rm ro}$ and $\alpha_{\rm rx}$ differ significantly. Our results can be naturally explained if the distribution of blazars on the $\alpha_{\rm ro}-\alpha_{\rm ox}$ plane is regulated by the accretion rates and the Doppler beaming effect across different bands ($\delta_i^{q_i}/\delta_j^{q_j}$). However, $\delta_i/\delta_j$ plays a pivotal role in the distribution, while jet shape ($q=2(3)+\alpha_\nu$) and spectral indices ($\alpha_\nu$) play a minor role. Our results suggest that FSRQs+LBLs are strong-jet sources coupled with radiatively efficient accretion, and their jets are accelerated to a larger distance from the core and still maintain relativistic speeds down to the radio region; HBLs are weak-jet sources coupled with radiatively inefficient accretion, and their jets may begin to decelerate in the optical region and exhibit sub-relativistic speeds as they propagate to the radio region. IBLs are regarded as transitional objects between FSRQs+LBLs and HBLs.
Read the full abstract

High Energy Physics (Phenomenology)

CGC-py: A Monte Carlo Event Generator for Gluon Saturation Physics

We develop CGC-py, a Monte Carlo event generator for deep-inelastic scattering. It couples the full Color Glass Condensate (CGC) cross section for $\gamma^*p(A)\to q\bar q+X$ to a Parton-Branching transverse-momentum-dependent backward initial-state shower, while Pythia~8 handles final-state radiation and hadronization. CGC-py retains the complete target-elastic and target-inelastic contributions without taking the back-to-back correlation limit, allowing single- and di-hadron observables to be generated consistently from the same event sample. We validate the generator through an analytic closure test of the single-inclusive quark spectrum and a comparison of charged-hadron spectra in $ep$ collisions with H1 data, finding excellent agreement. The predicted nuclear modification factor $R_{e\mathrm{Au}}^h$ shows the expected saturation pattern: suppression at low $p_T^*$ followed by a rise toward unity at higher $p_T^*$. A comparison with a Pythia~6 baseline, together with an $x_g$-rescaling study, indicates that small-$x$ CGC evolution and collinear DGLAP dynamics contribute comparably to the growth of the dihadron away-side width with energy. Genuine saturation-driven broadening emerges only at the highest energies considered. Within CGC-py, $e\mathrm{Au}$ collisions exhibit an enhanced away-side width and a suppressed back-to-back yield relative to $ep$ collisions. These nuclear effects remain modest over EIC kinematics, motivating measurements at the most forward accessible kinematics and the use of complementary observables to maximize sensitivity to gluon saturation.
Read the full abstract

All authors Haowu Duan, Cong Yi, Si-Wei Dai, Shu-Yi Wei, Wenbin Zhao, Liang Zheng

Quantum Gases

Universal scaling of fluctuations and correlations across the superfluid transition

The critical behavior of a system near a continuous phase transition is commonly characterized by power laws and a set of universal critical exponents. Yet universality at phase transitions has even more fundamental manifestations. It dictates that all observables follow universal scaling functions, which may extend beyond simple power laws. Furthermore, microscopic details are captured entirely by only two system-specific scale factors, that rescale any measured quantity onto its universal form. In this work, we report the experimental validation of this prediction in ultracold lattice Bose gases undergoing the superfluid transition. We extract the scale factors by collapsing the order-parameter cumulants measured at varying entropies. We show that these factors specify scaling functions governing both the order-parameter distribution and two-point correlations. By measuring these scaling functions, we also determine three critical exponents $\beta$, $\gamma$ and $\nu$. Our results provide an experimental demonstration that universal scaling is simultaneously obeyed by multiple observables in a quantum many-body system.
Read the full abstract

All authors Paul Paquiez, Géraud Dupuy, Maxime Allemand, Henri Coquinot, Tommaso Roscilde, Nicolas Dupuis, Adam Rançon, Thomas Chalopin, David Clément

Astrophysics of Galaxies

Constraints on mu-variations from the methanol CH3OH thermal lines in the Galaxy at galactocentric distances of 1.5 < D_GC < 13 kpc

In this study, constraints are set on hypothetical variations of the fundamental physical constant mu = m_e/m_p - the electron-to-proton mass ratio - based on thermal emission lines of E-methanol (CH3OH) in the 216-220 GHz frequency range. Molecular spectra toward seven massive clouds located across a wide range of galactocentric distances (1.5 < D_GC < 13 kpc) have been analyzed. The obtained weighted mean value <Delta mu/mu> = (0.5+/-0.5)*10^(-7) does not indicate statistically significant changes in mu at the 1 sigma confidence level of 5*10^(-8), which is in good agreement with previously established upper limits in a number of molecular clouds in the Galactic disk.
Read the full abstract

Quantum Physics

Tunable topological enhancement of covariant quantum Fisher information via non-Bloch skin effect in non-Hermitian SSH lattices

The covariant quantum Fisher information (CQFI) has recently been established as the ultimate precision benchmark for pseudo-Hermitian sensors [Phys. Rev. Lett. 136, 080802 (2026)], yet existing analyses are limited to single-mode systems. Here we extend the CQFI formalism to multi-mode non-Hermitian Su-Schrieffer-Heeger lattices and reveal tunable topological enhancement enabled by the non-Hermitian skin effect (NHSE). Under open boundary conditions, the NHSE deforms the conventional Brillouin zone into a generalized Brillouin zone of radius r = exp(ąppa}), where ąppa} denotes the non-Bloch decay rate. While the total CQFI scales linearly with system size N, its prefactor depends critically on ąppa}, yielding an enhancement factor E(N) = F_OBC / F_PBC that exceeds 30 for N ~ 30, substantially outperforming periodic-boundary sensors. The enhancement is robust against moderate local disorder and supports multi-parameter estimation, with the joint Cramér-Rao bound reduced by up to 15 orders of magnitude. These findings establish a spatial-domain mechanism for quantum metrology that complements time-domain strategies and is experimentally accessible using topoelectrical circuits, photonic lattices, and superconducting circuits with current technology.
Read the full abstract

All authors Qi-Cheng Wu, Yan-Hui Zhou, Tong Liu, Dong-Xu Chen, Chui-Ping Yang

Quantum Physics

In defence of the Ehrenfest mean-field molecular dynamics

Re-visiting the problem of the coupled electronic–nuclear motion, we prove that the so called `mean-field' Ehrenfest picture is an exact theory, rather than an approximation, in the classical limit for nuclei. By establishing its full equivalence to the much more involved Exact Factorization approach to the problem (Abedi et al., Europhys. Lett. 106, 33001 (2014)), our conclusion rehabilitates the mean-field Ehrenfest molecular dynamics as a simple, effective, while formally exact scheme, amenable to the use within the framework of the time-dependent density functional theory.
Read the full abstract

Instrumentation and Methods for Astrophysics

Reconstruction of Shower-like Events in NEON Using Likelihood and Graph Neural Network Methods

The Neutrino Observatory in the Nanhai (NEON) is a proposed deep-sea neutrino telescope deployed in the South China Sea. Accurate reconstruction of shower-like events is crucial for neutrino energy measurements and multi-messenger astronomy, yet it poses significant challenges due to seawater optical attenuation, irregular detector geometry, and substantial $^{40}\mathrm{K}$ ambient background. In this work, we present the first comprehensive reconstruction framework for shower-like events in NEON, encompassing both a physics-driven maximum likelihood estimation (MLE) method and a data-driven Graph Neural Network (GNN). The traditional MLE framework integrates spatial-isochronic hit selection, vertex reconstruction via time-residual M-estimator minimization, and decoupled directional and energy estimation based on pre-computed photon distribution tables. Physical calibrations, including PMT angular acceptance, hit-level time slewing corrections, and an effective line-source shower extension, are incorporated into the likelihood formulation. In parallel, a two-stage GNN is developed to capture intra-DOM PMT correlations and distance-weighted inter-DOM topological patterns. Simulation studies show that the MLE method achieves an overall median angular resolution of $4.19^\circ$ and an energy resolution of 25%-37% over 1 TeV to 1 PeV with negligible systematic bias. The GNN further improves reconstruction fidelity in the low-to-intermediate energy regime, achieving a median angular resolution of $1.8^\circ$ at 30 TeV and an energy resolution of $\sim$ 20% between 40 and 300 TeV. Based on these reconstruction performances, the effective area and point-source discovery potential of NEON are evaluated. This framework establishes an essential reconstruction benchmark for NEON and provides practical methodologies for future next-generation deep-sea neutrino telescopes.
Read the full abstract

All authors Sujie Lin, Weiqin Huang, Yihan Liu, Chengyu Shao, Lili Yang, Huiming Zhang

Quantum Physics

An interpretation-independent formulation of the measurement problem

In this paper, we do not try to solve the measurement problem, but rather to properly formulate it. One of the reasons why it still lacks a precise, agreed definition is that the problem may take very different aspects depending on the interpretation of quantum mechanics embraced. Inspired by the methodology of theory-independent results like Bell's theorem, we propose to identify the common root of the puzzle in an interpretation-independent way i.e. as a property of the empirical statistics only, before deriving its philosophical consequences. The key observation is that quantum matter can not be described by a Kolmogorovian probabilistic theory. Arguing that the Kolmogorov axioms of probability theory are the postulates of epistemic uncertainty leads us to reformulate the measurement problem as the impossibility to build an ontology independent of epistemology for quantum matter. Said differently, there exists no God's-eye view on quantum systems. Although it is meaningless to solve the measurement problem as defined in this way, insofar as it is a feature of the universe's statistics, such a formulation may on the other hand bring side benefits. In particular, we argue that it allows to: (i) shed a new light on the variety of interpretations; (ii) propose a fundamental reason why quantum mechanics and general relativity are so incompatible, not relying on purely mathematical or technical arguments; (iii) guide the quest for quantum gravity.
Read the full abstract

Astrophysics of Galaxies

Search for intranight optical variability in a large sample of intermediate-mass black holes

Using the extensive archival database of the Zwicky Transient Facility (ZTF) survey, we have investigated intranight optical variability (INOV) in a large sample of low-mass active galactic nuclei (LMAGN) powered by intermediate-mass black holes (IMBHs). After applying a sequence of well-motivated selection filters, we constructed an unbiased, representative sample of 62 IMBHs for which $r$-band intranight photometric sequences are available in the ZTF database, yielding 167 sessions with a minimum duration of 2 h. By performing aperture photometry on the sequence of exposures in each session, we derived differential light curves (DLCs) of the target LMAGN relative to two carefully selected non-varying comparison stars monitored simultaneously with the LMAGN in the same exposure sequence. Application of the widely used test based on $F$-statistics to all these DLCs revealed no case of statistically significant INOV. We discuss this result for the present large sample of LMAGN in the context of an earlier report of INOV detections in another, albeit much smaller and differently selected, sample of LMAGN that had been monitored in targeted observations.
Read the full abstract

All authors Himanshu Sharma, Gopal-Krishna, Vibhore Negi, Hum Chand, Krishan Chand, Anshul Kumar Sharma

High Energy Physics (Phenomenology)

Exploring millicharged particles in laboratory and astrophysical strong-field regimes

The probe of light dark particles beyond the Standard Model (SM) under a strong-field environment has drawn significant attention. In this work, we investigate the potential to search for and constrain light millicharged particles (MCPs) via strong electromagnetic fields in both laboratory laser experiments and astrophysical environments such as magnetars. We propose the MCP pair production from nonlinear Compton scattering through the interaction of a relativistic electron beam with a high-intensity laser pulse. The Furry picture and Volkov solution of Dirac equation in a background electromagnetic field are used to describe the electrons and MCPs under an external classical laser field. We calculate the cross sections of nonlinear Compton scattering to MCP pairs and take into account the irreducible SM background with missing neutrinos. We also revisit the MCP pair production via the Schwinger mechanism from magnetars with ultra-strong magnetic field and parallel electric field in polar gap. The energy loss due to the Schwinger pair production of MCPs and electric field acceleration is evaluated based on Ruderman-Sutherland model for confirmed magnetars. We find that the constraints from highly magnetized magnetars and the search potential in laboratory laser experiments are complementary.
Read the full abstract

All authors Cheng-Rui Jiang, Tong Li, Kai Ma, Haolong Wang

Fluid Dynamics

Interface-resolved simulations of boiling heat transfer

Boiling heat transfer underpins many applications where large heat fluxes must be dissipated. Boiling is characterized by a wide range of coupled multiscale transport phenomena, making its accurate numerical prediction a long-standing challenge. In this context, interface-resolved simulation approaches - where the liquid-vapor interface is either explicitly or implicitly described - have undergone significant advancements, driven by improved numerical formulations, more complete thermodynamic and compressibility modeling, and the growing availability of computational resources. Here, we provide a comprehensive overview of the state of the art in interface-resolved simulations of boiling flows. We examine the different formulations governing the flow and temperature field, strategies for coupling heat and mass transfer at the interface, and current modeling approaches for small-scale physics such as nucleation, microlayer evaporation, and contact-line dynamics. By analyzing insights from recent high-fidelity simulations, a central observation is that interface-resolved simulations of boiling are hydrodynamically resolved but microscopically modeled: their predictive accuracy depends on the sub-grid closures for nucleation, microlayer, and contact-line physics no less than on the fidelity of the hydrodynamic solver. We discuss the strengths and limitations of available methods on this basis, together with the open challenges in the accurate description of boiling heat transfer.
Read the full abstract

General Relativity and Quantum Cosmology

Solutions for neutron stars in General Relativity from a complexity structure scalar boundary condition

A new condition involving the complexity factor, a structure scalar arising from the orthogonal splitting of the Riemann tensor, is generated at the boundary of a spherically symmetric anisotropic fluid. This condition leads to the generation of a model, without invoking any further constraints on geometry or matter variables. The model generated is physically reasonable and suggests that there is a non-zero, positive minimum constraint on the complexity scalar value evaluated at the surface. This suggests that vanishing complexity is a globalized constraint which does not apply at the boundary, specifically for compact objects in the strong-gravity regime.
Read the full abstract

All authors Robert S. Bogadi, Megandhren Govender, Genly Leon, Andronikos Paliathanasis