Nuclear Theory
Quark matter at finite temperature and proto-quark stars with the axion effects in SU(3) Nambu-Jona-Lasinio model
Peng-Cheng Chu, Jiao-Jiao Wang, Ke Liu et al. (+8 more)
We investigate the thermodynamical properties of strange
quark matter (SQM) and proto-
quark stars (PQSs) within the SU(3) Nambu-Jona-Lasinio (NJL) model at finite temperature, specifically incorporating the effects of
axion fields and vector interactions. Our results demonstrate that these interactions significantly influence the equation of state (EoS), constituent
quark masses,
entropy density, and the maximum
star mass of PQSs at the isentropic stages along the
star evolution line. Furthermore, we reveal a distinct thermodynamic signature in the early
evolution: the presence of trapped
neutrinos leads to a substantial increase in electron number density while simultaneously suppressing the core temperature compared to the
neutrino-free case. These findings may highlight the crucial role of the
axion effects,
flavor-dependent vector interactions, and particle composition in determining the observable properties of compact
stars at finite temperature.
Read the full abstract ▾
All authors Peng-Cheng Chu, Jiao-Jiao Wang, Ke Liu, Peng Wu, Yu-Heng Liu, He Liu, Hong-Ming Liu, Xiao-Hua Li, Min Ju, Xu-Hao Wu, Ying Zhou
High Energy Astrophysical Phenomena
The impact of nuclear equations of state on the dynamics and multi-messenger emission of magnetorotational stellar explosions
Andrea Celati, Matteo Bugli, Luca Del Zanna et al. (+2 more)
The gravitational collapse of massive
stars at the end of their life leads to powerful
supernova explosions that produce compact objects, regulate the dynamics of host
galaxies, and contribute to
cosmic chemical
evolution. In the presence of fast rotation and strong
magnetic fields, such explosions can reach extreme energies, explaining sources such as hypernovae and long gamma-ray bursts. We investigate the impact of variations in the
nuclear equation of state (EoS) on magnetorotational explosions and their multimessenger emission, including
neutrinos and gravitational waves. Differences in stiffness, composition, and finite-temperature behavior of the EoS affect the collapse, bounce, and jet-launching phases. Using the Aenus-Alcar code, which includes relativistic magnetohydrodynamics, two-moment
neutrino transport,
neutrino-matter interactions, and general-relativistic corrections, we perform axisymmetric simulations with different EoSs. All models start from the same pre-
supernova progenitor with
solar metallicity, a zero-age main sequence mass of 20
solar masses, a dipolar
magnetic field, and a shellular rotation profile. The different EoSs produce significant variations in explosion dynamics, proto-
neutron star properties, ejecta mass, and multimessenger signals. Our results show that magnetorotational core-collapse
supernova signatures depend not only on the cold stiffness of the EoS, but also on its thermal and compositional properties, highlighting the importance of combining gravitational-wave and
neutrino observations to constrain dense matter physics and the explosion mechanism.
Read the full abstract ▾
All authors Andrea Celati, Matteo Bugli, Luca Del Zanna, Marco Cusinato, Martin Obergaulinger
High Energy Physics (Theory)
Scalar Hair at the String-Black-Hole Correspondence
Eliseo Pavone
We study static, spherically symmetric
axion–dilaton solutions of the tree-level four-dimensional string effective action. Using the sigma-model structure of the scalar sector, we show that the full family of static, spherically symmetric and asymptotically flat solutions is obtained as the $SL(2,\mathbb R)$ orbit of the pure-dilaton FJNW solution, and we characterize the associated
axion–dilaton charge space. We then analyze the perturbative regime of these solutions by comparing the onset of $\alpha'$
curvature corrections with that of string-loop corrections. Finally, we apply the string–black-hole correspondence criterion to the FJNW family by evaluating the local $\alpha'$
curvature diagnostic at the physical size $R_{\rm typ}$ of a highly excited string state. With the normalization fixed on the Schwarzschild branch, Schwarzschild saturates the nominal $\alpha'$ threshold at the correspondence surface, whereas every scalar-haired FJNW branch lies above it. More generally, independently of the common overall normalization within the matching prescription, every nonzero-hair branch has a larger
curvature diagnostic at the correspondence surface than Schwarzschild. Away from the correspondence point, scalar-haired exteriors may remain under $\alpha'$ control at sufficiently weak local self-
gravity and may provide perturbatively controlled long-distance fields of highly excited string states whenever the local string coupling also remains weak.
Read the full abstract ▾
Optics
Twist-angle Control of Nonlinear Interference in a ZnO Nanowire/Monolayer WSe$_2$ Hybrid Structure
Maximilian Tomoscheit, Benedikt Mathes, Alexander Zaunick et al. (+6 more)
Nanoscale devices that integrate materials of different dimensionalities (0D, 1D, and 2D) hold great potential for advanced applications in photonics and optoelectronics. A fundamental requirement for the development of such devices is the engineering and control of light-matter interactions beyond the simple enhancement or quenching of linear and nonlinear optical emission. In this study, we demonstrate control over nanoscale light-matter interactions by achieving twist-angle tunability of the nonlinear optical response in a hybrid system composed of a ZnO nanowire and a monolayer of WSe$_2$. By varying the relative orientation between the ZnO polar axis and the WSe$_2$
crystal axes, we realize both constructive and destructive interference in second-harmonic generation, as well as full material selectivity in second harmonic polarization-dependent measurements. These outcomes arise from the distinct dimensionalities and
symmetries of the hybrid constituents, underscoring the generality of our approach. Thus, our work presents an advanced framework for the design and control of nonlinear light-matter interactions in nanoscale hybrid devices, thereby paving the way for their future use in photonic and optoelectronic technologies.
Read the full abstract ▾
All authors Maximilian Tomoscheit, Benedikt Mathes, Alexander Zaunick, Moritz Willems, Edwin Eobaldt, Priyanka S. Prakash, Eva Perlt, Carsten Ronning, Giancarlo Soavi
Statistical Mechanics
Viktor Eisler and Erik Tonni
We study the
entanglement Hamiltonian of an infinite hopping chain in its ground state, after partial projective measurements in the occupation basis. For a segment separated by two measurement regions from the rest of the chain, we show that the reduced density
matrix can be related to a grand-canonical state via a conformal mapping and a gauge transformation in the underlying field-theory description. The
entanglement Hamiltonian is then described by a local inverse temperature that vanishes as a square root around the endpoints and is independent of the particular measurement outcome. In sharp contrast, the local chemical potential is shown to be related to the induced charge density in the segment. Hence the
entanglement Hamiltonian of a post-selected state contains much more information on the measurement outcome than the respective
entropy.
Read the full abstract ▾
Solar and Stellar Astrophysics
Kilogauss magnetic fields from simulations of small-scale dynamo action in the convective envelope of a white dwarf
Fabio Riva, Tim Cunningham, Hans-Günter Ludwig et al. (+2 more)
About 20% of white
dwarfs are observed to host large-scale
magnetic fields, but the origin of white
dwarf magnetism remains uncertain. Small-scale turbulent dynamos (SSDs), which efficiently generate
magnetic fields in
solar and
stellar convection simulations, have so far been studied in white
dwarfs only through equipartition arguments in one-dimensional models. We therefore investigate whether turbulent convection in white
dwarf surface layers can sustain SSD action through local three-dimensional radiation-magnetohydrodynamics simulations of a DA white
dwarf with a convective pure-hydrogen atmosphere, including the full convection zone together with the underlying overshoot and stably stratified layers. Starting from a weak seed field of 1 mG, the
magnetic energy undergoes exponential amplification before saturating at a
magnetic-to-kinetic energy density ratio of about 5.5% at the visible surface, demonstrating that SSD action naturally generates kG-strength
magnetic fields in convective white
dwarf atmospheres. The resulting
magnetic field is characterised by a mixed-polarity small-scale structure, with kG field concentrations contributing about 14% of the total unsigned
magnetic flux at the visible surface. Despite a rate of
magnetic energy generation amounting to roughly one-seventh of the bolometric flux, no significant modification of the mean stratification is found. Although these fields remain spatially unresolved for observations, they may contribute to spectral line broadening, suggesting that small-scale magnetism in white
dwarfs could be more widespread than currently inferred from observations.
Read the full abstract ▾
All authors Fabio Riva, Tim Cunningham, Hans-Günter Ludwig, Oskar Steiner, Pier-Emmanuel Tremblay
Astrophysics of Galaxies
Luminosity function of quasars at $1.0<z<3.5$ from SDSS and DESI
Gaocheng Yin, Linhua Jiang, Zhiwei Pan et al. (+54 more)
We present a study of the
evolution of type 1
quasars at $1.0<z<3.5$, covering the peak epoch of
quasar activity. The
quasar evolution has been extensively explored by a variety of previous works and the derived
quasar luminosity functions (QLFs) are not well consistent with each other, presumably due to the complexities introduced by different
quasar selection techniques and associated completeness corrections. We use a new strategy to construct QLFs based on a library of all known
quasars. We focus on a wide region of $\sim$1700 deg$^2$ and a deep field of $\sim$265 deg$^2$ that have rich spectroscopic data primarily from SDSS and DESI. We then apply traditional color cuts in the rest-frame UV/optical to select
quasar candidates and use the
quasar library to identify them. Our final sample consists of 62,426
quasars at $1.0<z<3.5$, with a high completeness ($\sim$96%) and a high purity ($\sim$93%) in the color selection. Simple color cuts can potentially minimize selection biases for the study of
quasar evolution. We derive binned QLFs and characterize them using a double power-law model. Sample incompleteness and contamination are considered as part of the uncertainties in the calculation. Compared to previous results, our QLFs are slightly higher at the faint end, and also higher at the bright end at $2.5<z<3.5$. The QLFs suggest that the
quasar evolution at $1.0 < z < 2.5$ can be well described by the pure luminosity
evolution model, while at $2.5 < z < 3.5$, it can be described by either the pure luminosity
evolution or the pure density
evolution model.
Read the full abstract ▾
All authors Gaocheng Yin, Linhua Jiang, Zhiwei Pan, Paul Martini, Wei-Jian Guo, Siwei Zou, Shengxiu Sun, Swayamtrupta Panda, Abhijeet Anand, Benjamin Alan Weaver, Aaron Meisner, Andrei Cuceu, Arjun Dey, Axel de la Macorra, Christophe Magneville, David Brooks, David Kirkby, David Schlegel, David Sprayberry, Davide Bianchi, Dick Joyce, Enrique Gaztañaga, Eusebio Sanchez, Francisco Javier Castander, Francisco Prada, Gaston Gutierrez, Graziano Rossi, Gregory Tarlé, Hiram K. Herrera-Alcantar, Hu Zou, Ignasi Pérez-Ràfols, Jaime E. Forero-Romero, Jessica Nicole Aguilar, John Moustakas, Joseph Harry Silber, Klaus Honscheid, Laurent Le Guillou, Marc Manera, Martin Landriau, Michael Schubnell, Mustapha Ishak, Nathalie Palanque-Delabrouille, Peter Doel, Ramon Miquel, Robert Kehoe, Satya Gontcho A Gontcho, Seshadri Nadathur, Simone Ferraro, Stephanie Juneau, Steven Ahlen, Theodore Kisner, Todd Claybaugh, Will Percival, Anthony Kremin, Claire Lamman, Claire Poppett, Rongpu Zhou
Mathematical Physics
Triviality in a Non-Perturbative Second-Order Mean-Field Theory for $\phi^4_4$
Majdouline Borji
We introduce a second-order mean-field description of the four-dimensional Euclidean $\phi^4$ model within the Wilson–Polchinski renormalization-group framework. The construction is based on the connected amputated Schwinger functions evaluated at the symmetric momentum configurations $ (p,-p,\ldots,p,-p)$, which are decomposed into a momentum-independent component, a component quadratic in $p$, and a higher-order remainder. The first two components are chosen to satisfy a closed nonlinear hierarchy. We prove the existence of solutions to this hierarchy for arbitrary positive bare coupling and establish their convergence to the Gaussian fixed point as the ultraviolet cutoff is removed. In particular, both the momentum-independent and the quadratic momentum sectors are asymptotically trivial.
Read the full abstract ▾
Fluid Dynamics · Cross-listed from math.AP
Prandtl–Batchelor and flux-expulsion selection for steady MHD flows in a disk
Chen Gao, Zhiwu Lin and Jianfeng Zhao
We study the simultaneous vanishing-viscosity and vanishing-resistivity limit of steady incompressible MHD flows in a disk. The boundary velocity is a small nonaxisymmetric perturbation of a rigid rotation with mean angular speed \(\alpha\), while the prescribed tangential
magnetic trace has mean \(\beta\). Assuming \(\alpha\neq0\) and the non-Alfvénic condition \(|\alpha|\neq|\beta|\), we construct solutions converging on compact interior subdisks to a rigidly rotating ideal MHD core with constant vorticity and out-of-plane current density. A new MHD–Wood law determines the two core rotations from the boundary data: the velocity core is selected by a coupled kinetic–
magnetic balance, whereas the
magnetic core is fixed by the imposed mean circulation. Consequently, zero circulation gives complete interior
magnetic expulsion, while nonzero circulation leaves a uniform
magnetic rotation after the nonaxisymmetric modes are confined to a thin boundary layer. This provides a fully coupled realization of Prandtl–Batchelor selection and flux expulsion; unlike classical kinematic models, the
magnetic field actively changes the flow and need not be weak. The proof combines a non-Alfvénic coercive theory for a periodic MHD boundary layer, global matching of the two fields, and a coupled stability estimate adapted to the
magnetic boundary condition. A separate conditional
rigidity argument, using exact viscous identities and local convergence but no interior asymptotic expansion, explains the same core structure for a broader single-eddy family.
Read the full abstract ▾
Quantum Physics
Towards fault-tolerance with universal phase-error-transparent gates for high-spin cat codes
Kelvin Onggadinata, Si Yan Koh, Arghya Maity et al. (+5 more)
High-dimensional
nuclear spins offer a hardware-efficient route to
quantum error correction (QEC), with the
spin cat code providing intrinsic robustness against phase errors – the dominant noise channel in donor-in-silicon architectures. However, realizing the full potential of this encoding requires gate operations that preserve its error-correcting properties. In this work, we construct a universal logical gate set that is error-transparent (ET) to phase errors, and discuss its practical implementations and challenges. The ET gates ensure that phase errors occurring stochastically during gate operations are propagated in a systematically traceable manner and remain correctable in a subsequent QEC step. Among the universal gate set constructed, we identify the logical $X$ gate as the primary challenge and discuss potential realization schemes. In addition, to fully leverage the
spin cat code's advantage over an unencoded
qubit, multi-tone microwave driving of the logical $CZ$ gate is essential. Our simulations show that ET gates significantly outperform non-ET gates and may be necessary to surpass the break-even point. We further show how logical measurement and recovery can be constructed from ET operations, and explain why state-preparation cannot be made ET. In particular, ET measurement in the computational basis is realizable via
spin parity measurement, and that error correction
circuits constructed from ET operations achieve optimal error correction capacity. Our work charts a concrete path toward full fault-tolerant
quantum computation with high-dimensional
nuclear spin systems.
Read the full abstract ▾
All authors Kelvin Onggadinata, Si Yan Koh, Arghya Maity, Kuan Eng Johnson Goh, Bent Weber, Kay Jin Lim, Hui Khoon Ng, Teck Seng Koh
Applied Physics · Cross-listed from cs.AI
OPERA: Operator-residual feedback for reliable autonomous optical experiments with language-model agents
Ning Xu, Xiang Zheng, Fuqiang Zhong et al. (+4 more)
Autonomous
agents choose actions using scores that may not reflect experimental success. We developed OPERA, an operator-residual framework for optical experiments. It represents experimental actions as optical operators and evaluates their outcomes using physically interpretable residuals. Operators specify executable changes to measurement, control or reconstruction, while residuals report departures from specified physical conditions. The
agent uses both to select, combine or generate operators, and physical performance is evaluated independently against a withheld reference. Across three optical tasks, score-only feedback produced score increases without physical improvement in 23.6–39.0% of decisions, compared with 0.9–1.9% for operator-residual feedback. Operator-residual feedback increased the probability of reaching and maintaining task targets and reduced experimental budgets. Protocols selected in digital twins were transferred to three optical instruments, and repeated experiments showed a lower projection budget in structured-light reconstruction. Together, operators and residuals guide autonomous decisions using measurable physical evidence.
Read the full abstract ▾
All authors Ning Xu, Xiang Zheng, Fuqiang Zhong, Huadong Wang, Xiaolong Wu, Zhiyuan Liu, Hui Ning
Strongly Correlated Electrons
Resilient strange metal at an unconventional quantum critical point in $d=2$
Jérôme Leblanc and A.-M. S. Tremblay
Properties of the two-dimensional Hubbard model with nearest-neighbor hopping are under scrutiny in cold-atom experiments and diagrammatic
quantum Monte Carlo. Given the controlled nature of these approaches, it is timely to make predictions about strange-metal behavior and its relation to
quantum-critical properties. Even for interaction strengths below the Mott transition, several peculiarities occur at the
quantum critical point separating
Fermi liquid and incommensurate
spin-density wave order. Here, we predict, using the non-perturbative improved two-particle self-consistent approach, that for correlation lengths ranging from about one to one hundred
lattice spacings, Kohn anomalies on the underlying
Fermi surface lead to unconventional critical exponents. The temperature dependence of the single-particle self-energy acquires strong momentum dependence along the
Fermi surface with no clear evidence of Landau quasiparticles. Nevertheless, we observe strange-metal behavior, namely, resistivity that scales linearly with temperature as $T\rightarrow{0}$. Our work shows that a linear temperature dependence of resistivity arises without a linear-in-temperature self-energy along the
Fermi surface, as is often assumed.
Read the full abstract ▾
Solar and Stellar Astrophysics
Thermal Non-equilibrium Cycles in a Non-eruptive Pseudo-Streamer
Clara Froment and Sophie Masson
Thermal non-
equilibrium (TNE) is a well-known thermodynamic mechanism, generally studied in coronal loops. These evaporation and condensation cycles are induced by a quasi-steady and stratified heating. Long-period EUV pulsations and coronal rain are two manifestations of TNE. The quasi-periodicity of the cycles is a strong characteristic of TNE as the system dynamically evolves around an
equilibrium position that is not reachable. There are recent reports of coronal rain at open-closed boundaries such as fan-spine
topologies and pseudo-streamers. However, no definite conclusions were drawn on the physical mechanisms driving these coronal rain events. We report the detection of long-period EUV pulsations and co-spatial recurring coronal rain showers in a pseudo-streamer observed with AIA on board SDO. The
magnetic topology and
evolution of the pseudo-streamer are studied in detail using a combination of PFSS modeling and EUV dynamics. The 2.5-day event exhibits all the characteristic features of previous TNE events reported in coronal loops: periodic EUV pulses appearing sequentially in the different channels, following the ordering of the peaks in their temperature response, and coronal rain showers appearing toward the end of these cycles. We further show that the TNE cycles in the pseudo-streamer occur not only in the closed field but also in the open field. Our observations support the findings of recent numerical studies showing that TNE can also occur in open field regions and at open-closed boundaries. In parallel, interchange reconnection occurs continuously and non-impulsively all along the open-closed boundary as seen in EUV. The interplay between TNE and interchange reconnection should be studied in detail in future works. This observation opens further perspectives for the understanding of TNE in the
solar atmosphere and its potential implications for the
solar wind.
Read the full abstract ▾
Strongly Correlated Electrons
Dissipation-induced bulk and boundary criticality in the Haldane chain
Zhenjiu Wang and Manuel Weber
We study the Haldane chain coupled to a dissipative ohmic bath. Using large-scale
quantum Monte Carlo simulations, we identify a second-order
quantum phase transition into an
antiferromagnetic state with spontaneously broken SO(3)
symmetry that is governed by an interacting fixed point with dynamical exponent $z\approx 2$. We derive a generalized string order parameter which indicates that the
symmetry-protected topological ground state of the Haldane chain is stable for weak dissipation and develops a nontrivial scaling dimension at criticality. In particular, its topological edge modes display nontrivial boundary criticality that is distinct from an equivalent transition out of a trivial state; for the latter, we perform an accurate $\epsilon$ expansion of a dissipative $\phi^4$ theory with ordinary boundary conditions. Our setup realizes a
spin impurity in a critical yet nonconformal antiferromagnet and paves the way for continuously tunable boundary criticality controlled by dissipation.
Read the full abstract ▾
Solar and Stellar Astrophysics
Chromospheric Dynamics of an Umbral Flare Kernel - Based on Coordinated SUNRISE III SCIP and Domeless Solar Telescope Observations
Ayumi Asai, Satoru UeNo, Takuma Matsumoto et al. (+34 more)
We report imaging spectroscopic observations of an M1.4
solar flare obtained during a coordinated observation between the infrared spectropolarimeter SCIP onboard the SUNRISE-III balloon mission and Domeless
Solar Telescope (DST) at Hida Observatory, Kyoto University. The
flare that occurred on 2024 July 13 in NOAA Active Region 13738 exhibited a compact
flare kernel located within a sunspot umbra. SCIP performed rapid slit-scan observations over a field of view of 58" x 58" around the umbra with a cadence of 40 s, covering infrared chromospheric and upper-photospheric lines including Ca II 8498/8542 A and K I D1. At the same time, DST observed a wider surrounding region with a cadence of 25 s in H-alpha, Ca II 8542 A, and Na I D1/D2. Clear
flare-related brightenings are detected in all chromospheric lines observed by SCIP and DST, while no significant enhancement is found in photospheric lines. The high spatial resolution of SCIP reveals fine substructures within the kernel on spatial scales of order 1000 km, which appear smeared in ground-based observations. The spectral profiles exhibit temporally and spatially varying Doppler shifts and line broadenings, indicating complex, fine-scale
plasma motions in the chromosphere. These results suggest that the observed red asymmetry arises from the temporal succession of multiple fine-scale kernels, as revealed by SCIP, rather than from a single continuous process.
Read the full abstract ▾
All authors Ayumi Asai, Satoru UeNo, Takuma Matsumoto, Takayoshi Oba, Yukio Katsukawa, Masahito Kubo, Ryohtaroh T. Ishikawa, Yusuke Kawabata, Hirohisa Hara, Yoshihiro Naito, Toshifumi Shimizu, Sami K. Solanki, Andreas Lagg, Achim Gandorfer, Jose Carlos del Toro Iniesta, Pietro Bernasconi, Thomas Berkefeld, Alex Feller, Tino L. Riethmuller, Alberto Alvarez-Herrero, H. N. Smitha, David Orozco Suarez, Bianca Grauf, Michael Carpenter, Alexander Bell, Valentin Martinez Pillet, Laurent Gizon, Francisco Javier Bailen, Julian Blanco Rodriguez, Juan Sebastian Castellanos Duran, Edvarda Harnes, Johannes Hoelken, Francisco A. Iglesias, Azaymi L. Siu-Tapia, Hanna Strecker, Dusan Vukadinovic, SUNRISE-III team
General Relativity and Quantum Cosmology
Coherent End-to-End Search for Generic Extreme-Mass-Ratio Inspirals
Xiaobo Zou, Xingyu Zhong, Wen-Biao Han et al. (+1 more)
Extreme-mass-ratio inspirals (EMRIs) encode more than $10^5$ strong-field orbital cycles and are key targets for space-borne gravitational-wave interferometers, yet coherent recovery of generic systems over astrophysically broad priors remains unresolved. Successive Mock LISA, LISA, and Taiji Data Challenges (MLDCs, LDCs, and TDCs) have not yet produced a complete, generally reliable solution for blind EMRI detection and parameter recovery across such priors. The central obstacle is a needle-in-a-haystack likelihood: six phase-
evolution parameters span a vast domain, producing an exceptionally narrow global maximum amid numerous secondary maxima. We show that higher-likelihood secondary maxima concentrate progressively around the global maximum and can therefore guide an adaptive contraction of the search volume. We exploit this structure through a reduced-dimensional profile likelihood and a coherent hierarchical strategy to search for EMRI signals across the full 14-dimensional parameter space. This enables the first end-to-end coherent parameter estimation for generic EMRIs with astrophysically broad priors. In stationary Gaussian LISA noise, the search recovers two half-year analytical-kludge signals with signal-to-noise ratios near 50, yielding fitting factors of 0.989 and 0.971, fractional errors of $10^{-3}$–$10^{-2}$ in the phase-
evolution parameters and near $3\%$ in the distance, and error of less than $0.1$ radian in the sky location. The method turns secondary maxima into guides for a coherent hierarchical search.
Read the full abstract ▾
All authors Xiaobo Zou, Xingyu Zhong, Wen-Biao Han, Soumya D. Mohanty
High Energy Physics (Theory)
Three-Loop Five-Point CK-Dual Amplitudes and UV Structure in N=4 SYM and N=8 SUGRA
Zhiming Cai, Zeyu Li, Gang Yang et al. (+1 more)
We construct the complete full-color three-loop five-point integrand of N=4 super-Yang–Mills theory in a representation that manifestly satisfies color–kinematics duality. Its double copy gives the corresponding N=8 supergravity integrand. For four-dimensional external states, we evaluate the ultraviolet poles of both amplitudes in the critical dimension, Dc=6. Extending the external-state dependence to D dimensions is subtle. We consider a candidate replacement of the four-dimensional prefactors by expressions built from D-dimensional tree amplitudes. It reproduces the open-string prediction for the SYM pole with generic D-dimensional external states, whereas the corresponding
gravity expression differs from the string-inspired one by an evanescent term.
Read the full abstract ▾
All authors Zhiming Cai, Zeyu Li, Gang Yang, Guorui Zhu
Quantum Physics
Geometry-Only CSL/DP Ratios and the Nonuniqueness of Decoherence Kernels
Randy Davila and Gerard J. Milburn
We study idealized levitated protocols that create spatial superpositions of massive test particles. For each protocol, we compare the dimensionless contrast-loss exponent of mass-proportional continuous spontaneous localization (CSL) with the Diósi–Penrose (DP) self-energy exponent $E_G\tau/\hbar$. We first prove that the point-particle CSL separation kernel has an exact random-
unitary realization: Gaussian momentum kicks arriving at Poisson-distributed times produce the same unconditional decay of spatial coherence, although a pure state conditioned on the complete kick record remains pure. The separation kernel alone therefore specifies an operational decoherence law, not the occurrence of objective collapse. We then show that the ratio of the CSL and DP exponents is independent of particle mass and interrogation time. In the point-particle model it depends only on branch separation and an effective distance; for the standard GRW reference parameters, its resolved-superposition crossover is $x_*\approx1.91\,\mathrm{nm}$. For rigid spherical bodies with an arbitrary normalized radial mass profile, total mass, overall density scale, and interrogation time again cancel, leaving a dimensionless geometry factor. The results distinguish three requirements for a decisive experiment: detectable absolute effects, a controlled comparison of CSL and DP scales, and observables capable of discriminating physically different dynamics that share the same ensemble decoherence kernel.
Read the full abstract ▾
Quantum Physics
Field-Space Entanglement Dynamics Between Tunnel-Coupled Luttinger Liquids
Léonce Dupays, Taufiq Murtadho, Bi Hong Tiang et al. (+2 more)
Entanglement dynamics depend not only on how a
quantum system is partitioned, but critically on how interactions across that partition are structured. For a spatial bipartition of a locally interacting system,
entanglement is generated near the boundary and then propagates into the bulk. By contrast, when two extended
quantum fields are coupled locally along their entire length, the interaction crosses the field-space partition everywhere, and this generates correlations throughout the system. Here, we study the
entanglement dynamics between two gapless one-dimensional
quantum many-body systems described by Luttinger
liquid theory. The systems are initially decoupled and prepared at zero or finite temperature, after which a time-dependent tunneling interaction is activated uniformly along their length. Within a Gaussian approximation, we derive general analytical expressions for the logarithmic negativity, mutual information, and Rényi
entropies under arbitrary coupling protocols. At zero temperature,
entanglement displays an early-time power-law growth whose exponent is fixed solely by the first non-null derivative of the tunneling protocol. Once the coupling saturates, we obtain exact long-time averages of the information-theoretic quantities and characterise how the correlations scale with temperature and the final coupling strength. We also analyse how mutual information and logarithmic negativity approach the adiabatic limit for a very slow protocol with respect to intrinsic system timescale. This work extends the study of
entanglement dynamics in nonequilibrium field theory to field-space partitions and mixed initial states.
Read the full abstract ▾
All authors Léonce Dupays, Taufiq Murtadho, Bi Hong Tiang, Nelly H.Y. Ng, Paola Ruggiero
Earth and Planetary Astrophysics
The SPACE Program II: No discernible spectral features in the transmission spectrum of the sub-Neptune HD 191939 b observed with HST/WFC3
Cyril Gapp, Lorena Acuña-Aguirre, Reza Ashtari et al. (+17 more)
The atmospheres of sub-Neptunes provide a window into their internal structure and history, shedding light on the origin of this common, but enigmatic, class of
exoplanets. However, the physical and chemical processes that shape sub-Neptunes' transmission spectra, in particular cloud and haze formation, are not well understood. To identify possible correlations between transmission spectra and UV irradiation, the SPACE (Sub-neptune Planetary Atmosphere Characterization Experiment) Program observed an array of sub-Neptunes and their host
stars using the Hubble Space
Telescope (HST), measuring the
planets' transmission spectra between $1.1\,\mu$m and $1.7\,\mu$m with the Wide Field Camera 3 (WFC3) and the
stars' UV spectra with the Space
Telescope Imaging Spectrograph (STIS). Here, we present the observations of HD 191939 b carried out as part of the SPACE Program, which reveal no significant spectral features in the transmission spectrum. The data deliver moderate evidence at significance levels between $2.0\,\sigma$ and $3.2\,\sigma$ against a cloud-free atmosphere with
solar metallicity, rendering this scenario unlikely, but still possible. A super-
solar metallicity of HD 191939 b might be consistent with the known trend of increasing atmospheric
metallicity with decreasing
planet mass. Both hydrocarbon haze formation and cloud condensation can be efficient at HD 191939 b's zero-albedo
equilibrium temperature of $(880\pm 20)\,$K, particularly in atmospheres with super-
solar metallicity, possibly additionally muting absorption features.
Read the full abstract ▾
All authors Cyril Gapp, Lorena Acuña-Aguirre, Reza Ashtari, Mario Damiano, Thomas M. Evans-Soma, David J. Wilson, Kevin France, Laura Kreidberg, Drake Deming, Qiushi Chris Tian, Seth Redfield, Ian J.M. Crossfield, K. Angelique Kahle, Tansu Daylan, Kevin Heng, Bertram Bitsch, James S. Jenkins, Keivan G. Stassun, Antonio García Muñoz, Ludmila Carone
Materials Science
ASE2SPRKKR: a unified Python framework integrating the Spin-Polarized Relativistic Korringa-Kohn-Rostoker method into the Atomic Simulation Environment
Ridha Eddhib, Matyáš Novák, Hubert Ebert et al. (+2 more)
The
Spin-Polarized Relativistic Korringa-Kohn-Rostoker (SPR-KKR) is an all-electron ab-initio multiple-scattering code that provides unique capabilities for treating chemical disorder, finite-temperature magnetism, relativistic effects, and spectroscopic properties of various types of solids through its fundamental formulation in terms of the single-particle Green's function rather than eigenstates. We present ASE2SPRKKR, a comprehensive Python interface that integrates SPR-KKR into the Atomic Simulation Environment (ASE), making SPR-KKR more accessible, streamlined, and uniform. Our implementation extends the ASE's Atoms object to handle fractional site occupations for coherent-potential-approximation calculations while maintaining full compatibility with ASE's extensive ecosystem of structure builders, optimizers, and analysis tools. Automated input generation with validation, comprehensive output parsing, and direct MPI support enable seamless integration into high-throughput and multi-method workflows. We demonstrate the interface through representative applications: semi-infinite surface calculations reproducing Rashba-split Au(111) surface states; one-step photoemission modeling capturing
matrix-element effects; exchange-parameter extraction for atomistic
spin dynamics; and X-ray absorption spectroscopy including
magnetic circular dichroism. Beyond these demonstrations, ASE2SPRKKR is designed with transferability as a first-class concern. By grounding its architecture in FAIR principles of Findability, Accessibility, Interoperability, and Reusability, it establishes a replicable blueprint for bringing other specialized Green's function and first-principles codes into the collaborative, reproducible workflows that modern materials discovery requires.
Read the full abstract ▾
All authors Ridha Eddhib, Matyáš Novák, Hubert Ebert, Aki Pulkkinen, Ján Minár
Quantum Physics
Dynamical phase transition in generalized Dicke model with strongly interacting trapped Rydberg ions
Manish Chaudhary, Rejish Nath and Weibin Li
We study dynamical phase transitions in the generalized dissipative Dicke model in an array of trapped Rydberg ions, where their density-density interactions compete with the collective
spin-
phonon coupling,
laser driving and dissipation. This setting offers a versatile approach to study
equilibrium as well as non-
equilibrium many-body phenomena, as parameters, such as the Ising interaction,
laser-ion and
spin-
phonon coupling can be tuned. Through analyzing the mean-field phase diagram, we find a variety of distinct phases and the emergence of a tricritical point that are sensitively dependent of the interaction between Rydberg ions. We then study the
quantum dynamics for a finite system size and characterize parameter dependent dynamics using the
spin average,
entropy, and Loschmidt echo. Distinctive signatures of the dynamical phases, such as slow relaxation and metastability, arise near the phase transition. This analysis predicts rich
quantum dynamics of the finite system that link to the non-
equilibrium mean-field phases. Our study widens the exploration of collective and non-
equilibrium phases in Dicke models, and reveals that the Rydberg ion interaction drastically affects the phase diagram and dynamics.
Read the full abstract ▾
Exactly Solvable and Integrable Systems
Integrable curl-force Hamiltonians: bi-Hamiltonian structure, separability, and periodic orbits
Alexander Felski and Andreas Fring
We investigate
Hamiltonian curl-force systems with indefinite kinetic energy. We first reconsider Berry's
polynomial Hamiltonian curl-force model, whose numerically observed closed trajectories motivated an integrability
conjecture. A Painlevé analysis yields a non-principal resonance spectrum, so that the corresponding Laurent series cannot accommodate the required number of arbitrary constants of the general solution. The model therefore fails the standard Painlevé test. We then introduce a four-parameter curl-force family and identify the parameter locus on which this system is integrable. We construct a second
Hamiltonian, compatible Poisson tensors, separated complex characteristic variables, and a Lax representation. More generally, the separated form yields
polynomial integrable curl-force
Hamiltonians of arbitrary degree. We also show that the same construction admits a higher time-derivative potentialisation whose free limit is the degenerate Pais-Uhlenbeck oscillator. Finally, we analyse zero-curl invariant reductions and
elliptic periodic solutions, and exhibit an isolated periodic orbit outside the integrable regime. This illustrates that closed trajectories alone do not imply Liouville or Painlevé integrability.
Read the full abstract ▾
High Energy Physics (Phenomenology)
Impact of dimension-8 SMEFT operators on baryogenesis via sphaleron decoupling
Kiyoto Ogawa and Masanori Tanaka
We investigate whether a baryogenesis mechanism known as sphalerogenesis can account for the observed
baryon asymmetry of the Universe within the Standard Model effective field theory. In this scenario, the
baryon asymmetry is generated through the $CP$-asymmetric decoupling of electroweak (EW) sphaleron-like transitions. We introduce seven $CP$-violating dimension-8 operators constructed from the
Higgs doublet and the $SU(2)_L$ gauge fields and show that five of them can individually account for the observed
baryon asymmetry with satisfying experimental constraints from
colliders or electron electric dipole moment measurements. We further study their impact in the presence of a $CP$-violating dimension-6 operator. We find that the dimension-8 contributions can be comparable to the dimension-6 contribution when the dimension-8 operators are generated at one loop, demonstrating that loop-order counting can be as important as canonical mass-dimension counting in sphalerogenesis.
Read the full abstract ▾
Solar and Stellar Astrophysics
Why do massive stars form bow shocks? Bulk ISM motion as the main driver of bow shock formation and geometry
J. van den Eijnden and L. Kaper
Bow shocks are one the most commonly observed impact sites of massive
star feedback. Their existence is often taken as evidence of the supersonic motion or even runaway nature of the massive
star. Bow shock geometry is also used to infer the properties of the
stellar wind. However, some bow shocks have been reported around sub-sonic massive
stars or are orientated differently than the
stellar direction of movement, suggesting a substantial influence of the interstellar medium (ISM). In this work, we quantitatively investigate the dominant cause of bow shock formation around massive
stars. Starting from an infrared sample of known bow shocks, we measure the
stellar peculiar velocities and degree of
alignment of the bow shocks. We find that only half ($52\pm2\%$) of the bow shocks is driven by a supersonic
star and that $70\pm2\%$ of bow shocks is substantially misaligned (>30 degrees). Of our sample, only $21\pm2\%$ of systems can be regarded as classical bow shocks, driven by a supersonic
star in the direction of
stellar movement. For the remaining $79\pm2\%$ of systems, the role of bulk ISM movement in creating the shock is equal to or dominant over the
stellar movement. We then introduce a new statistical method to derive the magnitude of the ISM motions required to play this dominant role. We find that ISM motion of the order $10-15$ km s$^{-1}$, oriented randomly within the local standard of rest, suffices to explain the existence and orientations of the bow shocks in our sample. For the subset of systems facing HII regions, we find evidence that
outflows at $>25$ km s$^{-1}$ from those regions drive the nearby shocks. We conclude that ISM motion is the dominant factor in creating massive
star bow shocks and discuss how ignoring these motions can lead to underestimates of the
stellar wind's mass loss rate by more than an order of magnitude.
Read the full abstract ▾
Plasma Physics
Polarization-Conditioned Fourier-enhanced DeepONet for Electric Field Reconstruction from EFISH Measurements
Zhijian Yang, Edwin Setiadi Sugeng, Yaqi Zhang et al. (+2 more)
Electric-field-induced second-harmonic generation (EFISH) is an established
laser diagnostic for quantifying electric fields in
plasmas, yet ensuring field accuracy remains challenging given the coherent, path-integrated nature of the signal. We address this via machine learning, developing a Polarization-Conditioned
Fourier-enhanced Deep Operator Network (PC-FDON) – a unified operator-learning model that reconstructs field profiles from EFISH measurements across both polarizations and various optical parameters. Its architecture incorporates three advances: (i) a
Fourier-enhanced branch providing inductive bias for the Gouy phase shift and wave-vector mismatch; (ii) a polarization-conditioning branch encoding signal polarization via Feature-wise Linear Modulation (FiLM) and gated units, enabling one model to handle both polarizations; and (iii) a physics-informed loss enforcing self-consistency with the governing EFISH equation. Trained on data spanning multiple function families, polarization states, and phase-mismatch values, PC-FDON achieves promising reconstruction under noise-free, incomplete, and noisy inputs, with generalizability comparable to our previous polarization-specific model. Pointwise epistemic uncertainty estimates via Monte Carlo dropout reflect model confidence and enable out-of-distribution (OOD) detection through a location-dependent exceedance fraction metric. Validation is performed on realistic electrode configurations under both polarizations and varying Rayleigh ranges, including a simulated surface dielectric barrier discharge where the framework correctly flags OOD inputs, and experimental data showing good agreement with simulations. The architecture – spectral inductive bias, conditional modulation, and
dataset-specific uncertainty – shows strong potential for broader application beyond
plasma diagnostics.
Read the full abstract ▾
All authors Zhijian Yang, Edwin Setiadi Sugeng, Yaqi Zhang, Anbang Sun, Tat Loon Chng
Statistical Mechanics
Dynamic scaling behavior in the presence of a periodic magnetic driving across Ising continuous transitions
Andrea Pelissetto and Ettore Vicari
We study the critical dynamics arising from a time-dependent periodic homogenous source coupled to the order-parameter field, which drives a classical
ferromagnetic system across a continuous transition. For this purpose, we consider the paradigmatic two-dimensional (2D) Ising model in the presence of a periodic
magnetic field $h(t)=-A\, \cos (2\pi t/P)$, evolving under a purely relaxational dynamics at the critical temperature. We show that the periodic driving gives rise to a peculiar dynamic scaling behavior in the thermodynamic limit, arising from a nontrivial interplay among the time $t$, the amplitude $A$ and period $P$ of $h(t)$. The relevant scaling variables are $\tau=t/P$ and $\sigma=A P^\kappa$, with $\kappa = y_h/z$, where $y_h=(d+2-\eta)/2$ is the critical dimension of the
magnetic field, and $z$ is dynamic exponent for the critical relaxational dynamics ($\kappa\approx 0.865$ for the 2D Ising model). The dynamic scaling behaviors of the magnetization and bond-energy density show an oscillatory behavior around a smooth curve which approaches a large-$\tau$ stationary behavior. We also briefly discuss the dynamic behavior of an Ising system driven across the critical point by a periodic time-varying temperature at zero
magnetic field.
Read the full abstract ▾
Quantum Physics
Exponential Speedup of Entanglement Generation by Quantum Mpemba Effects
Sara M. Benjadi, Reinhold Egger, Igor Gornyi et al. (+1 more)
Entanglement is a key resource for
quantum technologies. We show that protocols employing
quantum Mpemba effects allow one to exponentially accelerate the generation of
entanglement, or to slow down the decay thereof. Two
entanglement Mpemba effects with different operational meaning are introduced, focusing either on the task of rapidly generating a certain threshold value for
entanglement or on achieving the asymptotic steady-state value. We show that
entanglement Mpemba effects depend on the chosen
entanglement measure. Using cluster elimination methods, many-body
quantum systems also benefit from the exponential speedup of
entanglement generation, as we demonstrate for a dissipative long-range Ising chain.
Read the full abstract ▾
All authors Sara M. Benjadi, Reinhold Egger, Igor Gornyi, Andrea Nava
Optics
Harnessing thermo-optic dynamics for frequency-agile soliton microcombs
Yang Liu, Suwan Sun, Yueguang Zhou et al. (+8 more)
Dissipative Kerr
soliton microcombs enable compact and scalable frequency comb sources for precision metrology, spectroscopy, communications and coherent
LiDAR, where broad and reliable frequency tuning is essential. Thermo-optic response can support thermal locking during
soliton operation, enabling resonance tracking and thereby extending the tuning range, albeit modestly. However, it also induces pronounced thermal instability during
soliton initiation, hindering reliable access to this extended operating regime and limiting practical deployment in applications requiring frequency agility. Here we show that strong mode coupling reshapes the effective detuning trajectory governing
soliton formation, establishing a distinct operating regime in which thermo-optic response is significantly reinforced and constructively harnessed. In this regime,
soliton formation proceeds without the thermal instability inherent to conventional operation, enabling robust
soliton generation in material platforms previously limited by strong thermal effects. Importantly, the enhanced thermo-optic response strengthens thermal locking during
soliton operation, enabling more effective resonance tracking and substantially extending the tuning range. Leveraging this regime in AlGaAs-on-
insulator multimode microresonators, we demonstrate
soliton generation with a tuning range approaching 100 GHz at a pump power of 32 mW. The same mechanism further enables frequency-agile operation through direct pump-frequency tuning without auxiliary stabilization, allowing massively parallel chirped comb generation with more than 90 channels exhibiting frequency excursions exceeding 10 GHz. These results establish a general operating principle for transforming thermo-optic effects from a limiting factor into an active resource, enabling robust and frequency-agile integrated
soliton microcombs.
Read the full abstract ▾
All authors Yang Liu, Suwan Sun, Yueguang Zhou, Yanjing Zhao, Chaochao Ye, Xinda Lu, Yi Zheng, Leif Kastuo Oxenløwe, Kresten Yvind, Hairun Guo, Minhao Pu
General Relativity and Quantum Cosmology
A Scale-Invariant Theory of the Universe
Julian Barbour and Maria I. R. Lourenço
Modern physics has achieved extraordinary empirical success while retaining much of the absolute, unobservable structure introduced by Newton, largely without questioning its necessity. We investigate how far this structure can be eliminated by adopting a relational ontology guided by Leibniz's principle of sufficient reason. Removing absolute position, orientation, time and, finally, scale leads naturally to a formulation of the gravitational $N$-body problem where only dimensionless ratios are physically meaningful. Within this framework, the scale-invariant variety $V$ becomes a central quantity, providing a measure of structure, a natural ordering of shapes, and an emergent gravitational arrow of time. We argue that the resulting formulation unifies classes of Newtonian solutions previously regarded as distinct, uncovering a possible new
symmetry, suggests a notion of explanation based on timeless spatial correlations rather than temporal
evolution, and points towards a more economical ontology. Although developed in the context of Newtonian
gravity, the principles proposed here may also offer a new perspective on general relativity and
quantum mechanics.
Read the full abstract ▾