Statistical Mechanics
Channel concentration of critical quantum geometry
Qian-Rui Lee and Daw-Wei Wang
The
quantum metric quantifies the total ground-state response along a parameter direction, but does not resolve how excitations share that response. We define channel concentration (CC) as the sum of squared normalized response weights over specified excitation channels, such as momentum blocks. An exact finite-size
theorem yields thermodynamic CCs of 2/3 for the field response of the critical transverse-field Ising model and 1/3 for the half-filled XX pairing response, despite the same leading metric scaling. In finite-size approaches to the XY Lifshitz point, field and anisotropy perturbations yield different concentrations despite a common limiting
Hamiltonian with quadratic dispersion. In a
unitary 1+1-dimensional conformal field theory (CFT) on a circle, we consider a nondegenerate
vacuum in a fixed sector perturbed by one spatially integrated scalar primary. We derive complete zero-momentum energy-level response weights, including descendants. For scaling dimension $0<\Delta<3/2$, these weights determine the normalized response distribution and an exact universal concentration function. The expression reproduces the exact Ising
lattice limit 2/3 and gives approximately 0.8515 for the three-state Potts thermal field, compared with approximately 0.800 from an exponent-only approximation. Finite-size interacting calculations compare concentrations and ranked response weights over many-body energy levels. These exact
benchmarks show which response distinctions total metric scaling misses and guide comparisons with finite-size interacting spectra.
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Quantum Physics
Explanation of the Observed Energy Exchange through the vacuum in Optomechanics
Vincenzo Macrì, Franco Nori and Alessandro Ferreri
In cavity optomechanics, the standard large-detuning regime is commonly described by retaining only the radiation-pressure interaction, while higher-order mirror–field interactions are assumed to be negligible. This approximation, however, fails to provide a microscopic explanation for the
vacuum-mediated heat transfer observed between the mechanical membranes in the experiment of Fong, et.al.,[Nature 576, 243 (2019)], whose physical origin has remained under active debate. Here, using a fully
quantum model, we show that the neglected higher-order optomechanical interactions naturally generate
phonon-
phonon coupling and quantitatively account for the observed energy exchange within the standard optomechanical framework. Building on this microscopic description, we further propose a protocol in which
phonon-
phonon interaction drives a cyclic process enabling net work extraction. Our results establish the fundamental role of higher-order optomechanical interactions and provide a microscopic framework for describing next-generation optomechanical experiments beyond the linear approximation.
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Earth and Planetary Astrophysics
Feeding the Circumplanetary Disk: 3D Simulations of Dust Filtration and Accretion in PDS 70 c
Charles H. Gardner, Andrea Isella, Hui Li et al. (+3 more)
How circumplanetary disks (CPDs) capture and retain solids is central to constraining the timescale for formation of rocky satellites and interpreting submillimeter continuum observations around
giant planets. Here, we investigate the transport of gas and
dust from the circumstellar disk into the CPD, using PDS 70 as our fiducial example. Based on observation-driven parameters, we perform high-resolution 3D adaptive mesh refinement (AMR) hydrodynamic simulations including a multifluid
dust component to study
dust accretion onto
planets with masses of 1 $M_\mathrm{J}$ and 2.5 $M_\mathrm{J}$. We find that the pressure maximum at the gap edge imposes strong, size-dependent
dust filtration, drastically lowering the solid content of the accreting flow. The net
dust-to-gas mass ratio of the material accreting onto the
planet is reduced by roughly two orders of magnitude relative to the outer disk. Only small grains ($\lesssim 61 \mu$m for the 1 $M_\mathrm{J}$ case and $\lesssim 10 \mu$m for the 2.5 $M_\mathrm{J}$ case) are able to accrete efficiently onto the CPD. Despite this filtering, we show that a continuous inflow of small grains can still deliver sufficient mass to build the observed PDS 70 c CPD or a Galilean-like satellite system within a few million years. Because more massive
planets more effectively prevent the
accretion of large grains, the
dust that reaches the CPD is dominated by small particles with low millimeter-wave opacities. Consequently, in the absence of grain growth, interpreting millimeter continuum measurements of CPDs around massive
giant planets may require invoking larger total
dust masses than typically assumed.
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All authors Charles H. Gardner, Andrea Isella, Hui Li, Shengtai Li, Gennaro D'Angelo, Adam M. Dempsey
Strongly Correlated Electrons
Staged emergence of anomalous Hall transport in a correlated uranium Weyl semimetal
Sabin Regmi, Shuxiang Zhou, Chandan K. Singh et al. (+9 more)
Understanding how electronic correlations reshape topological states remains a central challenge in
quantum materials. Here we investigate the uranium ferromagnet UPS using magnetotransport, angle-resolved photoemission spectroscopy, thermodynamic measurements, and first principles calculations. Resonant photoemission reveals narrow U-$5f$ spectral weight at the
Fermi level coexisting with broad incoherent states, consistent with the itinerant/localized duality characteristic of uranium $5f$ electrons. The anomalous
Hall conductivity reaches approximately $4.5\times10^{2}\,\Omega^{-1}\mathrm{cm}^{-1}$, yet does not simply follow the ordered
magnetic moment. Temperature dependent photoemission reveals relatively little change across $T_C=118$~K, followed by a pronounced redistribution of low-energy $5f$ spectral weight below approximately 90~K. First-principles calculations identify a
symmetry protected Weyl crossing with pronounced Berry
curvature and yield an intrinsic anomalous
Hall conductivity of approximately $9.6\times10^{2}\,\Omega^{-1}\mathrm{cm}^{-1}$. These results demonstrate that
magnetic order, correlated electronic reconstruction, and anomalous
Hall transport develop over distinct but overlapping temperature ranges, revealing how strong correlations reshape topological transport in a uranium Weyl semimetal.
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All authors Sabin Regmi, Shuxiang Zhou, Chandan K. Singh, Alexei Fedorov, Jonathan Denlinger, Zeyu Ma, Yidi Wang, Jennifer E. Hoffman, Peter M. Oppeneer, Dariusz Kaczorowski, Tomasz Durakiewicz, Krzysztof Gofryk
Materials Science
Face-to-face anneal temperature controls lattice parameter in Ta(C,N) virtual substrates for AlGaN power electronics
Noah Zahn, Julia L. Martin, Michelle A. Smeaton et al. (+3 more)
Tantalum carbide (TaC) thin film ”virtual” substrates are a highly desirable material for $\text{Al}_{0.5}\text{Ga}_{0.5}\text{N}$ vertical power electronics devices due to
lattice matching, thermal expansion matching, and metallic conductivity. However, the material has not been demonstrated to support $\text{Al}_{x}\text{Ga}_{1-x}\text{N}$ layers of variable composition $x$, limiting the range of device applications. We present a method to achieve tunable rock salt $\text{Ta}\text{C}_{x}\text{N}_{1-x}$ virtual substrates via a face-to-face annealing of TaC thin films in an $\text{N}_2$ atmosphere. The results suggest that annealing temperatures below $1600\,^{\circ}\text{C}$ promote partial uptake of nitrogen onto carbon and anion vacancy sites to form rock salt $\text{Ta(C,N)}$ with intermediate anion compositions. At temperatures $\ge 1600\,^{\circ}\text{C}$, nitrogen primarily occupies the anion sublattice and the crystalline quality and surface morphology simultaneously degrade coincident with the formation of secondary phases. This study demonstrates the growth and processing parameters necessary to make tunable
lattice constant virtual substrates for $\text{Al}_{x}\text{Ga}_{1-x}\text{N}$ from $x = 0.5\text{-}1$, enabling vertically conducting power electronic devices with reduced defect density at high Al-content.
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All authors Noah Zahn, Julia L. Martin, Michelle A. Smeaton, Renae Gannon, Henry Garland, M. Brooks Tellekamp
Astrophysics of Galaxies
Reducing False Positives in Strong-Lens Searches with Generalized-Mean Consensus of Machine-Learning Ensembles in the Kilo-Degree Survey
Ziqi Li, Rui Li, Xu Huang et al. (+11 more)
Context. In wide-field surveys, the main challenge is not just classifier sensitivity, but the overwhelming number of false positives. Searching for strong lenses among millions to bilions of
galaxies produces many contaminants, making the bottleneck for follow-up inspection and building statistically useful lens samples. Aims. We aim to improve the purity of strong-lens candidate selection in KiDS DR4 by combining several classifiers. The objective is to retain high completeness for known candidates while substantially reducing the fraction of non-lenses. Methods. We trained convolutional,
Transformer-based, and hybrid classifiers, including Li ResNet+, Swin
Transformer variants, Swin-MLP, and DemiLensNet. Their probabilistic outputs were combined at score level using averaging and a generalized mean consensus. The models were tested on simulated KiDS-like lens images and then evaluated on real KiDS DR4 lens candidates embedded in a non-lens sample. Results. On the simulated test set, ensembles show no advantage over the best single models. On the mixed real KiDS test set, the arithmetic mean reduces the false-positive rate at 90% completeness from 0.016-0.020 (the range spanned by the two best individual models) to 0.011 for the seven-model ensemble. The generalized mean reduces it further, to 0.007. Applied to the full LRG and BG samples at the same 90% completeness level, the generalized mean reduces returned candidates by roughly 50% for LRGs and 70% for BGs, relative to the best single model. After visual inspection, we obtain 170 new high-quality candidates (24 Class A and 146 Class B), together with 1706 Class C candidates. Conclusions. Our results demonstrate that the generalized mean consensus of an ML ensemble strategy provides a practical route to reducing the visual inspection workload while preserving a high recovery rate of promising strong-lens candidates.
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All authors Ziqi Li, Rui Li, Xu Huang, Hui Li, Pufan Liu, Liang Gao, Crescenzo Tortora, Nicola N. Napolitano, Xiaoyue Cao, Ran Li, Liqing Chen, Kang Jiao, Valerio Busillo, Yue Dong
Mathematical Physics
Constraints for Physical Gauge Groups Coming from the Causal Action Principle
Felix Finster and Niels Gresnigt
The constraints for the effective local gauge groups stemming from the causal action principle for causal
fermion systems are reviewed. The constraint which are quadratic in the gauge potentials (coming from the so-called bilinear logarithmic terms) are shown to make a connection between the structures of Lie
algebras and Clifford
algebras. This connection is worked out systematically starting from general
chiral potentials corresponding to the gauge group $\mathrm{U}(N) \times \mathrm{U}(N)$. The general results are illustrated in various examples.
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High Energy Physics (Phenomenology)
A New Probe of Strongly-Interacting Dark Sector using Neutrino Telescopes
Jose A. Macias Cruz, Christopher V. Cappiello, P. S. Bhupal Dev et al. (+1 more)
A confining dark sector modeled after
quantum chromodynamics provides a well-motivated framework for strongly-interacting dark matter. We show that dark vector
mesons in a confining dark sector can be resonantly produced in high-energy
neutrino scattering on the
cosmic neutrino background, generating a distinctive absorption feature in the
cosmic neutrino energy spectrum. Unlike conventional attenuation effects, this feature directly reflects the mass spectrum of dark resonances and can therefore serve as a spectroscopic signature of a strongly-interacting dark sector. We find that a broad range of dark-sector parameter space is within the reach of future
neutrino telescopes, including IceCube-Gen2
Radio. Our proposal thus turns the
cosmic neutrino background into a target for discovering dark-sector resonances, while simultaneously providing a novel probe of dark sector interactions with
neutrinos.
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All authors Jose A. Macias Cruz, Christopher V. Cappiello, P. S. Bhupal Dev, Suchita Kulkarni
Atmospheric and Oceanic Physics · Cross-listed from cs.LG
Learning Prognostic Variables for AI Convective Parameterizations via Symbolic Distillation
Jurij Schönfeld, Tom Beucler, Julien Savre et al. (+2 more)
Hybrid AI-physics
climate modeling aims to improve coarse (~100km-resolution) Earth system models by learning to parameterize subgrid processes from high-fidelity data. However, this so far mostly involves local-in-time, diagnostic parameterizations, in which the subgrid state depends only on the current coarse state with no
memory of previous states, which is unrealistic for processes such as convection that have intrinsic persistence. To address this, we enhance local-in-time parameterizations by learning prognostic variables that compactly carry important, additional past information where no explicit sub-grid information is available. First we compress past information into a low-dimensional latent space using an autoencoder, which then informs a neural network trained to parameterize targeted subgrid-scale processes. We then replace the autoencoder with symbolic equations that govern the time
evolution of the latent variables, yielding additional prognostic
memory variables that can be integrated alongside the resolved atmospheric state. We evaluate this approach on two systems: the Lorenz-96 model (online) and surface precipitation from high-resolution atmospheric simulations (offline). A forced multivariate linear ordinary differential equation recovers most of the added value achieved by the autoencoder-based approach in both experiments. Benchmarked against diagnostic parameterizations without
memory, our
memory-informed approach improves
climate statistics and temporal structure, including a realistic diurnal cycle of tropical land precipitation.
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All authors Jurij Schönfeld, Tom Beucler, Julien Savre, Steven Sherwood, Veronika Eyring
Atomic Physics
Anomalously enhanced lifetimes of low angular momentum Rydberg states in singly charged alkaline-earth metal ions
Simon Euchner, Weibin Li and Igor Lesanovsky
Trapped ions excited to high-lying electronic states, so-called Rydberg states, open new opportunities for
quantum simulation and
quantum computing. Generally, the fidelity of
quantum coherent operations critically depends on the longevity of Rydberg states. However, scaling laws predict that the lifetimes of Rydberg states in singly charged alkaline-earth metal ions are 16 times shorter, compared to their neutral atom counterparts. Here, we show that this is not generally the case. We report an anomalous lifetime enhancement of certain low angular momentum ionic Rydberg series by factors larger than eight. The anomaly is present at both zero and finite temperature, although it is caused by different mechanisms. At zero temperature, the anomalously enhanced lifetimes are caused by accidental cancellations of the relevant dipole transition
matrix elements, while at room temperature the anomaly originates from the enlarged energetic separation of ionic Rydberg levels with respect to neutral-atom levels.
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High Energy Physics (Theory)
Measuring correlations using local and nonlocal quenches
Alexey G. Mikhaylenko and Andrew G. Semenov
We present a theoretical proposal for measuring correlation functions in a
quantum field system based on the use of
quantum quenches. Using the examples of massive and massless scalar field theories, we show that a short-term perturbation of the system leads to a dependence of the further
evolution of the average field on the initial state's correlation functions. Considering two types of perturbations, namely local and nonlocal quenches, we show which correlation functions can be measured in each of these cases. The proposed procedure can be applied to study non-Gaussian correlations.
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Earth and Planetary Astrophysics
Upside down: GJ3090 b the first retrograde exoplanet around an M dwarf detected with NIRPS
Y. Carteret, V. Bourrier, L. Parc et al. (+57 more)
The angle between
stellar spin axis and planetary orbital plane can provide key insights into the formation and dynamical
evolution of planetary systems. In particular, this measurement in multi-
planet systems can be used to further discriminate between different competing migration scenarios. We present six transit observations of the sub-Neptune GJ3090 b obtained with NIRPS and HARPS. GJ3090 b is the inner
planet of a confirmed multi-
planet system orbiting an M
dwarf (M2). Using high spectral resolution and high temporal cadence spectroscopic observations, we analyzed the Rossiter-McLaughlin (RM) effect induced by GJ3090 b to determine its orbital obliquity. Through the RM revolutions technique, we find that the
planet is on a retrograde orbit with a derived 3D obliquity of $\psi = 136^{+24}_{-18}\,\mathrm{deg}$. We find no evidence of massive outer planetary or wide
stellar binary companions, which disfavors scenarios involving gravitational perturbations from a massive body and instead points toward a
primordial misalignment of the protoplanetary disk. Our results establish GJ3090 b as the first
planet on a retrograde orbit discovered around an M
dwarf and the first highly misaligned confirmed multi-
planet system without a known massive companion. We further propose late secondary disk
accretion around GJ3090, in which the disk is not expected to be aligned with the
stellar spin axis, followed by disk-driven migration as the most likely mechanisms to explain the observed architecture. This work also illustrates the capability of the RM revolutions technique when applied to near-infrared data to probe orbital architectures of the smallest
planets around M
dwarfs that have remained mostly inaccessible.
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All authors Y. Carteret, V. Bourrier, L. Parc, A. Winter, R. Allart, I. de Castro Leão, F. Bouchy, V. M. Passegger, C. Cadieux, P. Lamontagne, É. Artigau, F. Baron, S. C. C. Barros, B. Benneke, X. Bonfils, M. Bryan, B. L. Canto Martins, R. Cloutier, E. Cristo, J. Gagné, N. J. Cook, N. B. Cowan, J. R. De Medeiros, X. Delfosse, R. Doyon, X. Dumusque, D. Ehrenreich, J. I. González Hernández, D. Lafrenière, C. Lovis, L. Malo, C. Melo, L. Mignon, C. Mordasini, F. Pepe, R. Rebolo, J. Rowe, N. C. Santos, D. Ségransan, A. Suárez Mascareño, S. Udry, D. Valencia, G. Wade, K. Al Moulla, R. G. de Souza Barros de Amorim, L. Dang, E. Deibert, D. O. Fontinele, T. Forveille, Y. G. C. Frensch, R. de Lima Gomes, D. Mounzer, S. Pelletier, R. Rosener, B. N. Skinner, A. Srivastava, A. K. Stefanov, V. Vaulato, J. P. Wardenier, D. Weisserman
Fluid Dynamics
Resolved multiple-droplet evaporation
Alexander W Wray
A simple, accurate asymptotic formula is derived for the spatially resolved evaporative flux from multiple spherical-cap droplets of arbitrary contact angle. Kelvin transforms are used to determine the exact response of a spherical-cap droplet to a point source, with extensions to higher multipoles. This yields explicit formulae for evaporative shielding and reveals a universal spatial structure in the point-source problem. Resolving the spatial variation enables the determination of the associated
liquid flow and particle transport. The resulting flux is used to derive an explicit measure of shielding-induced
liquid transport.
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High Energy Physics (Theory)
Quantum vacuum inversion and multi-kink unbinding in the non-degenerate double sine-Gordon model
Jonathan Lozano-Mayo
Quantum fluctuations can unbind a composite
soliton while the correction to its mass stays small. We show this beyond perturbation theory for the multi-kinks of the non-degenerate double sine-Gordon model. At one loop the
vacuum at the centre of the multi-kink becomes the true
vacuum at a coupling of order the classical lifting of the
vacua. Tensor-network calculations of the
lattice theory show that this inversion survives beyond one loop and has a continuum limit, and that the Gaussian effective potential captures it. On finite chains the multi-kink unbinds when the tension of the string of central
vacuum between its two halves falls through zero
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Quantum Physics
Overcoming the Hong-Ou-Mandel interference limitation for the second photon from a two-photon cascade
Raphael Joos, Michal Vyvlecka, Tim Strobel et al. (+8 more)
Quantum emitters such as
semiconductor quantum dots can provide entangled
photon pairs emitting from a system of cascaded states. However, the resulting temporal correlation between the two
photons from the three-level ladder system has been shown to set a limit on the achievable two-
photon interference. In this work, we show that such limitation, for
photons emitted by the second transition, is only due to reduced temporal overlap at the interference beam splitter. We investigate this theoretically and experimentally by determining time-resolved four-
photon coincidences between two successively emitted
photon pairs. Post-emission synchronization shows the recovery of maximum interference visibility; in prospective
quantum networks this could be achieved via deterministic
quantum memories.
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All authors Raphael Joos, Michal Vyvlecka, Tim Strobel, Benjamin Breiholz, Furkan Aglarci, Ponraj Vijayan, Hans-Georg Babin, Arne Ludwig, Michael Jetter, Simone L. Portalupi, Peter Michler
Strongly Correlated Electrons
Quantum-interference-driven orbital density wave and high-temperature superconductivity in trilayer nickelates
Youichi Yamakawa and Hiroshi Kontani
Intertwined charge-density-wave (CDW) and
spin-density-wave (SDW) orders are a hallmark of high-temperature superconducting multilayer nickelates. In trilayer La4Ni3O_{10}, charge correlations develop at temperatures above the onset of long-range
spin order, and the characteristic ordering wavevectors satisfy $Q_{cdw} \approx 2Q_{sdw}$. Here, using a density-wave equation with vertex corrections, we show that
quantum interference between short-range SDW fluctuations at $q \approx Q_{sdw}$ on the outer NiO2 layers generates an inter-outer-layer bond order at $Q_{cdw} \approx 2 Q_{sdw}$. This bond order induces a pronounced inner-layer-centered orbital order, with antiphase modulations of the Ni $d_{3z^2-r^2}$ and $d_{x^2-y^2}$ occupations, producing strong orbital polarization but only weak total charge modulation. This intertwined bond-and-orbital order accounts for the layer-selective electronic reconstruction inferred from NMR/NQR and is consistent with Raman spectroscopy and scanning tunnelling microscopy measurements. The same orbital and
spin fluctuations also cooperate to stabilize $s_{\pm}$-wave superconductivity through $M_z$ mirror-parity selection rules. Our results provide a unified microscopic framework for intertwined density-wave order and high-Tc superconductivity in multilayer nickelates.
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Materials Science
Scandium diboride: a semi-metallic, lattice, thermally matched substrate for vertical AlGaN power electronics
MVS Chandrashekhar, Daniel Joel Harrison, Ahamed Raihan et al. (+22 more)
We report the properties of hexagonal (space group P6/mmm) scandium diboride ($\mathrm{ScB}_2$) single
crystals grown by a
laser diode floating zone method at growth rates of ~1mm/hr under B-rich conditions with (002) rocking curve widths $\Delta\omega$=38” approaching the quality of commercial SiC/GaN substrates.
Lattice expansion measurements reveal matching to $\mathrm{Al_{0.55}Ga_{0.45}N}$ with a coefficient of thermal expansion ~5ppm/K at typical AlGaN growth temperatures, enabling thick AlGaN layers for ultra-wide bandgap (UWBG) power electronics >1kV. We measure semi-metallic room temperature resistivity ~15$\mu\Omega$ cm, climbing to ~93$\mu\Omega$ cm at 773K with a $T^2$ dependence effectively eliminating substrate parasitic resistance, the limiting factor in exploiting the full potential of UWBG. The Debye temperature $\theta_{D,ScB_2}$ from heat capacity and
lattice expansion is ~850K well matched to $\theta_{D,ScB_2}$, but lower than the 1100K measured for Sc-rich growth conditions. We discuss Debye matching as a key substrate codesign criterion providing significant overlap in
phonon modes for heat removal and thermal matching during AlGaN growth. The competitive thermal conductivity at room temperature 53W/mK is half that from full first principles calculations, a discrepancy we attribute to the presence of Sc-vacancies generated by B-rich growth. while the resistivity is ~2x the theoretical value, indicating that both electrons and
phonons play equal role in thermal transport. The smooth ~2.5nm rms roughness surface enables advanced heat removal modalities through engineered
phonon bridges and
phonon polaritons in $\mathrm{ScB}_2$/AlGaN interfacial
heterostructures, potentially allowing ~10-100x increase in power handling over state-of-the-art GaN/SiC.
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All authors MVS Chandrashekhar, Daniel Joel Harrison, Ahamed Raihan, Astrid D. Kengne, R. Shipra, Han Xie, Tasnia Jabin, Monte Hendrix, Ethan Scott, Roshan S. Annam, Sharad Mahatara, Evan N. Crites, Allana G. Iwanicki, Luke J. Meiler, Maxime Siegler, Renae N. Gannon, Steven R Spurgeon, Ashutosh Giri, Rajeswari Kolagani, Joshua A. Burrow, Stephan Lany, Patrick Hopkins, Tyrel M. McQueen, Michael Spencer, Satya Khushwaha
Strongly Correlated Electrons
Anisotropic Surface State Band Splitting and Low Energy Flat Bands in 3d Correlated Topological Kondo Insulator Candidate FeSb$_2$
Ziling Cao, Jie Pang, Yu Xu et al. (+22 more)
FeSb$_2$ is a correlated narrow-gap
semiconductor that has often been discussed as a $3d$-electron Kondo
insulator candidate and exhibits a low-temperature resistance plateau with possible surface-dominated conduction. We carried out a systematic high-resolution
laser-based angle-resolved photoemission spectroscopy (ARPES) study of FeSb$_2$ to investigate its electronic structure. The surface states around the zone center show clear anisotropic splitting. When the temperature is lowered into the resistance plateau regime ($<6\,\mathrm{K}$), the surface states remain robust, but their photoemission peaks become much sharper and gain spectral weight. Two distinct flat-band-like features are observed at low energy. One is located at $\sim$127 meV below the
Fermi level, which exists only along a specific high-
symmetry direction, while the other is located at $\sim$70 meV below the
Fermi level and is present along all the measured momentum cuts around the zone center. These results provide new information to understand the renormalization effects, the resistance plateau, and the topological nature of FeSb$_2$.
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All authors Ziling Cao, Jie Pang, Yu Xu, Taimin Miao, Bo Liang, Wenpei Zhu, Neng Cai, Mingkai Xu, Jumin Shi, Yingjie Shu, Yiwen Chen, Jiachen Wang, Shenjin Zhang, Fengfeng Zhang, Feng Yang, Zhimin Wang, Qinjun Peng, Zhihai Zhu, Xintong Li, Hanqing Mao, Guodong Liu, Zuyan Xu, Youguo Shi, Lin Zhao, X. J. Zhou
Instrumentation and Methods for Astrophysics
The Sun can flip the shielding effect of added spacecraft mass
Yasser Maghrbi and Nelson Christensen
Spacecraft structure is usually treated as shielding against energetic particles. We find that the Sun can reverse the effect of adding that structure. Free-falling test masses are the inertial references of gravitational-wave observatories and equivalence-principle experiments; charge accumulated on them couples to stray electric fields and produces acceleration noise that limits sensitivity. In a LISA-like system, increasing the surrounding aluminium from 16 to 24 g cm -2 reduces the stopping-
proton population by (2.3 $\pm$ 0.5)% at
solar minimum but increases it by (17.0 $\pm$ 1.0)% at
solar maximum, the crossover lying in the deep-
solar-minimum regime. Complete 2-24 g cm -2 mass curves show a broad maximum at
solar minimum but a monotonic rise at maximum. The reversal arises because added material both attenuates incident
protons and feeds a
nuclear-processed population into the stopping-energy window. A first-order projection onto published charging rates gives changes of about -2% and +11% in the net charging rate, affecting charge accumulation, discharge requirements and the associated noise budget. The sign of a structural trade is therefore not fixed by the structure alone.
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Statistical Mechanics
Navier-Stokes hydrodynamics near the critical point with out-of-equilibrium modes
Md Hasanujjaman, Golam Sarwar, Mahfuzur Rahaman et al. (+2 more)
We investigate how slow out-of-
equilibrium modes (OEM), introduced to extend the regime of validity of hydrodynamics near the critical point, fundamentally reshape the power spectrum of dynamical density fluctuations. We have used the equation of motion of slow modes for the situation when the extensive nature of thermodynamics is not altered due to the introduction of OEM. We find that the extensivity condition puts an extra constraint on the coupling of OEM with the four divergence of velocity. In the absence of OEM, the dynamic structure factor exhibits three Lorentzian peaks, one at zero frequency ($\omega$), called Rayleigh peak and the other two called Brillouin peaks located symmetrically about $\omega=0$. When the system is away from the critical point the inclusion of the OEM preserves the
symmetry of the distributions but all the peaks acquire reduced widths and the Brillouin peaks adopt unequal heights. Irrespective of the value of OEM (zero or nonzero) the Brillouin peaks vanish near the critical point. The width of the Rayleigh peak substantially reduced in presence of OEM. Such reductions of the widths in presence of the OEM indicates the reduction in the decay rate of the fluctuation which leads to slowing down of decay of the fluctuations, a distinctive feature of the critical point.
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All authors Md Hasanujjaman, Golam Sarwar, Mahfuzur Rahaman, Abhijit Bhattacharyya, Jane Alam
Superconductivity
Electronic Reconstruction Towards Topological Superconductivity in FeTe
Hongtao Rong, Yang Ge, Zi-Jie Yan et al. (+13 more)
The recent discovery of intrinsic superconductivity in stoichiometric FeTe films has renewed interest in the Te-rich end member of the iron chalcogenides for studies of unconventional and topological superconductivity, yet its intrinsic electronic structure remains unresolved. In this work, we combine molecular beam epitaxy, angle-resolved photoemission spectroscopy (ARPES), electrical transport measurements, density functional theory, and embedded dynamical mean-field theory to track the electronic reconstruction of 20-unit-
cell FeTe films as Te annealing progressively removes excess interstitial Fe and drives the system from an
antiferromagnetic metal to a
superconductor. We find that this
evolution is accompanied by recovered quasiparticle coherence, reduced electronic correlations, a Lifshitz transition, and a topological phase transition, yielding dxy-dominated hole and electron pockets that favor inter-pocket scattering. In addition, a shallow dxz/dyz-derived hole band located about 2 meV below the
Fermi level may provide an incipient-band pairing channel, while scattering between the two electron pockets at M may offer additional pairing channels. High-resolution polarization-dependent
laser ARPES measurements further reveal a topological surface state whose circular dichroism is consistent with the expected orbital-angular-momentum texture of stoichiometric FeTe. These results establish the intrinsic low-energy electronic structure of superconducting FeTe and identify the electronic states most relevant to superconductivity. The coexistence of intrinsic superconductivity and a topological surface state establishes stoichiometric FeTe as a promising platform for exploring topological superconductivity and possible Majorana bound states.
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All authors Hongtao Rong, Yang Ge, Zi-Jie Yan, Haoran Lin, Bing Xia, Xiaoda Liu, Zihao Wang, Pu Xiao, Lok-Kan Lai, Stephen Paplini, Jiatao Song, Jiangang Yang, Peter J. Hirschfeld, Shuolong Yang, Jiabin Yu, Cui-Zu Chang
Biological Physics
Towards Accurate Prediction of Mutation-Induced Changes in Protein Structure
Zhuoyi Liu, Alex Calabrese and Corey S. O'Hern
Proteins can possess numerous mutations relative to their wild-type amino acid sequences with minimal impact to their structure and function. However, in other cases, even a single amino acid mutation relative to the wild-type sequence can lead to a large change in structure or even a disease phenotype. While the accuracy of wild-type
protein structure prediction has improved significantly in recent years, it remains difficult to accurately predict the structure of mutant
proteins. Here, we characterize the local mutation-induced structural changes in
proteins for a
dataset of wildtype and the corresponding single-amino acid mutant x-ray
crystal structures from the
Protein Data Bank (PDB). We find that mutation-induced structural changes in these
proteins are localized at the site of the mutation, decaying rapidly with increasing spatial distance from the mutation site. In addition, we evaluate how well AlphaFold3 can recapitulate the observed mutation-induced structural deformations in the x-ray
crystal structures. We find that the accuracy of the AlphaFold3 predictions decreases strongly with increasing mutation-induced deformation. In contrast to the results for AlphaFold3, the Pearson correlation between a single physical feature, i.e. the change in solvent accessibility, and the mutation-induced deformation does not depend on the magnitude of the deformation. Our results and analyses provide a framework for further studies aimed at predicting the structural changes in
proteins caused by single amino acid mutations.
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High Energy Astrophysical Phenomena
Jet variability in small mass ratio supermassive black hole binaries
Jay V. Kalinani, Manuela Campanelli, Michail Chabanov et al. (+4 more)
We present three-dimensional general relativistic magnetohydrodynamic simulations of a precessing supermassive black hole binary with mass ratio q=1/7, embedded in a circumbinary disk. We investigate how dynamics within the binary cavity launch and shape a relativistic jet to thousands of gravitational radii. The primary black hole dominates both
accretion and jet power, while the smaller black hole repeatedly crosses and shocks the inner
accretion flow. These passages of the secondary drive magnetized gas alternately into the upper and lower jet funnels, producing disturbances that propagate outward as quasi-periodic
outflows. Although the inner flow is perturbed twice per orbit, each jet lobe shows one dominant
outflow per orbit. On longer timescales, the jet precesses, reverses its
magnetic handedness, and undergoes two weak phases. The first results from a reorientation of the primary
spin and is followed, after the jet recovers, by a reversal in the circulation of the projected
magnetic field. The second weak phase occurs as the secondary's orbit becomes nearly coplanar with the circumbinary disk, reducing the gas and
magnetic flux reaching the primary. Together, these results connect cavity dynamics to large-scale jet variability and predict a set of correlated jet signatures whose relative timing and causal ordering may provide stronger evidence for a small-mass-ratio supermassive black hole binary than any one feature alone.
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All authors Jay V. Kalinani, Manuela Campanelli, Michail Chabanov, Maria Chiara de Simone, Carlos O. Lousto, Helvi Witek, Yosef Zlochower
Quantum Physics
Trade-offs and experimental feasibility of nonlocal polygamy with two-outcome Bell inequalities
Josep Batle, Tomasz Rybotycki, Tomasz Białecki et al. (+2 more)
Entanglement and Bell nonlocality have different sharing constraints across subsystems of a multipartite
quantum system. We examine simultaneous violations of Bell inequalities with two-outcome observables and two or three measurement settings per party. We identify configurations whose simultaneous violations can be demonstrated on IBM
Quantum hardware, and derive bounds and trade-off relations for several polygamous configurations. The results connect experimental capabilities of
quantum computers with mathematical methods for studying the limits of
quantum correlations.
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All authors Josep Batle, Tomasz Rybotycki, Tomasz Białecki, Piotr Gawron, Adam Bednorz
Superconductivity
Generalized conditions for odd-frequency pairing in superconducting systems
Florian Kayatz, Annica M. Black-Schaffer and Jorge Cayao
Odd-frequency superconducting pairing has been predicted to arise in many systems and is known to lead to phenomena such as paramagnetic Meissner response and long-range superconducting proximity effect. Here, we provide generalized necessary and sufficient conditions for odd-frequency pairing appearing in any superconducting system, from bulk
superconductors to superconducting hybrid structures. This generalizes an earlier first-order expression in multiband bulk
superconductors to all superconducting systems and to all orders, in both order parameter and frequency. We then apply the derived conditions to several systems, including superconducting-ferromagnet and superconducting Josephson junctions, as well as a transition metal dichalcogenide monolayer proximitized by a conventional
superconductor, where the generalized conditions are used to understand the properties of the superconducting state.
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General Relativity and Quantum Cosmology
Constraining the geometry of rotating black holes with eikonal QNMs
Ciro De Simone, Sebastian H. Völkel and Kostas D. Kokkotas
Quasinormal modes of black holes provide a central avenue for confronting general relativity with gravitational-wave observations from the ringdown stage of compact binary coalescence. However, inferring black-hole properties or the background spacetime requires theory-dependent input. In this work, we connect a calibrated eikonal method, which relates quasinormal mode shifts to local metric properties near the light ring, with the underlying rotating black hole metric. Using
Bayesian inference, we compare a metric-specific model based on the global Konoplya-Rezzolla-Zhidenko parametrization with a metric-agnostic approach based on local values and radial derivatives of the metric functions at the light ring. For each model, we perform both one-parameter and simultaneous multi-parameter analyses and quantify how their priors map onto the same local quantities. We find that uniform priors on the metric-specific coefficients can induce strongly nonuniform and skewed priors on these local metric quantities. For an injection compatible with general relativity, both models remain consistent with Kerr and yield similar posteriors for the orbital frequency and Lyapunov exponent despite their different induced priors. For injections representing deviations from general relativity, one-parameter analyses can fail to recover the injected local deviations and, in the metric-specific case, can bias the global metric reconstruction. The multi-parameter analyses of both models yield consistent constraints, suggesting sufficient robustness. However, they introduce substantial degeneracies and differences in marginalized parameters, demonstrating practical limitations when considering more flexible models. Finally, we apply the framework to approximate posterior information from the ringdown analysis of GW250114 and find that both models are consistent with the Kerr metric in general relativity.
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High Energy Physics (Theory)
The Generalized Uncertainty Principle. Massless QED Renormalization
Ezequiel Valero, Héctor Gisbert and Victor Ilisie
The effective-field-theory interpretation of generalized uncertainty principle (GUP) deformations does not by itself establish whether their tree-level operator content is closed under renormalization. We investigate this question in massless GUP-deformed
quantum electrodynamics at one loop and to first order in the deformation parameter. We compute the ultraviolet divergences of the relevant Green functions and determine the counterterm structure. Our central result is that, after eliminating redundant operators, renormalization requires only one independent physical counterterm beyond those associated with the tree-level theory: an axial-axial four-
fermion interaction. The original deformation therefore admits a minimal radiative completion at this order. We derive the leading logarithmic running of the induced Wilson coefficient and discuss its operator-level correspondence with the contact interaction arising in Einstein-Cartan
gravity.
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Astrophysics of Galaxies
A Newly Discovered VVVX Star Cluster Surfing the Galactic Disk
Elisa R. Garro, José G. Fernández-Trincado, Casmir O. Obasi et al. (+15 more)
We report the discovery of Garro 04, a previously unidentified
stellar cluster toward the
Galactic disc, uncovered as part of the ESO/KMOS VVVX-GalCen Spectroscopic Survey. This object was serendipitously confirmed as a
stellar overdensity in the VISTA Variables in the Vía Láctea eXtended (VVVX) survey footprint and subsequently confirmed through medium-resolution $K$-band spectroscopy obtained with the K-band Multi Object Spectrograph (KMOS) at the ESO Very Large
Telescope. The combined photometric and spectroscopic analysis reveals a coherent
stellar population with common radial velocities and chemical properties, supporting its classification as a genuine
star cluster rather than a statistical fluctuation of the disk field. We derive the fundamental properties of Garro 04, including its structural parameters, distance, kinematics, and compute its orbital properties, finding that its motion remains confined to the
Galactic disk region. Finally, our analysis suggests that Garro~04 is likely an old open cluster, or an object straddling the boundary between the canonical globular and open cluster classifications, with an estimated Age $ = 5 \pm 2$ Gyr and a
metallicity of $\mathrm{[Fe/H]} = -0.5 \pm 0.2$, finding an excellent agreement between the photometric and spectroscopic determinations.
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All authors Elisa R. Garro, José G. Fernández-Trincado, Casmir O. Obasi, Dante Minniti, Matías Gómez, Roberto K. Saito, Javier Alonso-García, Alonso Luna, Valentin D. Ivanov, Maria Gabriela Navarro, Sara Federle, Bernardo P. L. Pereira, Beatriz Barbuy, Devika Bhadrakumar Sindhu, Bruno Dias, Tali Palma, Ilaria Petralia, Sasi Saroon
Applied Physics
A State-Space Framework for trivial and Topological Metamaterial Stochastic Analysis
Luiz Henrique Marra da Silva Ribeiro, Abhilash Sreekumar, Vinícius Fonseca Dal Poggetto et al. (+4 more)
Topological phononic
crystals and elastic metamaterials support edge states defined by global topological invariants, offering a route toward vibration-control and wave-guiding devices that remain functional in the presence of defects. However, manufacturing-induced spatial variability can perturb these invariants and compromise their robustness, making its quantification essential during design. In this work, we first demonstrate that a previously proposed linear time-varying (LTV) formulation is mathematically equivalent to the spectral element method based on transfer
matrices for elementary rod, Saint-Venant shaft, and Euler-Bernoulli beam theories. The deterministic formulation is then extended to
stochastic analyses through a
stochastic linear time-varying (SLTV) framework. The proposed methodology combines Monte Carlo simulations with
stochastic Fourier series and an analytical Karhunen–Loève expansion, providing closed-form
stochastic fields and their derivatives required by the LTV formulation. The SLTV approach enables the computation of
stochastic dispersion diagrams and forced responses of one-dimensional waveguides with arbitrarily varying geometry and mechanical properties. Because the LTV-based transition
matrix isolates individual wavemodes without requiring the mode tracking needed by conventional eigenproblem-based formulations, the framework is particularly suited for evaluating topological invariants, specifically the Zak phase, and assessing the robustness of topological bands under spatial variability. Numerical results for rods, shafts, and Euler-Bernoulli beams demonstrate the applicability of the proposed framework as a unified methodology for deterministic and
stochastic analyses of trivial and topological periodic waveguides under continuous spatial uncertainty.
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All authors Luiz Henrique Marra da Silva Ribeiro, Abhilash Sreekumar, Vinícius Fonseca Dal Poggetto, Vicent Romero-García, Dimitrios Chronopoulos, Carlos De Marqui Jr., José Roberto de França Arruda
High Energy Physics (Theory)
Finite-Time Doppler Covariance Spectroscopy in the AdS/CFT correspondence
Feiyi Liu, Shiyang Chen and Yang Wang
From a
holographic perspective, we formulate an exact finite-duration covariance framework that resolves chirality in the AdS/CFT correspondence. In a rotating BTZ black hole spacetime, relative motion between two boundary controls converts sum-frequency matching on the compact boundary cylinder into discrete velocity resonances indexed by the angular momentum of the scalar field. Because the complete real-control covariance also contains difference-frequency sectors, a two-setting phase cycle with a common switching window cancels them exactly at finite duration and reconstructs the resonant pair contribution from complete positive-semidefinite covariance
matrices. For an isolated angular mode, reconstructed pair responses at opposite resonance velocities sample the boundary spectrum at opposite angular momentum and a common control-selected frequency. Their normalized contrast cancels reflection-symmetric control factors and the state-independent operator normalization, yielding a finite-linewidth
estimator of the reflected-mode BTZ contrast. Under the stated smoothness and moment conditions, common centered even narrowing windows give a bias beginning at quadratic order in linewidth. A real-projection leakage bound controls contamination from neighboring modes. Long-pulse calculations with the exact BTZ spectrum verify phase-cycle reconstruction and quadratic linewidth scaling. Bath-weighted calculations with exact truncated transfer amplitudes establish convergence to this baseline. Under the default controls, complete-sum contrasts for the first two nonzero angular modes reconstruct the reference-state rotation parameter at fixed mean inverse temperature with subpercent deterministic bias in the untruncated Gaussian limit. The inferred rotation parameter fixes the horizon parameters of the rotating BTZ black hole once the mean inverse temperature and AdS radius are known.
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