Astrophysics of Galaxies
The complex stellar system M 22: confirming abundance variations with high precision differential measurements
M. McKenzie, D. Yong, A. F. Marino et al. (+8 more)
M 22 (NGC 6656) is a chemically complex globular cluster-like system reported to harbour heavy element abundance variations. However, the extent of these variations and the origin of this cluster is still debated. In this work, we investigate the chemical inhomogeneity of M 22 using differential line-by-line analysis of high-quality (R = 110,000, S/N = 300 per pixel at 514 nm) VLT/UVES spectra of six carefully chosen red
giant branch
stars. By achieving abundance uncertainties as low as ~0.01 dex (~2 per cent), this high-precision data validates the results of previous studies and reveals variations in Fe, Na, Si, Ca, Sc, Ti, Cr, Mn, Co, Ni, Zn, Y, Zr, La, Ce, Nd, Sm and Eu. Additionally, we can confirm that the cluster hosts two
stellar populations with a spread of at least 0.24 dex in [Fe/H] and an average s-process abundance spread of 0.65 dex. In addition to global variations across the cluster, we also find non-negligible variations within each of the two populations, with the more metal-poor population hosting larger spreads in elements heavier than Fe than the metal-rich. We address previous works which do not identify anomalous abundances and relate our findings to our current dynamical understanding of the cluster. Given our results, we suggest that M 22 is either a
nuclear star cluster, the product of two merged clusters, or an original building block of the Milky Way.
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All authors M. McKenzie, D. Yong, A. F. Marino, S. Monty, E. Wang, A. I. Karakas, A. P. Milone, M. V. Legnardi, I. U. Roederer, S. Martell, D. Horta
Quantum Physics
Reshaping quantum annealing landscapes with diagonal catalysts
Andrés N. Cáliz, Carlos Ramon-Escandell, Finnley Paolella et al. (+4 more)
Quantum annealing is often limited by population trapped in local minima many
spin flips from the solution. We introduce a mathematical framework to understand the connection between energy and Hamming distance in optimization problems. Using this, we build ZZ-catalysts from ground-state patterns of small frustration-free subproblems that make configurations far from the solution less energetically competitive. On sparse problems they multiply the near-solution probability at short sweeps, with gains persisting on fully-connected models and tunable via subproblem choice.
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All authors Andrés N. Cáliz, Carlos Ramon-Escandell, Finnley Paolella, Josep Bosch, Jan Nogué, Arnau Riera, Jordi Riu
Soft Condensed Matter
Gelation of functional peptides by trivalent cations at the air-water interface
Stephen A. Crane, Felipe Jimenez Angeles, Monica Olvera de la Cruz et al. (+2 more)
We report a mechanism for gelation at fluid interfaces driven by multivalent-cation-mediated bridging. At the air-water interface, peptides with bound lanthanide cations undergo a coordination-geometry transition that converts the metal from a single-peptide bound state to a multi-peptide bridging state, driving charge inversion and gel formation. Surface adsorption and non-ideal interfacial electrostatics are implicated in this transition. The gel is stabilized by reversible metal-ligand coordination bonds that resist bulk salt screening, fundamentally distinct from electrostatic charge-inversion gelation in
proteins. This reveals the breakdown of the peptide's coordinating sphere as a distinct pathway for interfacial gelation, independent of the diffuse electrostatic mechanisms governing bulk
protein aggregation.
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All authors Stephen A. Crane, Felipe Jimenez Angeles, Monica Olvera de la Cruz, Ivan J. Dmochowski, Kathleen J. Stebe
Nuclear Theory
Towards compressed baryonic matter densities: D meson diffusion
Dani Rose J Marattukalam, Manpreet Kaur, Arvind Kumar et al. (+1 more)
We study the spatial
diffusion coefficient and the momentum transport coefficients of D
mesons through a dense
nuclear medium in the relaxation time approximation of the kinetic theory. The in medium modifications of the D
meson transport properties are computed in the
chiral SU(3) hadronic model. Relaxation time is estimated using dilute and degenerate gas approximations for low and high baryonic densities, respectively. We have noticed that relaxation time and spatial
diffusion of D
meson decrease rapidly in the low density dilute gas domain and mildly in the high density degenerate gas domain. The detailed result of the present work on D
meson diffusion is quite contemporary and important towards the compressed baryonic matter densities which can be assessed in future heavy ion collision experiments.
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All authors Dani Rose J Marattukalam, Manpreet Kaur, Arvind Kumar, Sabyasachi Ghosh
General Relativity and Quantum Cosmology
Acoustic Firewalls: Analogue Gravity Perspective on the AMPS Paradox
Nikolay S. Akintsov, Artyom P. Nevecheria, Stepan N. Andreev et al. (+1 more)
The monogamy of
quantum entanglement, applied by Almheiri-Marolf-Polchinski-Sully (AMPS) to black holes, obstructs a smooth horizon
vacuum after the Page time. We transcribe this argument to Hawking-like
phonon radiation from a sonic horizon in the Unruh acoustic metric. An exact purity identity shows that post-Page-time unitarity forces the
entanglement between an outgoing
phonon and its interior partner to vanish, selecting a non-Hadamard (Boulware-like)
phonon state, which we define as an acoustic firewall. Its renormalized stress tensor differs from the smooth state by a constant, negative near-horizon flux, and the thermal-atmosphere energy density it removes, measured by a static calorimeter, grows as $(\delta r)^{-2}$ in the radial coordinate toward the horizon (singular in the free-fall frame), cut off at the healing length. The construction is kinematic and does not resolve the information paradox; it yields one concrete, falsifiable prediction: a differential
phonon-calorimetry signal $\mathcal{R}(\delta r)=|\Delta\mathcal{E}|/\mathcal{E}^{(0)}\to(\ell_\kappa/\delta r)^{2}$, present only after the analogue Page time in a Bose-Einstein condensate.
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All authors Nikolay S. Akintsov, Artyom P. Nevecheria, Stepan N. Andreev, Qing-Hua Qin
Fluid Dynamics
Dynamics of a microroller under confinement
Han Gao, Nan Xie, Zaiyi Shen et al. (+3 more)
Rotating particles can translate when placed near a surface, forming microrollers with a wide range of biomedical and microfluidic applications. In this work, we investigate the dynamics of microrollers in confined microchannels with different geometries by combining experiments, numerical simulations, and scaling analysis. In constricted channels, we find that the translational velocity of a microroller decreases as it approaches the constricted region. In both rectangular and cylindrical channels, velocity reversal occurs as the characteristic channel width decreases. Using the force-free condition for free translation, we develop a systematic scaling framework that can be generalized to different channel geometries. The scaling analysis yields functional dependences of the translational velocity on the degree of confinement, which agree well with both experiments and simulations. Importantly, we demonstrate that the viscous stress generated by the far-field rotlet flow governs the observed velocity reduction and reversal, while the translational resistance resulting from the near-field shear flow suppresses translation under tight confinement. The distinct roles of these flow components revealed by our analysis may provide practical guidance for controlling microroller dynamics in confined fluid environments.
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All authors Han Gao, Nan Xie, Zaiyi Shen, Xiaoping Hu, Shiyuan Hu, Ye Xu
Instrumentation and Methods for Astrophysics
Update on the Magellan InfraRed Multi-Object Spectrograph (MIRMOS)
Maren Cosens, Nicholas P. Konidaris II, Gwen C. Rudie et al. (+21 more)
The Magellan InfraRed Multi-Object Spectrograph (MIRMOS) will be a next generation multi-object (MOS) and integral field spectrograph (IFS) for the 6.5m Magellan
telescopes at Las Campanas Observatory in Chile. MIRMOS will perform R~3700 spectroscopy over a simultaneous wavelength range of 0.886-2.404um (Y, J, H, and K bands) in addition to imaging over the range of 0.7-0.886um. Target selection in the MOS mode is achieved through a cryogenic mechanism capable of making up to 92 slits over a 13'x3' field of view (FoV). This mechanism can be reconfigured in real time to adjust slit widths for seeing conditions, change to a different mask, or form a long slit. The IFS mode of operation for MIRMOS will be achieved via an image slicer style integral field unit (IFU) which will provide an ~18"x26" FoV made up of 0.84"x26" slices. MIRMOS's design will allow it to address a wide range of science cases from performing spectroscopy of high-
redshift galaxies as well as high signal-to-noise transmission spectroscopy of
exoplanet atmospheres with the MOS/long slit mode, while also having the largest FoV IFS operating on a large
telescope at these wavelengths. We will describe here the design of the MIRMOS instrument – now at the end of the preliminary design phase.
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All authors Maren Cosens, Nicholas P. Konidaris II, Gwen C. Rudie, Andrew B. Newman, Leon Aslan, Robert Barkhouser, Christoph Birk, Julia Brady, Mathias Gumy, Tyson Hare, Stephen C. Hope, Charlie Hull, Karim Kaismoune, Daniel D. Kelson, Gerrad Killion, Alicia Lanz, Jocob McCloskey, Solange V. Ramirez, Cyril Rupf, William Schoenell, Patricio Schurter, Stephen A. Smee, Peter Spanoudakis, Jason E. Williams
Instrumentation and Methods for Astrophysics
Update on the slicer IFU for the Magellan InfraRed Multi-Object Spectrograph (MIRMOS)
Maren Cosens, Patricio Schurter, Nicholas P. Konidaris et al. (+18 more)
The Magellan InfraRed Multi-Object Spectrograph (MIRMOS) is a planned next generation multi-object and integral field spectrograph for the 6.5m Magellan
telescopes at Las Campanas Observatory in Chile. MIRMOS will perform $\rm R\sim3700$ spectroscopy over a simultaneous wavelength range of 0.886 - 2.404um (Y, J, H, K bands) in addition to imaging over the range of 0.7 - 0.886um. The integral field mode of operation for MIRMOS will be achieved via an image slicer style integral field unit (IFU) located on a linear stage to facilitate movement into the beam during use or storage while operating in multi-object mode. The IFU will provide an $\rm\sim18''\times26''$ field of view (FoV) made up of $\rm0.84''\times26''$ slices. This will be the largest FoV IFS operating at these wavelengths from either the ground or space, making MIRMOS an ideal instrument for a wide range of science cases including studying the high
redshift circumgalactic medium and emission line tracers from ionized and molecular gas in nearby
galaxies. We present here an update on the IFU design from our 2024 proceeding. Previously we utilized a re-imaging style slicer which required freeform pupil mirrors in order to achieve the required image quality while obeying significant packaging constraints near the instrument focal surface. In order to reduce the manufacturing cost and decouple the IFU from the configurable slit unit used in multi-object mode, we have moved the IFU deeper into the instrument, allowing for a switch to a virtual style IFU. This now requires a re-imaging doublet before the slicer mirrors, but removes the need for any freeform surfaces. We present here the optical design and predicted performance of the new MIRMOS IFU along with a conceptual design for the opto-mechanical system which will move the IFU between its active and stored positions.
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All authors Maren Cosens, Patricio Schurter, Nicholas P. Konidaris, Gwen C. Rudie, Andrew B. Newman, Leon Aslan, Robert Barkhouser, Christoph Birk, Julia Brady, Tyson Hare, Stephen C. Hope, Charlie Hull, Karim Kaismoune, Daniel D. Kelson, Gerrad Killion, Alicia Lanz, Jacob McCloskey, Solange V. Ramirez, William Schoenell, Stephen A. Smee, Jason E. Williams
Solar and Stellar Astrophysics
Observational Evidence for Counter-helicity Magnetic Reconnection in a Solar Eruption
Jinrui Chang, Yi Bi, Bo Yang et al. (+3 more)
Magnetic reconnection between coronal
magnetic systems carrying opposite self-helicity may play a role in
solar eruptions, but observational evidence remains limited. We investigate an M7.0
flare in NOAA Active Region 13615 on 2024 March 28 using multiwavelength observations and nonlinear force-free field extrapolations. The reconstructed coronal field reveals a low-lying positive-helicity core field beneath an overlying
magnetic system of opposite sign. During the eruption, the footpoint connectivity of these two
magnetic systems changes markedly: field lines rooted in the western footpoint region change from positive to negative helicity, and the positive-helicity domain is substantially reduced. These changes are accompanied by a remote chromospheric brightening, intermittent EUV stripe-like brightenings extending from the source region toward the remote chromospheric brightening, the subsequent formation of large-scale coronal loops, and a weak outer hard X-ray source located at a footpoint of the core field. Together, these results suggest that the eruption was closely associated with reconnection between the core field and the overlying counter-helicity system, providing observational evidence that counter-helicity reconnection can contribute to the destabilization of eruptive
solar magnetic fields.
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All authors Jinrui Chang, Yi Bi, Bo Yang, Junchao Hong, Jiayan Yang, Qingmei Wang
High Energy Physics (Theory)
Negative shocks versus static patch holography
Yiming Chen, Douglas Stanford, Haifeng Tang et al. (+1 more)
We study a version of de Sitter static patch holography in which the Euclidean gravitational path integral, with an observer worldline included, is conjectured to compute a trace. Motivated by recent evidence for this
conjecture from the sphere path integral, we test it further by inserting operators along the observer worldline and computing two-point functions and out-of-time-ordered four-point correlators (OTOCs). We extend an earlier OTOC calculation by Kolchmeyer and Liu using the shockwave formalism, incorporating both observer
recoil and gravitational backreaction. We find that the OTOC conflicts with two basic properties of a trace in a
Hilbert space: cyclicity and positivity. The signaling feature of the shockwave geometry gives rise to two distinct resummations of the perturbative eikonal expansion, which are interchanged by cyclicity. Positivity is violated by the fact that the leading perturbative contribution causes the (regularized) OTOC to increase.
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All authors Yiming Chen, Douglas Stanford, Haifeng Tang, Zhenbin Yang
Nuclear Theory
Beyond Constant Error: Heteroscedastic Bayesian Model Combination for Modeling Unmeasured Nuclei
B. Knight, S. Lalit, P. Giuliani et al. (+4 more)
Experimentally inaccessible regions of the
nuclear chart remain a challenge for global models of atomic
nuclei to predict. This includes exotic
nuclei near particle drip lines, superheavy elements at the extremes of mass and charge, and the
neutron-rich pathways of astrophysical processes in explosive
stellar environments where heavy elements are created. Given that individual
nuclear models are imperfect, deep extrapolations are best approached using model ensembles, which allow for the systematic combination of diverse theoretical predictions. In this study, we employ the recently introduced
Bayesian Model Combination (BMC) method, based on statistical machine learning, that provides robust uncertainty quantification for forecasts using model ensembles. To account for the inherent degradation of predictive power as models extrapolate into the yet-unexplored domain, we introduce a heteroscedastic BMC framework in which the combined theoretical uncertainty is treated as a dynamic quantity. We apply this methodology to an ensemble of realistic energy density functionals with a specific focus on the $Z=46\text{--}52$ isotopic chains. We rigorously validate the approach using both experimental data and synthetic data designed to assess performance in the deep extrapolation regime. Our results demonstrate that the proposed heteroscedastic approach yields superior calibration metrics and provides statistically principled assessments of the particle drip lines.
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All authors B. Knight, S. Lalit, P. Giuliani, K. Godbey, W. Nazarewicz, A. Ravlić, P. -G. Reinhard
Cosmology and Nongalactic Astrophysics
Supermagnified Stars in Lensing Clusters and Small-Scale Structure in the Dark Matter
Gabriel Torralba and Jordi Miralda-Escudé
Supermagnified
stars, discovered by HST and JWST in
lensing clusters of
galaxies, are luminous
stars in source
galaxies lying near
lensing caustics that are magnified by large factors ($\sim 1000$), making them detectable at cosmological distances. Intracluster
stars in the lens modify the large-scale caustic into a corrugated network of micro-caustics, causing frequent microlensing events of the supermagnified
stars. The frequency and lightcurves of these micro-caustic crossings are extremely sensitive to any small-scale, low amplitude surface density fluctations in the
lensing cluster, making them a unique probe to dark matter minihalos or any small-scale irregularities. Furthermore, the disks of supermagnified
stars can be resolved (at cosmological distances!) from photometric monitoring of micro-caustic crossing events, exploiting the limb darkening effect. Examples are shown of model lightcurves to fit the Kelly et al. (2018) observations of the first supermagnified
star discovered. The unique sensitivity and angular resolution of the Habitable Worlds Observatory enables photometry of microlensing events of supermagnified
stars sensitive to small-scale structure different from intracluster
stars, a probe to the nature of dark matter that is not accessible to other observations at present.
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Mesoscale and Nanoscale Physics
Electric field controlled spin transport in a topological insulator interfaced with a ferroelectric antiferromagnet
Yogesh Kumar, Pushpendra Gupta, Xinyan Li et al. (+14 more)
Topological
insulators have been explored extensively for
spin-charge interconversion via
magnetic interfaces, yet the true response of their
spin-charge conversion, particularly in the absence of an external
magnetic field, remains to be studied. Here, we report electric-field control of
spin-charge conversion in the topological
insulator Bi$_2$Te$_3$ with the
antiferromagnetic multiferroic BiFeO$_3$, employing a nonlocal
spin transport device. A systematic thickness dependence of the
spin transport across the interface between Bi$_2$Te$_3$ and BiFeO$_3$ reveals a signature of topological surface-state-dominated
spin transport in the
bilayer system. The
spin-charge conversion remains robust for thicknesses above 10 nm but falls rapidly with reducing thickness and vanishes at 5 nm. This is consistent with the hybridization-induced emergence of a trivial insulating phase, which is supported by the coherency factor estimated from the magnetoconductance of Bi$_2$Te$_3$. These results establish that
spin-momentum-locked surface states dominate interfacial
spin transport in the decoupled regime. Beyond presenting efficient
spin-charge interconversion at an entirely insulating
magnetic interface, this work also highlights sputter-deposited Bi$_2$Te$_3$ as a high-quality and scalable platform for integrating
quantum materials into devices. The nonlocal
spin transport approach presented here provides a simple and direct evidence of
spin-charge conversion and opens an efficient and practical pathway toward designing energy-efficient
spin-based devices.
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All authors Yogesh Kumar, Pushpendra Gupta, Xinyan Li, Richa Mudgal, Ashish Omar, Ryan Chen, Mito Funatsu, Maya Ramesh, Nicholas Reiterer, Yuanqi Lyu, Yiping Zeng, Darrell G. Schlom, Alessandra Lanzara, Robert J. Birgeneau, James G. Analytis, Ramamoorthy Ramesh, Sajid Husain
Strongly Correlated Electrons
Terahertz Lattice Imprint of a Hidden Multipolar Ordering Transition in Gd$_2$Ru$_2$O$_7$
Nicolas M. Kawahala, Rafael L. Sabainsk, Esteban Marulanda et al. (+2 more)
Magnetic order carried by higher-rank multipoles produces no net moment and couples only weakly to conventional dipolar probes. Recently, the
lattice has been proposed as an alternative detection channel for the associated ordering transitions. Here we report magneto-terahertz time-domain spectroscopy of the pyrochlore ruthenate Gd$_2$Ru$_2$O$_7$, in which a single spectrum resolves an exchange-split Gd$^{3+}$ transition and an infrared-active optical
phonon. The temperature and field dependence of the
magnetic mode give two independent determinations of the internal exchange field at the rare-earth site, which yield a magnitude of 5-6 T and a free-ion $g$-factor. The optical
phonon, sensitive to
spin-disorder scattering rather than to the static exchange field, exhibits a sharp anomaly in frequency and lifetime at 10 K that shifts to 30 K under 7 T, which we identify as an ordering transition of the Gd sublattice hidden from bulk thermodynamic probes. These results identify
spin-
phonon coupling as a route to rare-earth ordering transitions in multipolar magnets, one that is applicable to polycrystalline samples.
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All authors Nicolas M. Kawahala, Rafael L. Sabainsk, Esteban Marulanda, Rafael S. Freitas, Felix G. G. Hernandez
Materials Science
The WEST code for large-scale excited-state materials simulations
Victor Wen-zhe Yu, Siyuan Chen, Yu Jin et al. (+5 more)
We present WEST, an open-source plane-wave pseudopotential code for large-scale excited-state materials simulations, and describe its theoretical foundations, software architecture, and capabilities. WEST implements full-frequency GW,
quantum defect
embedding theory, the Bethe-Salpeter equation, and time-dependent density functional theory within a common algorithmic framework that avoids the explicit computation of virtual electronic states. By combining density functional and density
matrix perturbation theory, low-rank representations of the dielectric screening and exact exchange, and localization techniques, WEST achieves favorable computational scaling with system size. The code supports the calculation of quasi-particle and neutral excitation energies, optical and photoluminescence spectra, excited-state forces, and non-adiabatic couplings, with interoperable workflows connecting to
quantum chemistry, vibronic coupling, and
quantum computing packages. A hierarchical parallelization strategy and GPU acceleration deliver near-ideal strong scaling to thousands of GPUs, enabling accurate excited-state simulations of systems with more than a thousand atoms. Representative applications, spanning the full optical cycle of solid-state
spin defects, self-trapped
excitons in metal-halide perovskites, and the optical response of
liquid water and ice, demonstrate the accuracy and versatility of the code across diverse material classes. The capabilities implemented in WEST establish the code as a scalable platform for predictive excited-state simulations, high-throughput materials discovery, and the generation of high-fidelity
datasets for machine learning in computational materials science.
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All authors Victor Wen-zhe Yu, Siyuan Chen, Yu Jin, Vrindaa Somjit, Stefano Paolo Villani, Jiawei Zhan, Marco Govoni, Giulia Galli
High Energy Physics (Theory)
Resurgent Lambert series from Feynman and beyond
David Broadhurst and Daniele Dorigoni
Lambert series of the form $\sum_{n>0}a(n)q^n/(1-q^n)$ are ubiquitous in mathematical physics. In particular, 2-loop sunrise and 3-loop banana Feynman diagrams yield Lambert series with $a(n)$ of the form $\chi(n)/n^s$ where $\chi(n)$ is a Dirichlet character. Resurgence concerns the singular limit as $|q|$ approaches 1. In the Feynman cases we can control this limit, obtaining rapidly convergent expressions, since the Lambert series are iterated integrals of holomorphic Eisenstein series twisted by a character. We generalize this result, to include modular resurgent structures found in topological-string observables.
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Physics and Society
The Wulff bio-heat transfer model revisited: directional blood enthalpy transport, the biological Peclet number, and implications for laser-induced thermal therapy
Valerio D'Alessandro, Matteo Falone, Luca Giammichele et al. (+1 more)
Bio-heat transfer models play a fundamental role in predicting temperature fields during
laser-induced thermal therapy (LITT). Among continuum bio-heat transfer models, the Pennes equation remains the most widely adopted formulation. However, by representing blood perfusion as an isotropic volumetric source, it neglects the directional transport of thermal energy associated with blood flow. The Wulff model overcomes this limitation by incorporating blood averaged enthalpy transport directly into the heat flux. Despite its physical significance, the derivation of the Wulff formulation and the assumptions required to obtain its governing equation remain only briefly discussed in the original work. The aim of the present work is twofold. First, the physical formulation originally proposed by Wulff is revisited in order to clarify its derivation and the assumptions required to obtain the governing equation. In particular, the physical origin of the modified heat flux is investigated and an equivalent formulation with an independent metabolic source term is discussed. Second, the resulting model is assessed against the classical Pennes formulation through representative
laser-induced thermal therapy
benchmark problem. The numerical results show that accounting for blood flow directionality may substantially alter the predicted temperature field and the extent of thermal damage. A dimensionless analysis further leads to the definition of a biological Peclet number, which quantifies the magnitude of directional blood enthalpy transport relative to thermal
diffusion. Finally, a simple extension accounting for venous stasis is proposed, mitigating the excessive temperature rise predicted by the original Wulff formulation
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All authors Valerio D'Alessandro, Matteo Falone, Luca Giammichele, Renato Ricci
Instrumentation and Methods for Astrophysics
phoptic – a Python package for reducing astronomical images
Zackery A. Irving, Noel Castro Segura, Diego Altamirano et al. (+6 more)
Publicly-available photometry pipelines make astronomical data reduction accessible to non-experts, reduce the margin for human error, and enable reproducible reduction. In many cases, bespoke reduction software is written on a per-instrument basis; this results in rigid pipelines that cannot be straightforwardly applied to data from other instruments. To alleviate this problem, we present phoptic, an open source photometry pipeline written in Python. phoptic began as a dedicated pipeline for the the OPtical TIming CAMera (OPTICAM), a triple-camera system mounted on the 2.1~m
telescope at the Observatorio Astronomico Nacional in San Pedro Martir, Mexico. However, phoptic now serves as a generic photometry pipeline with a simple interface to reduce data from other instruments. At its core, phoptic leverages the astropy Python package, and affiliated packages thereof, to provide a flexible, modern, and interoperable reduction pipeline. In particular, phoptic uses photutils for background estimation, source detection, and performing aperture photometry. Additionally, phoptic implements optimal photometry, improving the signal-to-noise ratio over aperture photometry by up to $\sim 10$ per cent. We describe phoptic's functionality, discuss its default behaviour, and demonstrate its flexible interface by reducing data from the HiPERCAM, MEXMAN, OPTICAM, and ULTRACAM instruments. We also review the performance of phoptic, and show that it is highly scalable on multi-core CPUs.
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All authors Zackery A. Irving, Noel Castro Segura, Diego Altamirano, Federico Vincentelli, Angel Castro, Romina P. Petrucci, Raul Michel, Adam B. Hill, Juan V. Hernandez Santisteban
High Energy Physics (Theory)
Temporal Entanglement from Twist Correlators in 2d Conformal Field Theory and Holography
Alice Bernamonti, Federico Galli, Michal P. Heller et al. (+2 more)
We formulate timelike
entanglement entropy and its Rényi extension in two-dimensional conformal field theory through the analytic continuation of replica twist correlators to time-ordered, timelike-separated insertions. This field-theoretic construction grounds and generalizes recent developments, and applies to temporal subregions of arbitrary extent. Within three-dimensional holography, the semiclassical boundary correlator identifies boundary-anchored complex geodesics as the relevant bulk saddles and selects the one with the smallest real part of the length. This provides a direct boundary derivation of the proposed complex extremal surface prescription and extends to Rényi index $n>1$, for which we explicitly construct the corresponding complex
cosmic brane geometry in the
vacuum. We develop these ideas in several representative settings, including locally and globally excited states and
quantum operator quenches, making manifest the precise agreement between boundary twist correlator and bulk complex geodesic calculations. For AdS-Vaidya, our approach predicts a different result from earlier piecewise geodesic constructions, while reproducing the field theory answer. Across these examples, the operator ordering uniquely determines the imaginary part of the complex-valued
entropy, which is quantized in units of $c\pi/6$ and sensitive to the effective causal structure but not to the underlying dynamics.
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All authors Alice Bernamonti, Federico Galli, Michal P. Heller, Fabio Ori, Alexandre Serantes
Strongly Correlated Electrons
Thermodynamic and electrical transport properties of the half-Heusler plumbide TbAuPb
Abhinav Agarwal, Snehashish Chatterjee, Maciej J. Winiarski et al. (+4 more)
Structural, thermodynamic and electrical transport properties of TbAuPb were investigated on single
crystals. The compound was found to crystallize with the cubic MgAgAs-type structure characteristic of half-Heusler materials. It orders antiferromagnetically at TN = 5 K and undergoes a transition into a different
antiferromagnetic phase emerging in high
magnetic fields. Electrical transport in TbAuPb exhibits a multiband character, with a predominance of hole-like carriers. Angular magnetoresistance evolves systematically with applied
magnetic field and changes its
symmetry near the
spin-reorientation transition, highlighting strong coupling between the charge transport and the
magnetic order. The results of first-principles calculations indicate that TbAuPb is a band inverted semimetal in the non-
magnetic state, which becomes topologically trivial in the field-induced
ferromagnetic state.
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All authors Abhinav Agarwal, Snehashish Chatterjee, Maciej J. Winiarski, Orest Pavlosiuk, Dorota A. Kowalska, Piotr Wisniewski, Dariusz Kaczorowski
Solar and Stellar Astrophysics
The potential broader complex linked to the key Cepheid SV Vul
Daniel Majaess, Ignacio Negueruela, Leonid N. Berdnikov et al. (+10 more)
A new distance was established to the Cepheid SV Vul ($P\simeq45^{d}$) and its host cluster Alicante 13, and is tied in part to deeper UKIDSS-DR6 photometry and
Gaia DR3 observations ($d=2.30\pm0.13$ kpc). SV Vul and Alicante 13 possibly belong to a broader coeval
stellar complex, which could include Liu-Pang 1738. The clusters and Cepheid share comparable astrometry (e.g., $\sigma_\pi\simeq0.02$ mas, $\sigma_{\mu_\delta}\simeq0.06$ mas yr$^{-1}$), and similar cluster turnoffs (ages) exist as indicated by ultraviolet UVEX color-color analyses,
Gaia XP spectroscopically differentially dereddened color-magnitude diagrams, and Padova isochrones. Yet SV Vul may be comparatively overluminous. Robust radial velocities for both clusters could substantiate certain hypotheses.
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All authors Daniel Majaess, Ignacio Negueruela, Leonid N. Berdnikov, Charles J. Bonatto, David G. Turner, Dante Minniti, Vittorio F. Braga, Giovanni Carraro, Igor Usenko, Giuseppe Bono, Matias Gomez, Roberto K. Saito, Maria G. Navarro
Disordered Systems and Neural Networks · Cross-listed from q-bio.NC
Activity Regeneration from Silent States in Neuronal Networks with Transient Synaptic Memory
Mozhgan Khanjanianpak and Alireza Valiadeh
Transient synaptic
memory has emerged as a potential mechanism for maintaining short-term information even in the absence of persistent neuronal activity. However, it remains unclear whether the hidden synaptic state alone contains sufficient information to predict the future
evolution of neuronal networks after activity has ceased. Here, we introduce a minimal neuronal network model with finite-lifetime synapses and investigate the mechanism underlying spontaneous activity regeneration following complete neuronal silence. We show that the residual synaptic configuration at the first silent state already determines whether network activity terminates after a single activation cycle or spontaneously regenerates an additional cycle. By analyzing this synaptic-
memory snapshot, we identify the Latent Excitatory Recruitment (LER) capacity, quantified by the cumulative number of fresh excitatory
neurons, as a near-perfect predictor of multi-cycle dynamics without continuing the subsequent network simulation. Remarkably, these distinct dynamical outcomes emerge in an otherwise homogeneous neuronal network, demonstrating that transient synaptic
memory alone is sufficient to generate diverse future dynamics. Our findings provide a mechanistic explanation for activity regeneration from a residual synaptic state and suggest that short-term
memory is encoded not only in ongoing neuronal activity but also in the latent synaptic configuration that preserves the network's capacity to recruit new neuronal assemblies. More broadly, the proposed snapshot-based framework offers a new perspective for predicting and potentially controlling the future
evolution of neuronal networks.
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Soft Condensed Matter
Driven Odd Elasticity in Passive Mechanical Metamaterials
Mohamad Rahimi and Harold S Park
We present a mechanical mechanism leveraging passive mechanical components, i.e.
chiral gears and a square
lattice metamaterial, to demonstrate driven odd elasticity in a mechanical metamaterial. The mechanism couples tension and shear in a non-reciprocal way, resulting in an odd shear modulus. The emergence of this odd shear modulus enables non-conservative work in a standard quasistatic strain cycle, and further enables the non-Hermitian skin effect in dynamics. Our results demonstrate that odd elasticity can be achieved in mechanical structures using passive elements without electronic components coupled with feedback or robotic control systems.
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Mathematical Physics
How to Recover Oscillation-Free Pressure in Real Fluids: The RFQC Method and Its Liquid-Upwind Anomaly
Haotong Bai, Yixin Yang, Wenjia Xie et al. (+2 more)
From the perspective of continuum thermodynamics, we revisit the pressure oscillation problem in finite-volume methods for multiphase real fluids and clarify the physical counterpart of the Real Fluid Quasi-Conservative (RFQC) method. The pressure oscillation in conservative finite-volume methods originates from their implicit thermodynamic
equilibrium assumption, whereas recovering an oscillation-free pressure requires additional physical information. The RFQC method achieves this by evolving the affine parameters xi and E0 of the isentropic internal-energy-pressure relation along pathlines, while the thermodynamic re-projection converts the deviation from the isentropic trajectory into an internal-energy error, thereby ensuring the thermodynamic consistency and numerical stability of the method. We then investigate the applicability limit of the RFQC method and identify a
Liquid-upwind Anomaly (LUA) in extreme phase-change cases. For a Riemann problem involving
liquid-vapor phase change, a numerical anomaly may occur if a
liquid-upwind translational velocity is initially superimposed. Theoretical analysis reveals that this anomaly is initiated by the jump in the affine slope xi during phase change, which delays pressure rise in the downstream vapor
cell. Concurrently, the re-projection removes the positive pressure increment, repeatedly generating large internal-energy errors and trapping the vapor
cell in a cycle of delayed pressure recovery. The analysis indicates that the LUA is a start-up anomaly, which can be resolved by introducing a regularization strategy at the initial discontinuity. With the proposed regularization strategy, the RFQC method is equipped with enhanced accuracy and robustness for extreme thermodynamic flows, such as sonic phase-change jets.
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All authors Haotong Bai, Yixin Yang, Wenjia Xie, Ping Yi, Mingbo Sun
Strongly Correlated Electrons
$\texttt{iNORG}$: An open-source quantum impurity solver package based on the natural orbitals renormalization group
Jia-Ming Wang, Yi-Heng Tian, Yin Chen et al. (+3 more)
In the context of dynamical mean-field theory (DMFT) calculations for strongly correlated electron systems,
quantum impurity solvers play a central computational role in treating correlated
lattice models and realistic materials. Consequently, developing efficient and robust
quantum impurity solvers remains a key challenge. In this paper, we present an open-source
quantum impurity solver package based on the natural orbitals renormalization group (NORG) method, dubbed $\texttt{iNORG}$. This software delivers high accuracy with reduced computational cost by optimizing the bath representation using natural orbitals and incorporating advanced features such as efficient
Hilbert space selection and efficient
algorithms for computing Green's functions. We first introduce the basic principle of the NORG method and then discuss the implementation details. The software framework, major features, and installation procedure for $\texttt{iNORG}$ are explained as well. Finally, several simple examples are presented to demonstrate the usage of $\texttt{iNORG}$.
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All authors Jia-Ming Wang, Yi-Heng Tian, Yin Chen, Ru Zheng, Rong-Qiang He, Zhong-Yi Lu
General Relativity and Quantum Cosmology
Dark matter environments and safeguards for spacetime inference from horizon scale interferometry
Mohsen Fathi
Horizon scale interferometry can test a black hole spacetime only when the data, source model, and numerical response are reliable. We study this requirement with the public 2017 M87* closure data, a frozen semi analytic emission model, explicit dark matter controls, and a rotating
tidal charge deformation. We normalize NFW and Einasto
halos, an adiabatic spike, a capture suppressed spike, and a heated crest for M87*. Even the intentionally optimistic rendered case, $M_{\rm DM}(<10M)/M_{\rm BH}=7.33\times10^{-5}$, changes the normalized image and visibility by only about $2.65\times10^{-6}$ and $4.9\times10^{-7}$. We then build an independent closure phase and log closure amplitude likelihood with covariance and three fixed high/low band correlation cases. Synthetic Kerr tests recover the expected statistic, coverage, and false positive rate. The real data give $\chi^2/N=1.7583$, $1.7206$, and $1.6873$, above the global adequacy limit of $1.5$; the worst band gives $2.0216$. Removing the most influential scan still leaves $\chi^2/N=1.6472$. If
tidal charge is allowed anyway, the residual projects strongly onto it, but the preferred direction changes sign between image resolutions. Direct libraries at $N=192$, 224, and 256 also fail the differential response convergence tests. At a smoothing width of $0.5M$, the Kerr image changes by about $0.45\%$ between $N=192$ and 224, while the
tidal charge response changes by about $49\%$. We therefore report no posterior or bound. Spacetime inference should remain closed until the adopted data and covariance are validated, the undeformed source passes an absolute adequacy test, and the differential metric response converges independently of the image.
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High Energy Astrophysical Phenomena
The Origin of Multi-TeV Gamma-rays in LHAASO J0341+5258 via Cosmic Ray Illumination of Molecular Clouds
Abhijit Roy, Alan Sunny, Martina Cardillo et al. (+2 more)
We investigate the origin of the ultra-high-energy $\gamma$-ray emission detected by the Large High Altitude Air Shower Observatory (LHAASO) from the source LHAASO J0341+5258, which has not yet been associated with any known astrophysical object within the detector's field of view. The observed UHE emission is modelled within two independent frameworks: initially with a time-dependent, source-independent hadronic scenario implemented with the numerical package GAMERA, where particles propagate through the interstellar medium and subsequently interact with the molecular gas observed in the region and finally with an analytical description of the interaction between the accelerated
cosmic-ray population from a
supernova remnant (SNR) and the molecular gas around it. The relevant parameter space for the hypothetical past SNR is explored using the observed TeV $\gamma$-rays. We show that, for physically plausible source-cloud separations and propagation timescales, GAMERA provides a first-order approximation to the spectral modifications induced by particle transport and yields an adequate fit to the ultra-high-energy $\gamma$-ray data. Within the framework of our analytical approach, we demonstrated that the observed GeV emission can plausibly originate from the SNR itself, while the TeV emission detected by LHAASO can be consistently interpreted as arising from particles that have escaped from the SNR and are illuminating nearby molecular clouds. We invoke a spatio-temporally evolved SNR-molecular cloud interaction scenario to account self-consistently for the entire $\gamma$-ray spectrum from GeV to TeV energies. Despite the remaining uncertainty regarding the nature of the acceleration source, we conclude that the TeV emission detected by LHAASO can be consistently interpreted within the framework of an illumination scenario.
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All authors Abhijit Roy, Alan Sunny, Martina Cardillo, Jagdish C. Joshi, Ritabrata Sarkar
Quantum Physics
Nonreciprocal Relaxation Acceleration
Xingyu Zhang, Yihan Ma, Yue Liu et al. (+5 more)
Driven by recent discoveries regarding the
quantum Mpemba effect, the anomalous relaxation dynamics of open
quantum systems have garnered significant
attention. While expediting thermalization to
equilibrium has been extensively studied, dynamically accelerating the convergence toward nonequilibrium steady states remains a formidable challenge. In this article, we find a transient engineered nonreciprocal dissipative channel can provide a shortcut that accelerates convergence to the target reciprocal nonequilibrium steady state for the considered two-mode model and initial states. Using interacting bosonic modes, we demonstrate that the temporal activation of a nonreciprocal channel efficiently suppresses prolonged inter-mode energy oscillations, enforcing a rapid, unidirectional thermal dump into the environment. Counterintuitively, we find that this relaxation speedup is robust and independent of the direction of the nonreciprocity. Our results provide a powerful thermodynamic technique for rapid state preparation and cooling in continuous-variable
quantum systems, particularly critical for low-temperature
quantum information processing.
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All authors Xingyu Zhang, Yihan Ma, Yue Liu, Niaz Ali Khan, Chenlong Huang, Yuguo Su, Junyan Luo, Dahai He
Optics
Magneto-optical hologram lens with microsecond focal switching in magnetic garnet
Hibiki Miyashita, Toshiaki Watanabe, Eri Negishi et al. (+3 more)
Active lenses based on metasurfaces have been demonstrated across broad applications, and their response speeds remain limited to the microsecond range. Here we report the experimental demonstration of a magneto-optical (MO) active lens based on a
magnetic hologram formed on a
magnetic garnet film. A Fresnel zone plate pattern was created using an array of permanent magnets, focusing a 633 nm
laser beam of 12.5 mm diameter to a spot size of 0.7 mm at a focal length of 3.1 m with a modulation depth of ~91%. The focusing state was reversibly switched by applying an external
magnetic field pulse. Through optimization of the
magnetic field application system, a switching speed of 10.8 $\mu$s was achieved, surpassing the operating speeds of conventional active lenses. The intrinsic picosecond-scale response of the MO effect indicates that further improvement in switching speed is achievable, establishing this work as a proof-of-concept for ultra-fast active lenses.
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All authors Hibiki Miyashita, Toshiaki Watanabe, Eri Negishi, Mitsuteru Inoue, Kazushi Ishiyama, Taichi Goto
Quantum Gases
Dipolar mixtures in checker-board optical bilayers
Rukmani Bai and Luis Santos
Ultra-cold dipolar mixtures in component-dependent optical potentials constitute an interesting platform for the study of the interplay between intra- and inter-component anisotropic long-range interactions. We study the particular case of binary dipolar mixtures placed in separated
bilayers which are displaced in an anti-magic wavelength configuration. Using a combination of second-order perturbation theory and cluster-Gutzwiller calculations, we unveil a rich landscape of possible crystalline phases for the two components, showing that, interestingly, inter-site hopping may result, via super-exchange, in solid-into-solid transitions between different crystalline phases. These crystalline phases and the corresponding transitions can be experimentally realized using e.g. lanthanide mixtures in optical
lattices.
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