Solar and Stellar Astrophysics
Stellar Forcing of (exo)Planetary Environments
Julián D. Alvarado-Gómez, Erika Palmerio, Manuel Güdel et al. (+13 more)
The environments of
exoplanets are fundamentally shaped by the
magnetic activity of their host
stars through radiative,
plasma, and particle-driven processes. This article presents a comprehensive overview of the four principal forms of
stellar forcing that regulate atmospheric structure, chemistry, escape, and long-term planetary
evolution: high-energy radiation, magnetized
stellar winds, coronal mass ejections, and energetic particles. Using the Sun as a physically resolved
benchmark, the discussion extends to increasingly active cool
stars to establish a broader picture of
star–
planet interactions across the main sequence. The article first examines
stellar X-ray and extreme ultraviolet emission from chromospheres and coronae, together with variability introduced by
flares and
magnetic reconnection. Particular
attention is given to spectroscopic diagnostics, activity scalings with
stellar rotation and age,
flare energetics, and the observational links between impulsive and gradual phases of
magnetic energy release. The treatment then shifts to magnetized
stellar winds, describing the mechanisms that drive them and the role of multidimensional magnetohydrodynamic modeling in determining wind structure, angular momentum loss, and planetary interaction regimes.
Solar and
stellar coronal mass ejections are explored through their diagnostics,
flare associations, propagation, and possible suppression by strong
stellar magnetic fields. Finally,
galactic and
stellar energetic particles are discussed together with methods for estimating particle environments and their consequences for atmospheric chemistry and
climate. The article concludes by outlining future observational and numerical developments needed to connect these coupled
stellar forcing processes within a unified exoplanetary framework.
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All authors Julián D. Alvarado-Gómez, Erika Palmerio, Manuel Güdel, Kosuke Namekata, Konstantin Herbst, N. Eugene Engelbrecht, Antoine Strugarek, Judy J. Chebly, Astrid Veronig, Maria D. Kazachenko, Krisztián Vida, Kristina G. Kislyakova, Katja Poppenhäger, Antonio García-Muñoz, Yuta Notsu, Harish K. Vedantham
High Energy Physics (Phenomenology)
HyperFORM – a FORM package for parametric integration with hyperlogarithms
Adam Kardos, Sven-Olaf Moch and Oliver Schnetz
HyperFORM brings the parametric integration of hyperlogarithms, weighted by rational prefactors, into the symbolic-manipulation system FORM. It ports the capabilities of Erik Panzer's Maple package HyperInt, capitalizing on FORM's speed with bulky algebraic input and on its ability to spread a single calculation across many processor cores. We keep the description of the method brief and concentrate instead on how the package is organized and driven: a fully self-contained program for the three-loop zigzag period serves as a worked illustration, and timing measurements for zigzags through six loops gauge its present reach. HyperFORM is released openly and applies to a broad class of problems, the evaluation of Feynman integrals prominently among them.
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Materials Science
Electric-field effects on defect migration energetics in GaN
Farshid Reza, Hamdy Arkoub, Alexander S. Hauck et al. (+2 more)
A predictive understanding of defect transport in GaN under operating electric fields is critical for assessing device reliability in high-power and radiation environments. In this work, a ReaxFF reactive force field for GaN is developed using a density-functional-theory training set that includes structural, thermodynamic, and defect properties. The force field yields various properties such as
lattice parameters, cohesive energies, and defect formation and migration energies in close agreement with prior first-principles and experimental results. Under externally applied electric fields, we find that migration barriers can be strongly modulated, with changes that depend on defect type and field orientation. Notably, the electric fields do not simply linearly bias defect motion in GaN, but can anisotropically modify migration barriers through charge-
lattice coupling, leading to nonlinear transport behavior. The response arises from field-induced partial charge redistribution and local
lattice distortion. These results demonstrate that electric fields can complexly modify the defect migration landscape, providing new insight into defect transport in GaN under high-field conditions.
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All authors Farshid Reza, Hamdy Arkoub, Alexander S. Hauck, Adri C.T. van Duin, Miaomiao Jin
Quantum Physics
Continuous Observation of Quantum Systems
Hans Maassen
In a series of papers in the 1980's Alexander Holevo proved a classification
theorem for continuous
quantum measurement processes, or, as they would today be called, stationary
quantum trajectories in continuous time. His main tools were functional analytic in character: starting from a Bochner-type inequality he employed dilation techniques for positive definite kernels. Here we give an alternative, more probabilistic proof: we use weak convergence of measures and employ Levy's Continuity
Theorem. We clarify the boundedness conditions in Holevo's
theorem, and supply a simple example from
quantum optics.
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Fluid Dynamics
Objective kinetic theory for FENE dumbbell suspension
Liviu Iulian Palade and Alan Jeffrey Giacomin
The novelty of this work is that it takes a result of macromolecular theory that is not objective, and fixes it. To do so we use an objective vorticity tensor to obtain a fully frame invariant form of the classical constitutive equation for FENE dumbbell fluids obtained within the conceptual framework of kinetic theory for
polymer solutions. The influence of such an objective formulation is discussed for steady shear flows.
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Computational Physics
Verification of a sequential thermo-poroelasticity formulation in PFLOTRAN
J. Al Kubaisy, G. E. Hammond, S. Karra et al. (+4 more)
We present the verification of a thermo–hydrologic–mechanical capability implemented within the PFLOTRAN framework, with emphasis on
benchmark-based assessment of the THM implementation. The thermal–hydrologic (TH) equations for mass and energy balance are solved on control-volume blocks or Voronoi
cells, while the quasi-static momentum balance is solved on an element-based dual mesh. The coupling is achieved using a strictly sequential, non-iterative fixed-stress split strategy in which the TH system is solved implicitly for pressure and temperature, followed by a mechanics update for the displacement unknowns. Several verification problems are set up against poroelastic and thermo-poroelastic
benchmarks, demonstrating agreement with analytical or semi-analytical
benchmark responses for pressure
diffusion, the temperature field, and mechanical deformation. In addition, we propose a treatment for discontinuities (e.g., fractures) based on mapping between mechanical and flow degrees of freedom, and validate the approach by comparison to an analytical solution. This work establishes the basis for thermo-poroelastic coupling in PFLOTRAN and provides a solid modeling foundation for a range of applications (e.g., enhanced geothermal systems and other subsurface energy storage) involving coupled thermal–hydrologic–mechanical (THM) processes in geologic porous media.
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All authors J. Al Kubaisy, G. E. Hammond, S. Karra, J. Burghardt, L. Murdoch, T. Johnson, K. M. Rosso
Astrophysics of Galaxies
Searching for the elusive CH2+ with the James Webb Space Telescope. Another carbocation to constrain astrochemical networks
M. Zannese, L. H. Coudert, E. Dartois et al. (+14 more)
Carbocations are key species in interstellar chemistry, providing entry points for building larger hydrocarbons. CH+, and more recently, CH3+, have been detected. Other carbocations await detection to provide a comprehensive view of the astrochemical network that is at work in the interstellar medium. We search for CH2+ in objects in which CH3+ was detected and evaluate the most favorable conditions for detecting the elusive CH2+ reactive cation. We calculated the CH2+ rotational and rovibrational transitions expected to contribute in the mid- to far-infrared, focusing on the lower-energy rovibrational levels. We then calculated CH2+ infrared emission spectra at different excitation temperatures and compared them to JWST spectra of the externally irradiated disk d203-506 in Orion, where CH+ and CH3+ have already been detected. We used thermochemical models to predict the abundance and spatial morphology of CH2+ to better understand its nondetection. The comparison to JWST spectra allowed us to provide excitation-temperature-dependent upper limits to the excited column density. These are several times lower than those detected for CH+ and CH3+ in their excited states. Based on model calculations for photodissociation regions and assuming similar excitation temperatures, the upper limit derived from observations and CH2+ model spectrum is either slightly above or below the column density expected from models of photodissociation regions. We provide a list of tabulated transitions to allow the community to search for this carbocation in future observations as CH2+ is key in providing observational constraints on astrochemical models.
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All authors M. Zannese, L. H. Coudert, E. Dartois, P. Dell'Ova, O. Roncero, P. del Mazo-Sevillano, U. Jacovella, B. Gans, J. R. Goicoechea, D. Van De Putte, C. Boersma, E. Habart, E. Peeters, J. Cami, R. Chown, I. Schroetter, O. Kannavou
Quantum Physics
One cut, two parities: exact Fibonacci charge responses in the golden chain
Yi Liang
We determine the exact cut-charge Born law in the ground state of every periodic
antiferromagnetic golden chain with at least three sites. Its two parity branches retain different information. At even length, the ratio of nontrivial to
vacuum probabilities equals the squared Fibonacci
quantum dimension. The odd
vacuum probability equals the even-branch nontrivial probability times one ground-state Born coordinate, while normalization fixes the complement. Parity selects the positive hoop sector at even length and the complementary sector at odd length. At each length, the corresponding cut projector compresses to a scalar in the even sector or to a non-scalar element of a two-character
algebra in the odd sector. The unchanged measurement rule yields categorical
rigidity at even length and one-coordinate state sensitivity at odd length.
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Instrumentation and Methods for Astrophysics
WST, the wide-field spectroscopic telescope: progress on the design of the instruments
David Lee, Joel Vernet, Elizabeth George et al. (+46 more)
WST, the Wide-field Spectroscopic
Telescope is a proposed new facility that will provide a transformational gain in spectroscopic survey capability over existing facilities. The WST is a 12 metre class
telescope equipped with instrumentation to provide simultaneous observations in both multiple-object spectroscopy and integral field spectroscopy modes. This paper will describe the status of the instruments being designed for the WST, the fibre positioner module, the low and high-resolution multiple object spectrographs, the integral field spectrograph, disperser technology, sustainable detector and cryostat technology, and the calibration system. An overview of the overall layout of the instruments within the WST facility will be provided.
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All authors David Lee, Joel Vernet, Elizabeth George, Omar Sqalli, Olaf Iwert, Alessandro Meoli, Vincenzo Mainieri, Philippe Dierickx, Alexandre Jeanneau, Corentin Cudennec, Paolo Franzetti, Olga Bellido, Roelof de Jong, Andreas Kelz, Aaron Omadutt, Steve Watson, Younes Chahid, Chris Waring, Laura Gibbs, Anmol Goyal, Dave Melotte, Lawrence Bissell, Jay Stephan, Oscar Gonzalaez, Sebastien Pernecker, Maxime Rombach, Malak Galal, Jonathan Wei, Jean-Paul Kneib, Joseph W. Barrow, Jon Lawrence, Will Saunders, Dimitri Buffat, Kjetil Dohlen, Andrea Tozzi, Anna Brucalassi, Simone DAuria, Sofia Randich, Matteo Munari, Andrea Bianco, Christophe Yeche, Christophe Magneville, Etienne Burtin, Thomas Augusteijn, Jan Kragt, Ramon Navarro, Julia Bryant, Laurane Freour, Roland Bacon
Materials Science
Topological Hall effect due to electron-skyrmion scattering
Arijit Mandal, Hareram Swain, B. R. K. Nanda et al. (+1 more)
Electron scattering from
chiral spin textures such as skyrmions is fundamental to the understanding of transport in more complex systems, including skyrmion
crystals. Most of the previous studies have focused on the weak-coupling regime, where the exchange interaction is small compared with the electron energy. Real materials, however, often lie in the strong-coupling regime, which exhibits qualitatively different behavior. Using the Lippmann-Schwinger equation and Green's function formalism, valid for all coupling strengths, we uncover several new features in the scattering cross section, including Ramsauer-Townsend minima, pronounced intermediate-coupling resonances, and Landau-level resonances for skyrmions with larger winding numbers. These features strongly influence the topological and
spin Hall conductivities, which depend sensitively on the incident electron energy. Our work provides important insights into the
Hall transport in collective
chiral spin textures such as the skyrmion
crystal.
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All authors Arijit Mandal, Hareram Swain, B. R. K. Nanda, S. Satpathy
Strongly Correlated Electrons
Strange Luttinger liquids in a cavity-embedded one-dimensional electronic chain
Danh-Phuong Nguyen, Christophe Mora and Cristiano Ciuti
We study a one-dimensional electronic chain coupled to a homogeneous quantized
vacuum field and electron-electron interactions. In the absence of the latter, we derive a low-energy effective description in the presence of light-matter coupling, which we identify as a strange Luttinger
liquid. Although it retains a formal resemblance to conventional Luttinger
liquid theory, the coupling to the
quantum field qualitatively modifies the low-energy sector and breaks the standard velocity relation underlying Luttinger universality. For finite electron-electron interactions, we recover a phase diagram featuring several phases as a function of interaction strength and hopping amplitude, including a phase hosting Majorana-like zero modes. Using exact diagonalization, we compute observables that characterize the phase boundaries and show that the cavity field significantly shifts them. We also study the fate of Majorana-like states under the influence of the cavity field, highlighting their modification by light-matter coupling. Finally, we investigate whether the strange Luttinger
liquid description identified in the noninteracting regime continues to hold when electron-electron interactions are introduced.
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Quantum Physics
Physical reduced states and continuum characters of the lattice Kramers-Wannier defect
Yi Liang
A non-invertible topological line fixes global defect data but does not select a reduced density
matrix (RDM) in a spatially twisted sector. For the Kramers-Wannier defect of the critical Ising chain, we choose the equal-weight incoherent mixture of the two charge-sector ground states and reduce it to the ordinary full
spin algebra of a complete non-wrapping prefix anchored at the defect endpoint. The finite-size RDM is the convex average of two charge-sector RDMs rather than a sign-zero Gaussian proxy, and an exact descended antiunitary enforces many-body Kramers pairing without determining the
entropy. At fixed prefix, the RDMs converge in trace norm to a common Gaussian state as the circumference grows. Convergence is uniform over all ground-doublet preparations, including coherent pure states. The subsequent large-prefix
entropy limit follows from the odd-even Toeplitz/Fisher-Hartwig endpoint, yielding half the natural logarithm of two above the homogeneous chain. The matched
spin-flip defect has zero excess. The exact joint energy-modified-translation character of the same twisted
Hamiltonian records the finite-size roots and their multiplicities, retains chirality in the marked scaling limit, and, using the standard Ising character identities, resolves the four Virasoro towers of the Ising duality-twisted sector.
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Instrumentation and Methods for Astrophysics
WST, the Wide-field Spectroscopic Telescope: Telescope structure FE analyses
Simone D'Auria, Vincenzo Cianniello, Ciro Del Vecchio et al. (+6 more)
The Altitude Structure of the Wide-field Spectroscopic
Telescope (WST) is designed to support and position both primary and secondary mirrors, made of structural steel. Due to its dimensions, the Altitude Structure is a substantial part of the WST facility, and its weight, performance, and dynamic behavior play a critical role in the functioning of the
Telescope. This paper discusses the iterative process starting from the preliminary structural layout and leading to the optimization of the entire Structure. A Finite Element (FE) model was developed, defining the detailed dimensions and cross sections of each assembly's beams and plates under representative boundary conditions, in order to correctly simulate the operational environment. This model enables accurate estimation of structural weight, mechanical deformations, and stresses, as well as its frequency response for the evaluation of both local and global resonance modes. Based on the initial results obtained using preliminary beam cross sections and shell thickness, several assumptions were formulated to drive the mechanical optimization of the Altitude Structure. The outcome of this work consists of a refined structural configuration and the formulation of the governing design criteria.
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All authors Simone D'Auria, Vincenzo Cianniello, Ciro Del Vecchio, Vincenzo De Caprio, Philippe Dierickx, Gaston Gausachs, Tony Trauvillon, William Sutherland, Olga Bellido
Instrumentation and Methods for Astrophysics
WST, the Wide-field Spectroscopic Telescope: Mechanical Design and FE Analyses for the High Resolution Spectrograph
Simone D'Auria, Andrea Tozzi, Anna Brucalassi et al. (+5 more)
The Wide-field Spectroscopic
Telescope (WST) is a planned 12-meter-class dedicated spectroscopic facility designed to address key scientific challenges through large spectroscopic surveys. This paper presents the current status of Work Package 4.5, which focuses on the High-Resolution Multi-Object Spectrograph (MOS-HR) module for WST. The MOSHR instrument is expected to provide a resolving power of R = 40,000 with a multiplexing capability of about 2,000 targets. The mechanical design activities carried out for the development of the HR spectrograph and for the definition of its optomechanical architecture are described. To account for both the scientific requirements of the spectrograph and the manufacturability constraints associated with such a complex instrument, the mechanical layout has been organized into four larger modules, each containing two sub-modules. Guided by feasibility considerations, such as mechanical performance, available volume, and fabrication and assembly aspects, each sub-module adopts a vertical optical bench configuration with optical elements mounted on both sides. Starting from the baseline optical design, the mechanical configuration has been developed to achieve the required
alignment accuracy, structural stability, and environmental robustness. The workflow includes the translation of the optical prescription into a complete mechanical model, the definition of the main mounting and
alignment interfaces, and preliminary static, modal, and seismic analyses to evaluate performance under operational and survival loads. As an outcome, the proposed design provides architecture that enables preliminary estimates of mass, volume, cost, and mechanical performance in terms of deformation, stress, and modal behavior of the modules.
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All authors Simone D'Auria, Andrea Tozzi, Anna Brucalassi, Matteo Munari, Ciro Del Vecchio, Maria Sofia Randich, Roland Bacon, David Lee
Astrophysics of Galaxies
Tilting at the Turnover: Modeling the Faint-End of the UV Luminosity Function Behind Abell s1063 with JWST
Caio Moreira Goolsby, Christopher J. Conselice, Duncan Austin et al. (+6 more)
We leverage the strong gravitational field of Abell S1063 to identify faint, highly magnified
galaxies using ultra-deep James Webb Space
Telescope (JWST)/NIRCam imaging from the GLIMPSE survey and ancillary Hubble Space
Telescope (HST)/ACS imaging from the Hubble Frontier Fields program. We construct a photometric catalogue of lensed high-
redshift candidates and use these sources to constrain the faint end of the rest-frame UV luminosity function (UVLF) over $z\simeq6$–11. Rather than treating the UVLF turnover ($M_{\rm t}$) as a hard cutoff, we model it as a gradual quadratic suppression and explicitly account for the potential continued contribution of
galaxies beyond the turnover. In a shallow-turnover scenario, up to one-third of the UV luminosity density can arise from sources fainter than $M_{\rm t}$. While we find no direct evidence for a turnover down to $M_{\rm UV}=-13.5$ at $z=6$, our analysis can only confidently exclude weak, medium, and strong turnover models down to $M_{\rm t}=-15.9$, $-15.1$, and $-14.8$, respectively. Across these models, we infer lower limits of the UV luminosity,
star formation density, and the ionization rate as: $\rho_{\rm UV}\geq22\times10^{25}\,{\rm erg\,s^{-1}\,Hz^{-1}\,Mpc^{-3}}$, ${\rm SFRD}\geq25\times10^{-3}\,M_\odot\,{\rm yr^{-1}\,Mpc^{-3}}$, and $\log_{10}(\dot{n}_{\rm ion}/{\rm s^{-1}\,Mpc^{-3}})\geq51.02$. We find that
galaxies fainter than the conventional $M_{\rm UV}=-17$ limit contribute more than half of the UV luminosity density and at least $\sim64\%$ of the ionizing
photons produced by
star-forming
galaxies at $z=6$. Because our turnover model permits a suppressed, but non-zero,
galaxy population beyond $M_{\rm t}$, sources fainter than the turnover remain contributors to both $\rho_{\rm UV}$ and $\dot{n}_{\rm ion}$, emphasizing the need to consider the turnover and its shape during reionization.
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All authors Caio Moreira Goolsby, Christopher J. Conselice, Duncan Austin, Tom Harvey, Jose Diego, Nathan Adams, Julien Marabotto, Jordan D'Silva, Qiong Li
Instrumentation and Detectors
Plenoptic imaging of particle interactions in scintillation detectors
Xiang Dai, Chi-Jui Ho, Kevin Tandi et al. (+9 more)
Accurate 3D localization of radiation interactions in scintillation detectors is essential for
nuclear and particle physics, safeguards, and medical imaging, but remains difficult in light-starved regimes with limited
photon statistics. We present PRISM, a multifocal plenoptic imaging system designed for millimeter-scale 3D position reconstruction in a single-volume scintillator. PRISM uses a multifocal microlens array with diverse focal lengths and high effective numerical aperture to balance
photon collection with spatial and depth encoding. A Cram'er–Rao lower bound analysis shows that the multifocal design improves axial sensitivity over conventional unifocal plenoptic systems under
photon-limited conditions. We build a prototype system, calibrate its optical response with a tunable light source, and form
photon-limited measurements with $\mathcal{O}(100)$ detected
photons. For sparse single-vertex events, we reconstruct interaction locations using an Alternating Descent Conditional Gradient-inspired
algorithm and demonstrate an average 3D localization error of approximately 1 mm. We also provide an initial evaluation of double-vertex events, showing that localization improves as the axial separation between interactions increases. These results demonstrate that multifocal plenoptic imaging can mitigate the traditional trade-off between light collection and spatial resolution, providing a
photon-efficient approach to 3D reconstruction in scintillation detectors and a foundation for future multi-scattering event reconstruction.
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All authors Xiang Dai, Chi-Jui Ho, Kevin Tandi, Chang Lee, Alex Bocchieri, David Parra, Forrest Peterson, Talha Sultan, Felicia Sutanto, Andreas Velten, Jingke Xu, Nicholas Antipa
High Energy Astrophysical Phenomena
Smoking-gun evidence for hierarchical black-hole mergers
Yin-Jie Li, Yuan-Zhu Wang, Shao-Peng Tang et al. (+1 more)
How
stellar-mass black holes grow after their birth is a central open question in astrophysics. Gravitational-wave observations have revealed a subpopulation of coalescing black holes with both high masses and high
spins, but whether these properties arise from hierarchical mergers in dense
stellar environments or from
accretion onto isolated black holes has remained unresolved. Here, using a flexible mixture population model applied to the 259 binary black hole mergers in GWTC-5, we show that the mass function of the high-
spin subpopulation traces, peak by peak, the predicted remnant-mass distribution of the low-
spin,
stellar-collapse-origin subpopulation up to $\sim80\,M_\odot$. This morphological match, quantified by a Bhattacharyya coefficient as high as $\sim0.95$, is naturally expected if the high-
spin black holes are themselves the products of earlier mergers, whereas any alternative scenario would require fine-tuning, thereby providing smoking-gun evidence for hierarchical mergers. In addition, the sharp upper-mass cutoff of the low-
spin subpopulation at $m_{\rm max,1}=54.2^{+7.7}_{-7.2}\,M_\odot$ yields an astrophysical $S$-factor of $S_{300}=151^{+30}_{-26}$~keV~b (68% credible interval) for the $^{12}{\rm C}(\alpha,\gamma)^{16}{\rm O}$ reaction, in agreement with the
benchmark theoretical value. These results establish that the entire observed black-hole population can be accounted for by
stellar collapse followed by dynamical hierarchical assembly, without invoking
primordial black holes.
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All authors Yin-Jie Li, Yuan-Zhu Wang, Shao-Peng Tang, Yi-Zhong Fan
Mathematical Physics · Cross-listed from math.AP
Weak and dissipative solutions for the Hasegawa-Mima equation
Michele Gorini
We consider the Hasegawa-Mima equation in its “Euler-like” velocity form: \[\partial_t(u-\Delta^{-1}u)+(u\cdot\nabla)u-u^\perp\log n_0=0,\] $n_0$ being the time-independent function appearing in the particle count $n=n_0e^{\frac{e\varphi}{T}}$, and $u$ being the drift velocity $\nabla^\perp\varphi=-\nabla\varphi\times\hat z$. Adapting the notion from Lions' book on the Euler equations, we prove the existence of dissipative solutions for this equation for any $L^2$ divergence free initial condition $w\in L^2(D)$, for $D=\mathbb T^2$ and $D\subset\mathbb R^2$ a bounded $\mathcal{C}^1$ domain.
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General Relativity and Quantum Cosmology
Backreaction of stimulated Hawking radiation in an optical analogue
Lorenzo M. Procopio, Raul Aguero-Santacruz, David Bermudez et al. (+1 more)
Hawking radiation - the emission of
quantum particles at the event horizon of a black hole - connects
gravity with
quantum mechanics and thermodynamics; the Bekenstein-Hawking
entropy has been the
benchmark for potential
quantum theories of
gravity. But Hawking radiation has never been observed in astronomy, only in laboratory analogues and the chances of ever observing it in space are astronomically small. The energy of Hawking radiation must come from the gravitational field around the black hole, but how field quanta generate Hawking quanta has been unknown. Here we report on experimental and theoretical evidence for the process that generates Hawking radiation in a fibre-optical analogue of the event horizon. There, as in
gravity, it has been believed that Hawking radiation comes from a complicated, cascaded process; here we have found a simple, direct process and measured its backreaction on the field. Our findings suggest an equally direct process for other laboratory analogues and perhaps also for gravitational fields, shedding light on how black holes might radiate.
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All authors Lorenzo M. Procopio, Raul Aguero-Santacruz, David Bermudez, Ulf Leonhardt
Lattice Field Theory
Inclusive $\bar B_s\mapsto X_{\bar sc} \ell \bar \nu$ decays from lattice QCD: computational strategy and a first physical result
Alessandro De Santis, Antonio Evangelista, Gael Finauri et al. (+16 more)
We present a strategy to compute the inclusive decay rate for the process $\bar B_s \mapsto X_{\bar sc} \ell \bar{\nu}$ from first principles in
lattice QCD. The physical decay rate is obtained from the interpolation of non-perturbative
lattice data, obtained at lighter than physical heavy
meson masses ($M_{\bar B_s}^\mathrm{max}=4.3$GeV), with the Operator Product Expansion predictions, which become exact in the limit of infinitely heavy
quarks. We also present a new method for the computation of the required
lattice four-point correlators, which represents a considerable improvement over the state-of-the-art on the subject. We show the effectiveness of the strategy by performing the calculation on a subset of the available $n_f=2+1+1$ physical-point Extended Twisted Mass Collaboration (ETMC) gauge ensembles. Our current determination of the inclusive decay rate has a 7% total error, that is dominated by uncertainties due to the relatively limited configuration ensembles considered herein, and can be significantly reduced in the near future.
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All authors Alessandro De Santis, Antonio Evangelista, Gael Finauri, Roberto Frezzotti, Giuseppe Gagliardi, Paolo Gambino, Marco Garofalo, Christiane Franziska Groß, Bartosz Kostrzewa, Vittorio Lubicz, Lorenzo Maio, Francesca Margari, Marco Panero, Francesco Sanfilippo, Silvano Simula, Antonio Smecca, Javier Suarez Sucunza, Nazario Tantalo, Carsten Urbach
Computational Physics
Lanczos Method for QRPA Strength Functions in Atomic Nuclei
Dong Min Roh, Chao Yang, Jonathan Engel et al. (+1 more)
We present a symmetric Lanczos method for computing charge-changing QRPA strength functions in atomic
nuclei. Starting from the finite-amplitude-method formulation of the QRPA linear-response problem, we derive equivalent spectral representations and, in the real case, a reduced
eigenvalue problem involving the
matrix products $MK$ and $KM$, where $M\equiv A+B$ and $K\equiv A-B$ are formed from the usual QRPA
matrices $A$ and $B$. The resulting formulation enables a
matrix-free Lanczos approximation of the Lorentzian-smeared strength function over a broad energy interval from a single Krylov run, in contrast to conventional frequency-by-frequency response calculations. Numerical tests for $^{112}$Sn and $^{150}$Nd first show that GMRES reproduces the converged iterative FAM strength profiles while requiring fewer iterations. Using GMRES as the frequency-by-frequency reference, we then show that the Lanczos approximation reproduces the same strength profiles with reduced overall cost. These results indicate that symmetric Lanczos projection provides an efficient and accurate approach for QRPA strength-function calculations when spectral information is required over an extended frequency range.
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All authors Dong Min Roh, Chao Yang, Jonathan Engel, Matthew L. Dai
High Energy Physics (Theory)
${\cal N}{=}\,4$ supersymmetric multiparticle systems based on indecomposable multiplets
Sergey Fedoruk, Evgeny Ivanov and Stepan Sidorov
We construct new multiparticle models of $\mathcal{N}=4$ supersymmetric mechanics with
spin degrees of freedom by employing nonlinear indecomposable supermultiplets ${\bf (1,4,3){\supset\hspace{-1.1em}+}(4,4,0)}$. These systems are proper deformations of those associated with the standard irreducible $d=1$, $\mathcal{N}=4$ multiplets. In this way we find a deformation of $\mathcal{N}=4$ supersymmetric U$(2)$-
spin rational Calogero system invariant under $d=1$ superconformal group OSp$(4|2)$. One more deformed model reproduces $\mathcal{N}=4$ supersymmetric U$(2)$-
spin hyperbolic Calogero system, up to a shift of the
Hamiltonian by some U$(1)$ generators.
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Optics
Room temperature valley coherence in monolayer WSe2 mediated by chiral nematic liquid crystal
Hassan Lamsaadi, Andrea Balocchi, Aurélien Cuche et al. (+5 more)
Valley coherence refers to a phase-coherent superposition of inequivalent momentum valleys, in which
quantum information can be encoded in the relative valley phase.
Chiral nematic
liquid crystals, by imposing a flip of the
spin angular momentum upon light reflection, provide an effective photonic environment for optically coupling
excitons of the K and K' valleys in monolayer semiconducting transition-metal dichalcogenides. We experimentally demonstrate that using such
liquid crystal as a substrate, it is possible through nearfield interaction to engineer a room temperature mechanism for inducing the intervalley coupling. Our results show that this approach provides a simple and scalable route toward valleytronic functionalities based on controlled coherent emission from valleys with opposite Berry
curvature.
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All authors Hassan Lamsaadi, Andrea Balocchi, Aurélien Cuche, Hugo Lourenco Martins, Vincent Paillard, Sébastien Weber, Jean Marie Poumirol, Gonzague Agez
Fluid Dynamics
Numerical Study of Compressibility and Velocity Parameter Effects on Spatially Evolving Supersonic Turbulent Shear Layers
M. R. B. Shahadat, Z. Li, F. A. Jaberi et al. (+1 more)
Direct Numerical Simulations (DNS) of a spatially developing supersonic turbulent shear layer are conducted for a range of convective Mach numbers ($M_c$) and velocity parameters ($\lambda$) to examine the effects of compressibility and advection on the growth rate, self-similarity, flow statistics, asymmetry, and entrainment of the layer. At distant downstream locations, self-similarity is attained for all cases. The self-similar region is identified by the collapse of normalized mean streamwise velocity, the constant peak of normalized Reynolds stresses, and the linear growth rate of the shear layer thickness and momentum thickness. Despite significant variations in lower-order and higher-order statistics across different $M_c$ and $\lambda$ values, profiles of all
turbulence quantities examined collapse within the self-similar region using our proposed self-similar scalings. The self-similar forms of continuity, momentum, and energy equations have been formulated, incorporating compressibility and centerline shifts. The self-similar normalized density distribution inside the layer is used to explain the effects of compressibility on various flow statistics, including the far-field cross-stream velocity. The density variation is linked to dissipation effects as revealed by our analysis of the self-similar energy equation. An approximate equation for the cross-stream velocity is developed, and the profiles of cross-stream velocity obtained from this equation show good agreement with the DNS results. A
geometric interpretation of the entrainment ratio is presented, and the approximate equation for the cross-stream velocity is used to provide a general closed-form expression of the entrainment ratio. The entrainment ratio increases with $M_c$ and $\lambda$, favoring excess entrainment on the high-speed side.
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All authors M. R. B. Shahadat, Z. Li, F. A. Jaberi, D. Livescu
Solar and Stellar Astrophysics
Automatic detection of solar filament oscillations I: Multi-scale spectral pipeline
Guillem Castelló, Manuel Luna and Jaume Terradas
Solar filament oscillations provide important diagnostics of prominence
magnetic structure and stability, but their detection in long H\alpha archives has traditionally relied on visual inspection, manually placed slits, and time–distance diagrams. We present an automatic pipeline for detecting spatially coherent filament oscillations in GONG H\alpha image sequences. The method combines image preprocessing and coalignment, deep-learning-based filament detection and
segmentation, multi-scale spatial averaging, Lomb–Scargle spectral analysis, convolutional-neural-network background estimation, empirical calibration of significance thresholds, and clustering of candidate detections in period and space. Only oscillations supported across at least four spatial scales are retained, reducing sensitivity to local pixel-scale intensity fluctuations. The pipeline recovers several events from the manual GONG catalog of Luna et al. (2018), including the 1 January 2014 oscillation with a period of approximately 76 min. Applied to the first two weeks of January 2014, it identifies 91 oscillatory events, compared with 22 non-duplicate events in the corresponding manual catalog, with detected periods ranging from about 20 to 126 min. It also detects previously unreported oscillations, including an event on 13 January 2014 with a period of approximately 86 min that is independently confirmed using a conventional time–distance diagram. These results demonstrate that automated filament
segmentation, multi-scale spectral analysis, and calibrated significance testing can provide a reproducible and scalable alternative to manual slit-based searches. The pipeline substantially increases detection sensitivity while preferentially selecting coherent filament-scale oscillations, enabling future statistical studies over extended GONG intervals and across the
solar cycle.
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Materials Science
Diamond Diode for Extreme Venus Environments
Harshad Surdi, Gabriel Munro-Ludders, Mohamadali Malakoutian et al. (+9 more)
A diamond Schottky PIN diode (SPIND) with the highest reported current density to date of ~116 kA/cm2 is demonstrated carrying a total current of ~1.3 A through a 50 micron wide pseudo-vertical diode structure. The diamond SPIND also provides a maximum power handling capacity of 1.85 MW/cm2 and a low specific on-resistance Ron,S of 0.05 mOhm-cm2 at a forward bias of ~16 V. The diamond
SPIN diode also shows excellent rectification characteristics with a current on-off ratio of ~6e12. An analytical model including thermionic emission and space charge limited current is presented together with Silvaco ATLAS TCAD simulations, to accurately reproduce the experimental J-V characteristics using multiple single trap levels and other physical models emulating a real device. Theoretical analysis from the analytical models in conjunction with ATLAS simulations shows that further improvement in the device turn on voltage and Ron,S can be achieved by reducing the defect density and contact resistance in order to approach the ultimate performance in the Mott-Gurney space charge limited current regime
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All authors Harshad Surdi, Gabriel Munro-Ludders, Mohamadali Malakoutian, Srabanti Chowdhury, Savannah Eisner, Mohamed Fadil Isamotu, Mengyang Yuan, Stephen Goodnick, Franz Koeck, James Lyons, Trevor Thornton, Robert Nemanich
Applied Physics
Fabric Phononic Crystals for Passive Vibration Control
Michael Y Wang, Hridyesh Tewani, Marianne Fairbanks et al. (+2 more)
Weaving patterns in fabrics, traditionally used for aesthetic purposes, present a largely untapped opportunity to create metamaterials that serve as passive layers for sensing, filtering, and signal processing. However, the hierarchical architecture of fabrics makes structural design and wave prediction challenging. Here, we establish fully woven fabrics as phononic
crystals that passively filter and route elastic vibrations. Using double weaving, we integrate a soft cotton weave with stiff woven copper inclusions to form periodic fabric
lattices with engineered dispersion. A multiscale modeling framework that combines homogenization of weave blocks with an effective-property macroscale model enables computationally efficient design of phononic
crystals. Simulations and experiments confirm a pronounced phononic bandgap for out-of-plane vibrations in a finite fabric
crystal, while an equivalent pure cotton weave shows no band suppression in the corresponding frequency range. Building on the same platform, we realize a fully woven higher-order topological
insulator. Modal analysis and transmission measurements reveal in-gap edge states and localized corner states. These results show that phononic bandgaps and topological states can be directly encoded through weaving patterns and material contrast, enabling passive vibration management layers and multifunctional waveguiding fabrics for sensing, haptic interfaces, robotics, and noise mitigation.
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All authors Michael Y Wang, Hridyesh Tewani, Marianne Fairbanks, Pavana Prabhakar, Chu Ma
High Energy Astrophysical Phenomena
Early results from the SVOM Observatory Science program
A. Coleiro, L. Tao, F. Cangemi et al. (+44 more)
We present the organisation and early results from the Observatory Science program of the Space-based multi-band astronomical Variable Objects Monitor (SVOM), based on data collected between July 2024 and December 2025. Although primarily designed for gamma-ray burst studies, SVOM's wide-field, multi-wavelength instruments enable a broad range of high-energy astrophysical investigations. We summarize the execution and performance of the General Program and Target-of-Opportunity observations, and we describe the frameworks used for serendipitous source detection and monitoring with the ECLAIRs coded-mask instrument. Over this period, SVOM carried out more than a thousand pointed observations and detected several hundred non-GRB high-energy sources, mainly X-ray binaries, as well as blazars,
stellar flares, magnetars, and unidentified events. We highlight some key results, including the monitoring of the microquasar Cygnus X-1, the detection of burst oscillations from the Low-Mass X-ray Binary 4U 0614+091, the spectral-state monitoring of Aql X-1, the first SVOM detection of an X-ray blazar
flare from 1ES 1959+650, and observations of a
stellar flare from HD 22468. These results demonstrate SVOM's strong capabilities for time-domain astrophysics beyond its core GRB program.
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All authors A. Coleiro, L. Tao, F. Cangemi, X. Han, M. Brunet, N. Dagoneau, A. Foisseau, A. Goldwurm, S. Guillot, N. Jiang, C. Lachaud, S. Le Stum, P. Maggi, D. Rawat, J. Rodriguez, C.W. Wang, J. Wang, W. Xie, L. Zhang, L. Bouchet, M. Clavel, Z. Feng, O. Godet, D. Götz, D. Li, Z. Li, L. Lin, T. Maiolino, J. Wu, L. Xin, S.L. Xiong, X. Xu, J. Zhang, S.J. Zheng, B. Cordier, J. Wei, S. Basa, A. Claret, F. Daigne, J. Deng, Y.W. Dong, E. W. Liang, Y. Qiu, S. Vergani, C. Wu, B. Zhang, S. N. Zhang
High Energy Astrophysical Phenomena
First Gamma-Ray Burst Observations with SVOM
F. Daigne, D. Turpin, J.-L. Atteia et al. (+34 more)
Following its launch on 22 June 2024, the Space-based multi-band astronomical Variable Objects Monitor (SVOM) successfully completed its flight acceptance, commissioning, and scientific validation phases in early 2025, during which several tens of gamma-ray bursts (GRBs) were detected onboard. Three quarters of these events have also been detected by other satellites, and a quarter are SVOM-only GRBs. In this article, we describe these early GRB observations, with a first description of the SVOM GRB sample that is emerging, and of the level of characterisation already achieved, and with a focus on a few events of particular interest. These early results are very encouraging regarding SVOM's ability to detect and fully characterise (including
prompt emission, afterglow and distance) a wide range of GRBs (classical long GRBs, short GRBs, X-Ray Flashes, etc.) and to enable the use of these extreme high-energy transients as probes of the distant Universe.
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All authors F. Daigne, D. Turpin, J.-L. Atteia, J. Palmerio, L.-P. Xin, S. D. Vergani, B. Zhang, C. Wu, T. Maiolino, B. Schneider, D. Zhao, A. Li, D. Malesani, H.-L. Li, A. Saccardi, M.-G. Bernardini, H. Gao, F. Piron, O. Godet, B.-B. Zhang, Y. Wang, L.-J. Chen, B. Cordier, J.-Y. Wei, S. Basa, A. Claret, A. Coleiro, J.-S. Deng, Y.-W. Dong, D. Götz, X.-H. Han, Y.-L. Qiu, C. Lachaud, E.-W. Liang, J. Wang, S.-L. Xiong, S.-N. Zhang
Quantum Physics
Fisher Glasses: Tail-Certified Quantum Metrology in Quenched Environments
El Mustapha Mansouri and Keigo Arai
Quantum metrological advantage is certified by averaged Fisher responses: contrast, susceptibility, or
quantum Fisher information (QFI). This fails in quenched sensors, where slow environmental variables freeze within a session but vary between repetitions: shallow nitrogen-vacancy (NV) centers, superconducting
qubits with slow two-level fluctuators, and
semiconductor spin qubits in drifting charge noise. They sample session-resolved Fisher geometries, not an averaged channel. Certification conditions on the latent session, projects nuisance directions, inverts to attainable loss, then tail-certifies; this inverse upper-tail loss defines quenched tail-certified information. A no-go
theorem: no averaged Fisher data determine this certificate; ensembles sharing averaged Fisher
matrix, QFI, and projected information have finite or zero certified precision. A Fisher-zero integrability transition governs collapse: the inverse-loss tail exponent $\beta$ sets the boundary, with nonintegrable certified loss for $\beta \le 1$, even when annealed information is large or scaling. The certified
quantum resource is response transverse to latent disorder, not raw amplification sharing its generator; universal design laws: safe windows, nondegenerate portfolios, Fisher reserves, action separation, Fisher-cut criteria. A shallow-NV Ramsey tournament shows average-QFI optimization is tail-catastrophic, whereas tail-certified designs recover nearly three orders of magnitude in certified information at equal shot budget and latent ensemble. These non-self-averaging phases are Fisher glasses, governed by Fisher-zero rare-event statistics.
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