Earth and Planetary Astrophysics
A Homogeneous Survey of JWST MIRI Transmission Spectra of 10 Exoplanets
Martin Binet, Nikku Madhusudhan, Måns Holmberg et al. (+1 more)
The launch of JWST has enabled unprecedented atmospheric characterization of
exoplanets. In particular, the JWST-MIRI instrument in the mid-infrared enables probing of molecular species that are harder to detect in the near-infrared. This has come to the fore with the first MIRI-LRS observation of a candidate hycean world, K2-18 b, with potential signs of dimethyl sulfide in its atmosphere. The statistical significance of this result has been debated in subsequent works, arguing instead for the possibility of random noise, instrumental systematics, or a different molecule. The same applies to similar spectra reported for several other
exoplanets using MIRI-LRS and interpreted with similar
retrieval architectures. In this work, we distinguish between these possibilities with a homogeneous survey of MIRI-LRS transmission spectra of 10 diverse
exoplanets, from temperate sub-Neptunes to hot rocky
planets and gas
giants. We first perform a comparative assessment of the spectra, considering fits with featureless models and pairwise correlations, followed by extensive atmospheric
retrievals. With the
retrievals, we search for over 150 trace species in the atmosphere of each
planet. We find hints of complex molecules in the temperate sub-Neptunes and candidate hycean worlds K2-18 b, TOI-732 c and TOI-270 d, similar to previous works, but not in the other seven
planets. Our results indicate that the observed spectral features are likely due to molecular absorption rather than instrument systematics or noise, and underscore these temperate sub-Neptunes as a unique class of
planets. More observations are required to robustly identify the specific molecules and constrain the underlying chemical processes, biotic or abiotic.
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All authors Martin Binet, Nikku Madhusudhan, Måns Holmberg, Subhajit Sarkar
Quantum Physics
Memory-Optimal Sequential Synthesis of Multimode Gaussian Transformations
Fucheng Guo, Frank Mueller and Yuan Liu
In modular
quantum computing architectures, communication between hardware modules is mediated by traveling qumodes sent through transmission lines. Each output qumode interacts with the emitting module only once through a beam-splitter-type interaction and becomes inaccessible to that module after emission. Information required for subsequent outputs must therefore remain in long-lived
memory qumodes. For a prescribed multimode Gaussian transformation on $N$ qumodes, this work determines the minimum
memory cost for any given emission order, constructs an explicit sequential protocol attaining this minimum, and develops a greedy method for identifying
memory-efficient emission orders. The transformation is represented by a
symplectic matrix $S$, specified either directly or through a Gaussian gate sequence. The exact minimum
memory cost is obtained from the ranks of submatrices of $S$ and further reduces to a support-based counting rule whose computational cost is linear in the size of the support data. When $S$ is specified directly, a
matrix-based protocol attains the minimum
memory cost. If instead $S$ is specified through a gate sequence, the original gates can be reused without additional synthesis, although the resulting
memory usage need not be minimal. Gaussian transformations with local support on a $D$-dimensional cubic
lattice can be realized sequentially with $O(N^{(D-1)/D})$
memory qumodes. The protocols also apply to non-Gaussian inputs, including GKP and cat states, and thereby provide an explicit, resource-efficient scheme for intermodule communication in modular architectures for universal continuous-variable
quantum computation.
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Quantum Physics
Quantum-State Texture Dynamics: Theory and Experiment
Carlos H. S. Vieira, Xinfang Nie, Dawei Lu et al. (+1 more)
Quantum-state texture (QST) has found applications in several fields from
quantum foundations and computation to
quantum criticality. However, a general theory of QST dynamics under arbitrary physical processes remains unavailable, limiting both its practical application and experimental exploration. Here, we demonstrate that the QST response to an arbitrary finite-dimensional channel is fully encoded in the dual
evolution of a single reference state. This description yields necessary and sufficient conditions for texture preservation and implies exact conservation under all free-unital dynamics. Using a
nuclear magnetic resonance
quantum processor, we experimentally verify these predictions across distinct channel classes. Furthermore, we show that local QST measurements provide an operational signature of entangling gates in
circuit layers. Our results establish
quantum-state texture as a resource and a practical diagnostic tool in
quantum information processing.
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All authors Carlos H. S. Vieira, Xinfang Nie, Dawei Lu, Fernando Parisio
Statistical Mechanics
Diffusion under competing bulk and surface stopping mechanisms
Yilin Ye
We investigate reflected
diffusion in a bounded domain subject to two independent, competing stopping mechanisms: an exponentially distributed bulk lifetime of rate $p$ and a surface reaction triggered when the boundary local time exceeds an independent exponential threshold of rate $q$. Denoting by $T$ the stopping time and by $L$ the acquired boundary local time at stopping, we derive their marginal distributions, joint Laplace transform, and complete hierarchy of mixed moments. These statistics are determined by the splitting probability $\phi$ that surface reaction occurs before bulk decay. In particular, we establish the identity $p\expect{T}+q\expect{L}=1$ and show that the cumulative risk $pT+qL$ is exponentially distributed with unit rate. We further obtain equivalent representations of $\phi$ in terms of the Robin-
Laplacian and the generalized Steklov spectra. Explicit results for a three-dimensional ball reveal how competing rates $p,q$ control $\phi$ and the $(T,L)$ statistics. Monte Carlo simulations test the universal cumulative-risk law.
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Fluid Dynamics
An Aeroelastic Solver Integrating Reformulated-Vortex-Particle and Finite-Element Methods across Non-Conforming Interfaces
Neeraj Balachandar, A. Padmaprabhan and Vishnu R. Unni
We present $\texttt{VarFlExI}$ (Variable Fidelity Unsteady Flow-FEniCS Exchange Interface), a modular aeroelastic solver for modeling two-way fluid-structure interaction (FSI) of flexible lifting surfaces. The framework employs a reformulated
Vortex Particle Method (rVPM) to solve the incompressible Navier-Stokes equations without the need for computationally expensive volumetric meshing, while supporting variable-fidelity aerodynamic modeling using the $\texttt{FLOWUnsteady}$ framework. On the structural side, a Reissner-Mindlin plate formulation is discretized using the finite element method and integrated in time through the generalized-$\alpha$ method, with the nonlinear
equilibrium equations solved using a Gauss-Newton procedure within the $\texttt{FEniCS}$ framework. Fluid and structural solvers are coupled through an explicit staggered partitioned scheme, ensuring conservation of virtual work for load and displacement transfer across the non-matching interface. To accommodate the multi-representative nature of the aerodynamic loads and geometry, the interface coupling employs separate work-conservative force and reverse-geometry transfer operators via a common intermediate interface. The framework is validated against water-tunnel experiments, demonstrating accurate prediction of the coupled aeroelastic response rather than independent validation of the constituent solvers. The computational efficiency of the meshless aerodynamic solver enables simulations at significantly lower computational cost while maintaining accuracy. The solver is further evaluated through sensitivity analyses and parameter studies spanning different flow conditions, structural properties, and coupling parameters.
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Instrumentation and Methods for Astrophysics
What is new in NuRadioMC: Multilayer Analytic Raytracer
Hannes Warnhofer, Sjoerd Bouma, Vital De Henau et al. (+14 more)
NuRadioMC is a framework for the simulation of ultra-high-energy
neutrino detectors that measure the
radio signal emitted in
neutrino-induced particle cascades used in different
radio neutrino experiments. We present an extension to the analytic raytracing method for multilayered exponential refractive index models, where the full refractive index profile is described by a set of different single-exponential layers, supporting realistic medium descriptions at various experiment sites while maintaining computational efficiency. This approach also enables a realistic exponential refractive index description of the atmosphere and allows us to model signal propagation over non-smooth changes in the refractive index. This report outlines the fundamentals of the multilayered analytic raytracing method and shows some applied examples.
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All authors Hannes Warnhofer, Sjoerd Bouma, Vital De Henau, Bryan Hendricks, Jakob Henrichs, Nils Heyer, Enrique Huesca Santiago, Annanay Jaitly, Philipp Laub, Anna Nelles, Martin Ravn, Felix Schlüter, Zeynep Su Selcuk, Karen Terveer, Christian Glaser, Christoph Welling, Philipp Windischhofer
Quantum Physics
Merle Stahl, Robert J. Banks, Matthias Traube et al. (+4 more)
Protein-
protein interaction (PPI) network
alignment combines topological and sequence information to identify conserved modules across species, but global
alignment remains challenging: heuristics sacrifice optimality, while exact methods lack scalability. We model the
alignment as a weighted maximum common induced subgraph problem and reformulate it through the modular product graph to a minimum-weight vertex cover on the complement, with node weights carrying sequence similarity. To solve this problem, we develop a hybrid framework combining kernelisation, branch-and-bound, and seven
Quantum Approximate Optimisation
Algorithm (QAOA) formulations. These formulations differ in how the cover constraints are enforced, from penalty terms in the cost
Hamiltonian to mixers confined to the feasible subspace. For single round QAOA, we derive closed-form expressions for the expected cost of four circulant mixer variants, enabling performance characterisation without
circuit simulation. Applied to synthetic and real-world networks reduced to KEGG pathways, the QAOA formulations achieve high topological conservation on the aligned core while at least maintaining biological conservation comparable to leading classical aligners, at the cost of reduced node coverage. Across selected KEGG pathways, the aligned subnetworks retain disease-associated
proteins, preserving biologically relevant information. Cheaper formulations leave more edges uncovered, while enforcing feasibility in the mixer raises
circuit depth by one to two orders of magnitude. Together, these results highlight the potential of
quantum optimisation for PPI network
alignment and the resource trade-offs that will shape its scalability as
quantum hardware matures.
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All authors Merle Stahl, Robert J. Banks, Matthias Traube, Josua Unger, Wolfgang Lechner, Jan Baumbach, Mhaned Oubounyt
Mathematical Physics
Representation Theory of Canonical Commutation Relations Arising from the Quantization of the Klein-Gordon Equation with an External Potential
Yasumichi Matsuzawa, Itaru Sasaki and Akito Suzuki
We investigate the Weyl representation of the canonical commutation relations for a model describing a quantized massive scalar field under the influence of an external potential. The main problem is to determine whether the Weyl representation remains equivalent to or becomes inequivalent to the original one when the mass and/or potential are changed. This problem is reduced to the study of Schrödinger operators. It turns out that the Weyl representations are inequivalent when the masses differ. Moreover, when the masses are the same, the transition between equivalence and inequivalence occurs at the decay rate $-3/2$ of the difference between the potentials. This contrasts with the decay rate $-1$ that defines the short-range condition in scattering theory.
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Chemical Physics · Cross-listed from cs.LG
Hessian-Informed Conformation Augmentation for Potential Energy Surface Curvature in Machine Learning Interatomic Potentials
Bumju Kwak and Jeonghee Jo
While machine-learning interatomic potentials (MLIPs) have successfully learned potential energy surfaces (PES) and atomic forces, many practical applications, such as vibrational analysis and transition state search, rely heavily on the PES Hessian. Yet standard MLIPs are trained on energy and forces only, and using the Hessian as an additional training objective requires backpropagation whose
memory cost grows quadratically with the number of atoms. To address these limitations, we propose two Hessian-derived data augmentation schemes: isotropic Gaussian displacement (UniAug) and normal mode-weighted displacement (ModeAug). Both methods utilize simple Taylor expansions, generating physically grounded molecular structures with highly accurate energy and force labels. By preserving the underlying MLIP architecture and training procedure, this approach contributes to improving energy and force predictions in various
benchmarks. Comprehensive evaluations across non-
equilibrium and
equilibrium datasets demonstrate that our approach enhances model accuracy where reference forces are large and training data are limited.
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High Energy Physics (Phenomenology)
New measurements in leptonic kaon and pion decays: experimental and theoretical perspectives
Lukas Allwicher, Stefan Alexandru Ghinescu, Federico Mescia et al. (+2 more)
We study the future prospects for precision measurements of purely leptonic charged-current kaon and pion decays. Together with the ratio of leptonic widths $R_K^\nu=\Gamma(K\to e\nu)/\Gamma(K\to\mu\nu)$, we consider the single ratios $R_{K\pi}^{\ell=\mu,e} = \Gamma(K \to \ell\nu) / \Gamma(\pi \to \ell\nu)$, for which many experimental uncertainties cancel, as well as the double ratio $R_{K\pi}^e / R_{K\pi}^\mu$, which provides a particularly sensitive probe of new physics. This study is timely in light of two converging developments. On the experimental side, a new conceptual design for a dedicated setup based on a slow-extracted
proton beam and a multi-year data-taking program, is expected to achieve a precision at the few $10^{-4}$ level. On the theory side, recent
lattice-QCD calculations have reached a comparable level of accuracy. Finally, we assess the impact of these next-generation measurements on searches for physics beyond the Standard Model and show that they can provide constraints that are either competitive with or complementary to existing bounds.
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All authors Lukas Allwicher, Stefan Alexandru Ghinescu, Federico Mescia, Tommaso Spadaro, Lucine Tabatt
Earth and Planetary Astrophysics
Planetary gas gaps and kinematic signatures in the planet forming disk around WISPIT 2
Nienke van der Marel, Jochen Stadler, Andres F. Izquierdo et al. (+7 more)
The
giant planet formation process in disks of gas and
dust surrounding young
stars is observationally still poorly constrained. Direct detection of protoplanets within the disk remains limited with current facilities. Indirect observational evidence of protoplanets through substructures or deviations from Keplerian rotation in the gas remains ambiguous in absence of detected
planets. The lack of the combined detection of substructures and their corresponding
planets makes it challenging to connect the
planet formation process to the host environment. Observations with the Atacama Large Millimeter Array (ALMA) reveal clear detections of gas gaps and kinematic signatures in the WISPIT 2 protoplanetary disk that are cospatial with the locations of previously detected
giant protoplanets. The newly identified gas gaps, observed in both the 12CO integrated intensity map and its rotation curve, correspond with the previously identified gaps in scattered light. Their morphologies are shown to be consistent with eccentric gaps, as expected from
planet-disk interaction models of massive
planets. The lack of eccentricity in the outer disk can be explained if a third
planet is present in the system. The observations of WISPIT 2 provide a long-sought empirical bridge between kinematic signatures, gas gaps and
giant planet formation in disks.
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All authors Nienke van der Marel, Jochen Stadler, Andres F. Izquierdo, Ruobing Dong, Bertram Bitsch, Jake Byrne, Richelle van Capelleveen, Chloe Lawlor, Christian Ginski, Matthew Kenworthy.
Quantum Physics
TETRIS-Q: Tiling-based Effective Transient-fault Reduction on Interleaved Superconducting Qubits
Marzio Vallero, Gioele Casagranda, Flavio Vella et al. (+1 more)
The struggle of the hour in
quantum computing research is achieving effective suppression of the error mechanisms induced by the interaction of external radiation with superconducting
quantum devices. Despite the rapid advancements in
quantum error correction (QEC) of recent years, radiation-induced faults are yet to be fully addressed. These events are known to be the cause of simultaneous correlated defects in
qubits that lie onto a single substrate, ultimately jeopardising QEC code effectiveness. In this paper, we propose to selectively combine substrate-level
phonon barriers and QEC interleaving via a planar-mesh tiling
algorithm, TETRIS-Q, reaching efficient and effective suppression of radiation events. Our cross-layer solution comes at no extra cost in terms of QEC code execution or decoding time. We model and simulate radiation-induced transient faults over a plethora of barrier and QEC interleaving configurations. Through more than 51 million
quantum circuit simulations, we show peak logical error reductions of more than $99.8 \%$, together with an $80\%$ reduction of the observable transient duration with permeable barriers. We find that sparser tiling can reach comparable performance to single
qubit tiling, prompting cost reductions of upwards of $87 \%$ in barrier tracing. By leveraging independent QEC code interleaving, we measure up to one order of magnitude average logical error rate reductions without the use of permeable barriers, and up to three orders of magnitude with the joint usage of barriers.
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All authors Marzio Vallero, Gioele Casagranda, Flavio Vella, Paolo Rech
Quantum Physics
The marginal is pretty good
Lukas Schmitt, Gui-Long Jiang, Shi-Bing Li et al. (+1 more)
One-shot information theory measures often require an optimization over states, but the form of these optimizers can be complicated or depend on the initial problem in nonlinear ways. In this note, we show that in many instances using the marginal instead of the optimal state is sufficiently good and only changes the result by a small factor. We prove that for the Petz–Rényi and sandwiched–Rényi divergences of order $\alpha\in(0,1)$, replacing the optimizing state on $B$ by the marginal $\rho_B$ results in a multiplicative overhead of at most $1/\alpha$.
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All authors Lukas Schmitt, Gui-Long Jiang, Shi-Bing Li, Joseph M. Renes
Quantum Physics
A double-resonator coupler for high-fidelity two-qubit gates between superconducting qubits
Seunghyeon Jin, Seungha Woo, Shinyoung Hwang et al. (+6 more)
Tunable couplers have enabled two-
qubit gate fidelities in superconducting
quantum processors to approach $99.9\%$, yet simultaneously suppressing residual interactions and maintaining flexible
qubit-frequency allocation remain central challenges for scaling. Here, we propose a double-resonator coupler (DRC) consisting of two resonators interconnected by a single Josephson junction and a capacitor. The hybridized resonator modes provide two mediated exchange paths whose interference controls the
qubit-
qubit interaction. The DRC enables complete cancellation of residual $ZZ$ interaction for
qubit-
qubit detunings well outside the straddling regime, even without direct inter-
qubit capacitance, thereby relaxing constraints on frequency allocation and
qubit placement. Away from the idle point, the same
circuit provides a strong $ZZ$ interaction of approximately $70\,\mathrm{MHz}$, enabling a $20\,\mathrm{ns}$ controlled-Z gate with simulated coherent infidelity below $10^{-5}$. These results establish the DRC as a flexible single-junction coupler architecture for high-fidelity superconducting
quantum processors.
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All authors Seunghyeon Jin, Seungha Woo, Shinyoung Hwang, June-Young M. Lee, Jeongmin Shim, Sunje Kim, Dae Seok Han, Jaeho Shin, Eunjong Kim
Mesoscale and Nanoscale Physics
Robustness of RKKY interactions across a Weyl node-annihilation transition
João V. F. Alves, Joelson F. Silva and Luis G. G. V. Dias da Silva
Weyl semimetals (WSMs), with their unique topological properties and distinct electronic structure, exhibit intriguing properties when either time-reversal or inversion
symmetries are broken. In this work, we consider the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between
magnetic impurities in time-reversal
symmetry-breaking WSMs. We derive analytical expressions for the full RKKY exchange tensor in arbitrary two-band spinful
lattice systems. Our approach reveals both Heisenberg, anisotropic Ising and Dzyaloshinsky-Moriya terms, which can be calculated by energy-integrating real-space Green's functions across the entire Brillouin zone, with the band edge acting as a natural energy cutoff. We apply this framework to study a two-band tight-binding model for a time-reversal
symmetry-breaking WSM that interpolates between a Weyl phase with well-separated
chiral nodes and a quadratic band-touching semimetal phase. Remarkably, the spatial profile, magnitude, and anisotropic tensor structure of the exchange couplings remain persistent across the node-annihilation transition. This topological robustness reveals that short- and intermediate-range RKKY interactions are mediated by the global, Brillouin-zone-integrated
quantum metric of the full valence band rather than being strictly dictated by local low-energy Berry
curvature monopoles. These findings demonstrate the necessity of full-band tight-binding formulations when predicting real-space
magnetic interactions, providing key insights for electric-field tuning of
magnetic anisotropy and constructing realistic models of heavy-
fermion and Weyl-Kondo semimetals.
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Optics
Screening bolt loosening in a four-bolt plate with global FRF correlation and local FRAC maps from full-field laser Doppler vibrometry
Berkay Kullukcu, Robin Pianowski, Mehmet Sait Özer et al. (+2 more)
Full-field
laser Doppler vibrometry (LDV) can reveal how bolt torque loss redistributes a frequency response function (FRF) over an entire structure rather than only at a few sensor positions. This work presents a screening procedure for a four-bolt aluminum plate using pointwise amplitude and phase exports of scanned H1 FRFs. Candidate resonances were selected from the all-tight spatial RMS spectrum and tracked in four single-bolt 0 Nm cases. Seven baseline responses remained trackable within prescribed group-specific search windows and were retained as experimental resonance groups RG1-RG7; a dimensionless plate-frequency coefficient was reported alongside each measured frequency. Global changes were quantified using amplitude-only and complex, phase-retaining modal-assurance dissimilarities, and local changes were evaluated using matched-window FRAC-deficit maps and a normalized hotspot-area fraction. The retained groups separate into low-, intermediate-, and high-distortion responses, while the local maps distinguish compact joint-centered changes from distributed FRF redistribution. The workflow therefore links global FRF distortion with spatially resolved interpretation without relying on a trained classifier or specimen-specific node labels.
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All authors Berkay Kullukcu, Robin Pianowski, Mehmet Sait Özer, Ercan Altinsoy, Dina Hannebauer
Soft Condensed Matter
Coarse-graining far-from-equilibrium dynamics using oblique projectors
Gerhard Jung
We generalize the Mori-Zwanzig projection operator formalism by introducing an oblique projector using biorthogonal variables to coarse-grain the dynamics of systems far from
equilibrium, such as active or living matter. Improving on previously used orthogonal projectors, the oblique projector correctly decomposes the emergent interactions of the coarse-grained particles into systematic and
stochastic contributions. We show that the formalism directly connects to established results in non-
equilibrium linear response theory and adiabatic perturbation theory. Based on this formalism, we develop a coarse-graining
algorithm which we apply to extract the emergent non-
equilibrium chiral dynamics of a passive tracer in a
chiral active bath. Our theory correctly predicts the odd transport properties and a confinement-induced shift of the
chiral frequency of the tracer.
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Astrophysics of Galaxies
Stellar Population and Dynamical Modeling of Galaxies with Kinematically Misaligned Components: Age and Metallicity of Structural Components
V. S. Goradzhanov, K. O. Parfenov, D. D. Mishurin et al. (+1 more)
We present
stellar population and orbit modeling of two
galaxies with kinematically misaligned components, PGC 35706 and LEDA 2220522, extending previous Schwarzschild dynamical models. Using spatially resolved age and
metallicity maps from NBursts full spectral fitting of MaNGA data with the E-MILES grid, we solve a regularized bounded linear inverse problem that assigns light-weighted SSP-equivalent age,
metallicity, and mass-to-light ratio to orbital
cells in the $(R,\lambda_z)$ plane. Component means and radial profiles use projected mass within the actual MaNGA field of view; profile segments with local component fractions below $1\%$ are treated as weakly constrained. In LEDA 2220522, the counter-rotating disk is younger than the co-rotating disk, $1.32\pm0.04$ versus $1.61\pm0.06$ Gyr, and more metal-rich, $[\mathrm{M/H}]=-0.450\pm0.043$ versus $-0.613\pm0.024$. Its rotation agrees with that of the H$\alpha$ ionized gas, supporting late supply of chemically enriched retrograde gas without requiring multiple
accretion episodes with alternating angular momentum. In PGC 35706, the counter-rotating disk contains $8.8\%$ of the mass in the observed field and is formally older than the co-rotating disk by $1.36\pm0.51$ Gyr and more metal-poor by $0.130\pm0.046$ dex. These differences are preliminary because the projected data provide limited support. Fifty Monte Carlo realizations confirm stability of the projected maps against statistical noise, but not uniqueness in individual phase-space
cells. The
stellar population and orbit approach is therefore applicable to MaNGA data when local projected component fractions and systematics from regularization and the dynamical model are explicitly considered.
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All authors V. S. Goradzhanov, K. O. Parfenov, D. D. Mishurin, O. K. Sil'chenko
High Energy Physics (Theory)
CFT characters from localization
Lorenz Eberhardt, Duarte Fragoso and Hessel Posthuma
We explain a general procedure to compute characters of
chiral algebras of 2d (S)CFTs geometrically from their coadjoint orbits, in analogy with the coadjoint orbit method for finite-dimensional Lie groups. We demonstrate that this method can be used to give concise rederivations of the characters of the Virasoro
algebra, Kac-Moody
algebras, as well as supersymmetric generalizations.
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High Energy Astrophysical Phenomena
Exploring the connection between Fast Radio Bursts and binary neutron star mergers
Barbara Patricelli, Maria Grazia Bernardini, Cecilia Sgalletta et al. (+1 more)
Fast
Radio Bursts (FRBs) are highly energetic
radio sources whose duration is of the order of milliseconds. The physical origin of these sources is still unknown. Many models suggest magnetars as possible progenitors of FRBs, and this is supported by the association between FRBs and the
Galactic magnetar SGR 1935+2154; other proposed progenitors include binary
neutron star (BNS) mergers, that are themselves linked to magnetar formation. In this work we investigate the possible connection between FRBs and BNS mergers, including magnetars that might be produced in such events, by comparing the detection rates inferred from synthetic BNS and associated FRB populations with the rates observed by CHIME. We produce a synthetic catalog of BNS mergers by combining recent theoretically predicted BNS merger rate as a function of
redshift and the
neutron star mass distribution inferred from measurements of
Galactic BNSs. Using this catalog we predict the number of BNS systems ending as magnetars (stable or supramassive
neutron star) or black holes (formed promptly or after the collapse of a hypermassive
neutron star) for different equations of state. We then simulate for each BNS (and therefore for each magnetar remnant) an associated FRB and estimate how many of them can be potentially detected by CHIME. We find that the rate of BNS mergers and the rate of magnetars produced after BNS represents a non-negligible fraction of the FRBs detected by CHIME, both repeating and non-repeating. Although additional formation channels need to be considered to account for the entire population of FRBs, the existence of a fraction of FRBs that might genuinely be associated to BNS mergers has profound implications in the context of multi- messenger astronomy, supporting the systematic searches of coincident detections of FRBs and GWs from a BNS merger with current and future facilities.
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All authors Barbara Patricelli, Maria Grazia Bernardini, Cecilia Sgalletta, Michela Mapelli
Instrumentation and Methods for Astrophysics
Active focal plane phase mask coronagraphy with a discrete pixelated device: I. Study of the theoretical performance trade space
Liurong Lin, Axel Potier, Ruben Tandon et al. (+2 more)
Recent advances in high-contrast
exoplanet imaging instrumentation have introduced the concept of adaptive coronagraphy. For example,
liquid-
crystal-on-silicon spatial light modulators can be used as programmable phase masks or digital micro-mirror devices as configurable pupil apodizers. Adaptive coronagraphy offers the ability to adjust in real time to changing observing conditions and science goals, such as switching between blind surveys and follow-ups of known objects, or optimizing observations of multiple
star systems including binaries and triples. At the same time, these active devices present challenges: finite spatial sampling, limited phase resolution, and the scalar nature of their modulation can all reduce coronagraphic performance. We look at the performance of a coronagraph utilizing pixelated discrete focal plane masks in function of various key parameters, notably spatial sampling, phase resolution, temporal jitter, and calibration errors. The analysis includes several FPM designs:
vortex, four-quadrant phase mask, Roddier and Roddier, dual-zone phase mask, and azimuthal cosine phase mask. Both monochromatic and 20% broadband imaging conditions are considered, along with the absence or presence of a central obstruction from a secondary mirror in the
telescope pupil, associated with variations in Lyot stop sizing. Our results identify the main error sources and limiting parameters of scalar, pixelated FPM coronagraphs. Under ideal conditions, performance is mainly limited by spatial sampling and chromaticity of scalar phase modulation. These devices are therefore primarily relevant to ground-based high-contrast imaging rather than the deeper contrast regimes required by future space observatories. Although motivated mainly by SLM implementations, the conclusions should also apply to other discrete pixelated focal-plane phase masks.
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All authors Liurong Lin, Axel Potier, Ruben Tandon, Lucas Marquis, Jonas G. Kühn
Data Analysis and Statistics · Cross-listed from stat.ML
FluxDisco: Symbolic Regression for Stoichiometric Dynamical Systems via Monte Carlo Graph Search
Cassandra Durr, Alvaro Köhn-Luque, Chris Jewell et al. (+1 more)
Dynamical symbolic regression methods identify governing differential equations from noisy data, balancing interpretability and predictive accuracy. However, standard methods often produce expressions that violate known physical laws. To address this, we propose FluxDisco, a physics-informed framework tailored for flux-based, stoichiometric ODE systems. By leveraging a known stoichiometry, we reduce the expression search space and ensure physical adherence. Our framework adapts the Monte Carlo Graph Search
algorithm for the unique challenges associated with joint flux discovery of stoichiometric systems. We evaluate our method across a range of physical and biological systems, demonstrating its ability to accurately recover governing dynamics through interpretable equations.
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All authors Cassandra Durr, Alvaro Köhn-Luque, Chris Jewell, Lloyd A. C. Chapman
Instrumentation and Methods for Astrophysics
Laboratory characterization of Hierarchical Fringe Tracking
Roxanne Ligi, Stéphane Lagarde, Romain Petrov et al. (+7 more)
One of the main limitations in long-baseline interferometry lies in its fringe tracking sensitivity. The challenge is therefore to maximize this sensitivity while minimizing the spreading of the signal on the detector. This is the goal at the core of the hierarchical fringe tracking (HFT) concept. We present the laboratory characterization of the $2^{nd}$ generation HFT chips operating in the near infrared (H band) for up to 4
telescopes with more linear phase and group delay
estimators, allowing a strong simplification of the tracking
algorithm. We show a comparison between theoretical intensity outputs for an optimized phase delay chip, and the laboratory measurements of two chips with different designs. The results do not reach the expectations but get close to them with the 10-outputs chip. Ultimately, this new chip is intended for implementation on the VLTI, CHARA or on the future Xuyi 100m-baseline
Stellar Interferometer using three
telescopes.
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All authors Roxanne Ligi, Stéphane Lagarde, Romain Petrov, Sylvie Robbe-Dubois, Julien Dejonghe, Fatmé Allouche, Teng Xu, Wei Wei, Massinissa Hadjara, Abdelkarim Boskri
High Energy Physics (Phenomenology)
Exothermic Dark Matter at LZ
Carlos Henrique de Lima
We investigate whether the high-energy
nuclear recoil reported by the LUX-ZEPLIN (LZ) experiment can be explained by exothermic dark matter. We realize this framework in a minimal inelastic dark
photon model and show that both freeze-out and low-reheating-temperature freeze-in cosmologies can reproduce the observed rate, with GeV-scale mediator masses and small kinetic mixing. We find that the LZ event can occur in a preferred parameter region with dark matter mass around $m_\chi \sim 30-200~\mathrm{GeV}$, and mass splitting $\delta \sim 0.5-1~\mathrm{MeV}$. The scenario is largely insensitive to
halo uncertainties and has robust predictions for different targets. In particular, argon and germanium detectors are expected to observe events at energies above the current xenon window.
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Quantum Physics
Optimal inequalities for completely bounded polynomials and the limitations of quantum query algorithms
Francisco Escudero Gutiérrez, Miquel Saucedo and Carlos Palazuelos
We consider the problem of establishing limitations on the power of
quantum query
algorithms via the completely bounded
polynomial method. In particular, we prove several optimal functional inequalities involving different notions of completely bounded
polynomials. These inequalities lead to limiting
theorems for the power of
quantum query
algorithms that improve on prior works. 1. An optimal root-influence bound for block-multilinear
polynomials. Prior work showed that block-multilinear
polynomials $p$ of degree $t$ satisfy a root-influence bound, $\|p\|_{\text{cb}}\geq \sum_i \sqrt{\mathrm{Inf}_i[p]}/t^2$, which is stronger than the bound appearing in the Aaronson-Ambainis
conjecture. We find the optimal constant in that inequality: $\|p\|_{\text{cb}}\geq \sum_i \sqrt{\mathrm{Inf}_i[p]}/t$. Since the amplitudes of
quantum algorithms that query disjoint blocks of inputs-such as $t$-fold forrelation- are block-multilinear
polynomials with $\|p\|_{\text{cb}}\leq 1,$ our inequality shows that they satisfy $t\geq \sum_i\sqrt{\mathrm{Inf}_i[p]}$. We prove that this inequality yields both a more efficient classical simulation than prior results based on the Aaronson-Ambainis argument, and a qualitative improvement: all classical queries are nonadaptive. 2. Optimal
Fourier growth of the highest level of
quantum query
algorithms. We show that for every
polynomial $p$ defined on $\{-1,1\}^n$ of degree $2t$, the
Fourier Growth at the level $2t,$ namely $\|\widehat p_{2t}\|_{\ell_1}$, satisfies $\|\widehat p_{2t}\|_{\ell_1}\leq (en/(2t-1))^{\frac{2t-1}{2}}\|p\|_{\text{cb}}$. This is optimal up to the factor $e$, as witnessed by $2t$-fold forrelation. As
quantum query
algorithms that make $t$ queries (to the whole input) satisfy $\|p\|_{\text{cb}}\leq 1$, this yields a
Fourier growth bound for these
algorithms, partially resolving a question by Girish (STOC, 2026).
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Accelerator Physics
Indirect Integration of Longitudinal and Transverse Wake Potentials for Unequal Beam Pipes and Arbitrary Beam Velocity
Igor Zagorodnov and Dmitry Bazyl
Indirect integration replaces the long uniform beam-pipe parts of a wakefield calculation by field problems in the pipe cross sections. Earlier ultrarelativistic methods were developed mainly for the longitudinal wake, whereas the transverse wake was usually obtained from the Panofsky–Wenzel
theorem. We derive indirect formulas that complete a transverse Lorentz-force integral already accumulated in a time-domain calculation. At $\beta=1$, each semi-infinite tail is found from a Dirichlet Poisson problem driven by $E_z$ and a Neumann Poisson problem driven by $cB_z$, describing the TM and TE contributions, respectively. We obtain both a fixed-time moving-window representation and a fixed-plane time-history representation for equal or unequal input and output pipes. The method is then extended to a rigid bunch moving with constant velocity $0<\beta c<c$. The longitudinal correction satisfies an anisotropic
elliptic equation in $(x,y,s)$ and provides an additional source for the transverse TM problem. In a two-port finite-reference convention, the complete fields, including space charge, are integrated directly between two fixed planes, while the semi-infinite tails are calculated after subtraction of the stationary field in each pipe. The resulting Panofsky–Wenzel relation contains the difference of the stationary transverse electric fields at the two ports. Numerical tests for an unequal rectangular step-out at $\beta=1$ and $\beta=0.8$ confirm the transverse indirect integration and the unequal-pipe boundary term.
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Superconductivity
Dynamical Reduction of Two Series Josephson Junctions to a Synthetic High-Transparency Josephson Element
Claudio Guarcello, Sergio Pagano, Carlo Barone et al. (+3 more)
Two conventional Josephson junctions connected in series can reproduce, in the static limit in which the currents through the capacitive and resistive channels are negligible, the current-phase relation of a single effective weak link with tunable transparency. Therefore, the two-junction series can be treated as a single synthetic high-transparency element. Here, we investigate to what extent this mapping remains valid under finite-frequency drive and retaining the junctions' resistive and capacitive terms. The full resistively and capacitively shunted junction equations are compared with an effective synthetic element with tunable transparency that retains the synthetic tunable-transparency current-phase relation together with effective capacitive and dissipative terms, thus reducing the two second order degree of freedom system to a single second order degree of freedom. The resulting single-element dynamics is compared with the complete two-junction system under ac excitation. The agreement is quantified through a normalized root-mean-square error between the full and effective voltage waveforms. A broad low-error region is found at low drive frequency, while pronounced deviations emerge as the drive frequency approaches the relevant
plasma-frequency scale and at larger drive amplitudes. The results provide a quantitative dynamical criterion for using the reduced single-element description of a synthetic high-transparency Josephson element in superconducting
circuits.
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All authors Claudio Guarcello, Sergio Pagano, Carlo Barone, Alessandro Bruno, A. Mert Bozkurt, Giovanni Filatrella
Mesoscale and Nanoscale Physics
Electrostatic splitting of an Edge Magnetoplasmon Resonator
Sloän Kouamé, Elric Frigerio, Giacomo Rebora et al. (+10 more)
Edge-magnetoplasmon resonators have been proposed as a powerful tool to detect anyons by introducing a
quantum point contact into an isolated
quantum Hall system probed via radiofrequency radiation. In this paper, we study the effect of a
quantum point contact embedded within an edge-magnetoplasmon resonator and how its polarization influences the propagating magnetoplasmonic mode. Combining dc and rf measurements, we unambiguously evidence the signature of both integer ($\nu = 1$ and $2$) and fractional
quantum Hall states ($\nu = 4/3$ and $2/3$) within the radiofrequency transmission signal. Using electrostatic gating, we determine the physical parameters characterizing the electrostatic edge of an AlGaAs/GaAs based two-dimensional electron gas. We extract the dependence of the cavity perimeter with the gate voltage of the
quantum point contact and fully characterize the path followed by edge magnetoplasmons in this system. Finally, we provide a
geometric model in good agreement with experimental results.
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All authors Sloän Kouamé, Elric Frigerio, Giacomo Rebora, Suvankar Purkait, Yong Jin, Ulf Gennser, Antonella Cavanna, Jean-Marc Berroir, Emmanuel Baudin, Pascal Degiovanni, François D. Parmentier, Gwendal Fève, Gerbold C. Ménard
Superconductivity
Ni-O hybridization as a stabilizer for $s^{\pm}$ superconductivity in La$_3$Ni$_2$O$_7$: a DFT+RPA study
Lauro B. Braz, Daniel D. Rivera, Emmanuel V. C. Lopes et al. (+3 more)
The superconducting gap
symmetry of high-pressure
bilayer nickelates remains under debate, with weak- and strong-coupling approaches yielding different pairing tendencies. In this work, we investigate how the weak-coupling treatment of electronic states away from the
Fermi level influences
magnetic fluctuations and superconductivity in La$_3$Ni$_2$O$_7$. We employ a full-spectrum model based on orthonormalized projections of Kohn-Sham states onto local Ni-$e_g$ orbitals, which preserves the density-functional band structure while redistributing spectral weight over a wide energy range. Compared to a low-energy description, this approach yields enhanced interlayer
spin fluctuations and a commensurate
magnetic instability. Within a
spin-fluctuation framework, these features favor a sign-changing $s^\pm$ superconducting state, whereas low-energy models tend to stabilize $d$-wave pairing. Our results suggest that interlayer coupling in full-energy models may play an important role in shaping the predicted pairing
symmetry of
bilayer nickelates.
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All authors Lauro B. Braz, Daniel D. Rivera, Emmanuel V. C. Lopes, George B. Martins, Gustavo M. Dalpian, Luis G. G. V. Dias da Silva
Statistical Mechanics
Markov chains at the onset of non-reversibility
Gustave Robichon, Cecile Monthus and Werner Krauth
For a one-dimensional path graph and a lifted path graph constructed from a duplication of each of its sites, we study how a reversible Markov chain can be perturbed and gradually driven into non-reversibility. The reversible Markov chain has a transition
matrix that is diagonalizable and features real-valued
eigenvalues and eigenvectors. The left and right eigenvectors form a biorthogonal system. We discuss in concrete examples how the transition
matrix of a non-reversible Markov chain may be diagonalizable or non-diagonalizable, and it may have real
eigenvalues and complex-conjugate pairs. For a number of steady states (flat, square-wave, wedge, V-shape), we compute
eigenvalue spectra on both graphs and discuss the speedup that can be achieved through lifting. We develop a Green's
matrix formalism, which we use to compute Kemeny times and mean first-passage times, and which provides valuable information and allows us to interpret the results for the characteristic times.
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