Instrumentation and Detectors
Test of a partly instrumented highly compact and granular electromagnetic calorimeter in an electron beam of 1 to 6 GeV
Adrián Irles
Highly compact and finely segmented silicon-tungsten electromagnetic calorimeters are being developed within the FCAL collaboration for applications in the LUXE experiment at DESY and future electron-positron
collider facilities. These detectors combine tungsten absorber plates with thin silicon pad sensors, providing a small effective Molière radius and high spatial granularity, which are essential for resolving nearby electromagnetic showers in high-occupancy environments. The fundamental active unit of this calorimeter concept is the Compact Silicon Sandwich (CSIS), integrating a silicon pad sensor together with signal routing, high-voltage distribution and mechanical support in a highly compact structure. The assembly of these CSIS modules is performed within a dedicated infrastructure for silicon detector integration. A partially instrumented prototype of such a calorimeter has been tested in an electron beam with energies between 1 and 6~GeV. First results from the 2025 test beam campaign are presented, including minimum-ionizing particle calibration and preliminary event displays illustrating the shower development in the highly granular detector. These results constitute an important step towards the validation of this technology for LUXE and future
collider experiments.
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High Energy Physics (Phenomenology)
Exclusive Dyon Production in High-Energy Collisions
Luis F. C. Inácio and Werner K. Sauter
In this work, we investigate the exclusive central production of dyons, a particle carrying electric and
magnetic charges, in hadronic interactions at LHC energies, assuming the
photon fusion mechanism. Motivated by predictions from theoretical physics beyond the Standard Model, we analyze the photoproduction of these particles in the ultraperipheral collision regime, employing the equivalent
photon approximation. We estimate the cross-sections for dyons production in
spin 0, 1/2, and 1 scenarios, adopting values for electric and
magnetic charges from the literature. Our results demonstrate a direct correlation between
spin and cross section, predicting a substantially higher probability for the photoproduction of higher-
spin dyons.
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High Energy Physics (Theory)
Quadratic Gauge Transformation
Sunita Singh and Akshit Sharma
Symmetries plays a significant role in understanding the conservation laws in
Quantum field theories. Here, we attempted a quadratic type dimensionless gauge transformation to achieve the invariance in QFTs. We have shown the extensive study of invariance of complex scalar, Abelian and Non- Abelian theories and established the conservation laws. We included an explicit graphical analysis to invoke the invariance. This is studied in a physical context, where different field configurations correspond to the same physical state. The necessity of the covariant derivative is studied in detail, highlighting how it ensures consistent transformation under local
symmetry operations. The meaning of covariance is clarified as the preservation of the form of physical laws under transformations.
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Strongly Correlated Electrons
Trimers in the Extended Hubbard Model
R. R. Montenegro-Filho, D. R. B. Silva, D. Cogollo et al. (+1 more)
The Lieb
theorem is a cornerstone of
quantum magnetism theory in condensed matter. In this work, we investigate the instability of the Lieb insulating ferrimagnetic phase in the extended Hubbard model on a trimer chain at half-filling, with one electron per site, under increasing the nearest-neighbor Coulomb coupling $V$. Our results show that despite a noticeable increase in doublon density with $V$, the ferrimagnetic insulating phase remains robust up to the phase separation (PS) line, which is observed at $V \gtrsim U/4$, where $U$ is the local Coulomb repulsion. Above the PS line, one of the coexisting phases is primarily populated by doublons on one of the two sublattices of the chain. This phase coexists with a metallic, unsaturated
ferromagnetic phase for $U \gtrsim t$, and with a singlet phase for $U \lesssim t$, where $t$ is the intra-trimer hopping amplitude. We estimate the PS and the crossover lines with the help of density
matrix renormalization group calculations.
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All authors R. R. Montenegro-Filho, D. R. B. Silva, D. Cogollo, M. D. Coutinho-Filho
Nuclear Theory
Interplay of quadrupole and octupole degrees of freedom in the Gd isotopes
R. Budaca and S. Pascu
A systematic theoretical investigation of the quadrupole and octupole collective properties across the Gd isotopic chain is performed employing a quadrupole-octupole axially symmetric model. These
nuclei have recently attracted significant
attention following the revelation that the maximum octupole collectivity in this region is located at $^{150}$Gd. The model parameters are optimized by fitting to the low-lying positive and negative-parity energy levels, as well as to known $E0$, $E1$, $E2$, and $E3$ transition strengths. Our primary objective is a simultaneous and unified description of quadrupole and octupole collectivity across the even-even Gd
nuclei in the $84\leqslant N \leqslant96$ range, a region that includes the transition from spherical to rotational
nuclear shapes. The results show a smooth
evolution of the quadrupole deformation, highlighted by a distinct jump at the well-known $N=90$ critical point. The enhancement of quadrupole deformation is also correlated with the loss of non-zero octupole deformation, which is reported only for the lightest $^{148,150}$Gd
nuclei. This translates into a fair agreement with the measured $E3$ strength, predicting a maximum $B(E3)$ value for the $^{152}$Gd isotope.
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Mesoscale and Nanoscale Physics · Cross-listed from cs.LG
Beyond Drug Discovery: The Nanotechnology Molecular Optimization (NMO) Benchmark
Matthias Blaschke, Daniel Kienzle, Zsuzsanna Koczor-Benda et al. (+3 more)
Generative molecular design is shaped by simple proxy
benchmarks for drug-like properties and models pretrained on large pharmaceutical
datasets. This combination yields strong
benchmark metrics but limits transferability to domains structurally distinct from drug discovery. To overcome this limitation and drive discovery toward real, scientifically grounded targets, we introduce the Nanotechnology Molecular Optimization (NMO)
Benchmark, which bridges machine learning (ML) and
quantum materials science. NMO acts simultaneously as a rigorous testbed for the ML community and a discovery engine for nanotechnology research. The suite replaces proxy oracles with
quantum simulations and introduces strict protocols that prioritize scientific utility over leaderboard-oriented overfitting. The physics-based NMO tasks impose hard structural constraints and rugged fitness landscapes, posing fundamentally new requirements on generative models. Notably, advanced molecular optimization methods underperform much simpler approaches on the NMO tasks. We develop a new baseline method identifying the critical components to solve the NMO tasks, including a novel representation for modeling structural constraints and a domain-agnostic pretraining strategy to eliminate pharmaceutical
dataset bias. Our results surpass state-of-the-art physical properties and reveal previously unknown structural motifs, offering new insights for the nanotechnology community and demonstrating that ML can drive genuine scientific discovery.
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All authors Matthias Blaschke, Daniel Kienzle, Zsuzsanna Koczor-Benda, Julian Lorenz, Rainer Lienhart, Fabian Pauly
Instrumentation and Methods for Astrophysics
Radiation effects and noise evolution in NewAthena WFI flight-production sensors
Valentin Emberger, Johannes Müller-Seidlitz, Luisa Ostler et al. (+7 more)
The Wide Field Imager (WFI), one of the two instruments on ESA's next large X-ray observatory NewAthena, is designed for imaging spectroscopy in the 0.2-15 keV range, combining a large field of view with high count-rate capability. Its focal plane is equipped with back-illuminated DEPFET (Depleted p-channel field-effect transistor) sensors that offer high radiation tolerance and provide near Fano-limited energy resolution. Achieving this performance requires an exceptionally low readout noise, with about 3 electrons ENC expected at beginning of life. Consequently, the devices are highly sensitive to radiation-induced changes in noise behavior. In this work, we investigate the impact of both total non-ionizing dose (TNID) and total ionizing dose (TID) on the relevant noise components, including their temperature dependence. A detector module containing a 64x64-pixel sensor from a flight-production wafer was irradiated with 62.4 MeV
protons at the MedAustron accelerator facility in Wiener Neustadt to a total dose equivalent to 2.6 $\cdot$ 10$^9$ 10-MeV-
protons/cm$^2$. The detector was fully biased and operated throughout the irradiation and subsequent measurements, maintaining the nominal operating temperature of 213 K. To study short-term annealing behavior at low temperature, a second, identical module was exposed to a comparable
proton dose within a much shorter timescale by exploiting the available high beam flux. TID effects were investigated separately by irradiating another device with 17.4 keV Mo-K_alpha X-rays to a total dose of 15 Gy. We report the resulting changes in readout noise, dark current, and threshold voltage, and compare them with results from an earlier irradiation campaign using pre-flight sensors. Implications for the instrument's required operating temperature and its expected end-of-life performance are discussed.
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All authors Valentin Emberger, Johannes Müller-Seidlitz, Luisa Ostler, Wolfgang Treberer-Treberspurg, Robert Andritschke, Annika Behrens, Günter Hauser, Peter Lechner, Astrid Mayr, Leonie Sommer
Instrumentation and Methods for Astrophysics
Spectroscopic performance of the electrical functional models for the eXTP SFA-T detectors
Alexander Altmann, Robert Andritschke, Valeria Antonelli et al. (+11 more)
The Spectroscopy Focusing Array (SFA) is one of the three instruments on the eXTP satellite. It consists of six
telescopes plus focal plane cameras, where five are equipped with a Silicon Drift Detector (SDD) array. These five SFA-T (T stands for timing) instruments are used for observations with high time resolution (better than 10 microseconds), high throughput (dead time less than 5 % when observing a 1 Crab source), and good energy resolution (better than 180 eV at 6 keV). This paper presents the spectroscopic performance of the Electrical Functional Modules (EFM) for SFA-T that are assembled and tested at the Max Planck Institute for Extraterrestrial Physics (MPE). A focus lies on the energy resolution at the planned sensor operating temperature of -45 {\deg}C. Additionally, the use of a baffle that covers the pixel edges is studied.
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All authors Alexander Altmann, Robert Andritschke, Valeria Antonelli, Thomas Bechteler, Vadim Burwitz, David Fink, Carlo Fiorini, Max Goretti, Pia Knopp, Peter Lechner, Norbert Meidinger, Jonas Muegge, Christian Sandow, Rafael Strecker
Lattice Field Theory
Isospin-Driven Splitting of Chemical Potentials in Isobar Collisions from Lattice QCD
Heng-Tong Ding, Jin-Biao Gu, Arpith Kumar et al. (+1 more)
Strong
magnetic fields produced in relativistic heavy-ion collisions can modify fluctuations of conserved charges and, consequently, their associated chemical potentials. We present first-principles $(2+1)$-
flavor lattice-QCD results for isospin-driven splittings of conserved-charge chemical potentials between the isobar systems $^{96}_{44}\mathrm{Ru}+^{96}_{44}\mathrm{Ru}$ and $^{96}_{40}\mathrm{Zr}+^{96}_{40}\mathrm{Zr}$ in the QCD crossover region, both at vanishing and nonzero
magnetic fields along the pseudo-critical line $T_{pc}(eB)$. We outline a framework that, under strangeness neutrality and charge-to-
baryon ratio $r\equiv n_{\rm Q}/n_{\rm B}$, maps the isospin difference between two
nuclei, as encoded in $r_{\rm Zr}$ and $r_{\rm Ru}$, onto splitting ratios $\Delta\mu_{\rm Q}/\Delta\mu_{\rm B}$, $\Delta\mu_{\rm S}/\Delta\mu_{\rm B}$, and $\Delta\mu_{\rm S}/\Delta\mu_{\rm Q}$ as functions of $\mu_{\rm B}(r_{\rm Ru})/\Delta\mu_{\rm B}$. Using continuum-estimated
lattice results for the leading-order coefficients $q_1\equiv(\mu_{\rm Q}/\mu_{\rm B})_{\rm LO}$ and $s_1\equiv(\mu_{\rm S}/\mu_{\rm B})_{\rm LO}$, we find that, at vanishing
magnetic field, the splitting ratios are of similar magnitude to recent
Bayesian extractions from
STAR isobar data and yield $\Delta\mu_{\rm Q}<0$ and $\Delta\mu_{\rm S}>0$, with the electric-charge sector dominating. At nonzero
magnetic fields, the splitting ratios show only moderate $eB$ dependence. We therefore further examine Ru–Zr differences in the normalized
magnetic-field response of chemical-potential ratios, particularly those involving $\mu_{\rm Q}/\mu_{\rm B}$, which display a pronounced enhancement in
lattice QCD. We also present
hadron resonance gas (HRG) results and experimentally motivated proxy observables with kinematic cuts to facilitate contact with experiment.
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All authors Heng-Tong Ding, Jin-Biao Gu, Arpith Kumar, Jia Ni
Medical Physics
Compact deep learning pipeline for particle track reconstruction in the pCT detector system
B. Dudás, G. Papp, G. G. Barnaföldi et al. (+1 more)
Proton computed
tomography (pCT) requires both fast and accurate reconstruction of particle trajectories and kinetic energies to achieve clinically viable image formation. Traditional distance-based matching
algorithms often fail under the combined effects of multiple Coulomb scattering and track crossings and most importantly many of them take too much computation time, motivating the use of lightweight deep learning models that can be evaluated rapidly. In this work, we develop a two-stage reconstruction pipeline consisting of (i) a neural-network-assisted tracking module and (ii) a kinetic-energy estimation model. For the tracking task, compact multilayer perceptrons are trained to predict the expected hit position in the subsequent detector layer, providing a physically informed prior that substantially reduces ambiguities in bipartite matching. Furthermore, ambiguous tracks are flagged and excluded from the final analysis. Our training data is provided by OpenGATE simulation toolkit, both for tracking and energy estimation, where we designed a fully connected network that processes detector hit information. This model predicts the incoming
proton kinetic energy with sufficient accuracy for current pCT image reconstruction methods. The entire pipeline benefits from deep-learning parallelism and evaluates particle tracks fast enough for clinical time constraints. Together, these results demonstrate that compact deep learning models can reliably reconstruct particle trajectories and energies in a realistic pCT detector system, offering a computationally efficient and highly accurate alternative to traditional matching and tracking methods.
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All authors B. Dudás, G. Papp, G. G. Barnaföldi, G. Bíró
Earth and Planetary Astrophysics
CO snow lines are stabilised by the vertical transport of volatiles
Alfie Robinson, James E. Owen and Richard A. Booth
Volatile
evolution in protoplanetary discs determines the compositional
evolution of forming
planets. Below their sublimation temperatures, volatiles freeze out from the vapour phase onto
dust grains in the disc and transition to being dynamically-coupled to the
dust component as opposed to the gas. The boundary between the ice and vapour phases is referred to as the snow line, when thought of as the mid-plane radius at which the phase transition occurs, or the snow surface, when viewed as a 2D (radial and vertical) structure in the disc. We investigate whether the CO snow line (and therefore snow surface) is thermally unstable and therefore liable to changes in its location during disc
evolution using the disc
evolution code cuDisc, to which we have added an ice-vapour chemistry solver. We find that the instability does lead to there being two steady-state stable
equilibrium solutions for the snow surface when including the vertical structure. However, in dynamically-evolving simulations, the disc does not enter a limit-cycle - as seen in previous 1D models - due to the shape of the 2D snow surface and the vertical transport of volatiles. We therefore expect that dynamically
evolution of snow lines due to instability is limited to transient,
stochastic events rather than oscillatory behaviour with a regular period. However, we also expect the snow surface to evolve substantially during the disc lifetime solely due to changes in the thermal structure driven by
evolution of the
dust spatial structure and grain-size distribution - this we will explore in future models.
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Medical Physics
Physically-Constrained Harmonic Separation for Robust Heart and Respiratory Rate Estimation from Wrist Photoplethysmography
Nouhaila Fraihi, Ouassim Karrakchou and Mounir Ghogho
Wrist-worn photoplethysmography (PPG) enables continuous monitoring of cardiopulmonary physiology, but reliable heart rate (HR) and respiratory rate (RR) estimation in free-living conditions remains challenging due to non-stationary motion artifacts that spectrally overlap with physiological dynamics. Existing signal-processing methods degrade under strong motion, while unconstrained deep learning approaches often lack physiological interpretability and identifiable structure. We propose a Physically-Constrained Harmonic Separation (PCHS) framework that formulates HR and RR estimation from wrist PPG as an analysis-by-synthesis problem, where accelerometer measurements condition artifact separation rather than directly regressing vital signs. A physics-guided harmonic generator decomposes the observed signal into quasi-periodic physiological components and a motion-related residual, enabling HR recovery from the fundamental frequency and RR prediction from respiratory-driven modulations of the harmonic parameters. Robust reconstruction objectives, separation constraints, and uncertainty-aware weighting stabilize the decomposition under motion. Experiments on the motion-intensive PPG-DaLiA
dataset demonstrate that PCHS outperforms state-of-the-art methods while yielding interpretable signal decompositions that effectively disentangle physiological activity from motion artifacts.
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Plasma Physics
Fusion-power amplification by compressive hydrodynamic fluctuations
Henry Fetsch and Nathaniel J. Fisch
Compressive fluctuations in hot
plasma, including acoustic waves and compressible
turbulence, increase the rate of fusion reactions. This power amplification comprises hydrodynamic, “two-temperature,” and kinetic components, the first resulting from the clumping of hot ions in the peaks of the fluctuations, the second from the unequal heating of ions and electrons as fluctuations dissipate, and the third from the long mean free paths of fast ions near the Gamow peak, which allow these ions to stream across gradients in fluctuating hydrodynamic fields before colliding. In many cases, the increase in fusion power produced by waves exceeds that produced if the wave energy were instead used for heating. Response functions describing the modification to fusion power by compressive fluctuations are obtained in magnetized and unmagnetized fusion
plasmas. Comparison to the related shear flow reactivity enhancement effect, a kinetic mechanism that increases fusion power in some divergence-free flows, illustrates a fundamental distinction between compressible and solenoidal
turbulence in fusion
plasmas.
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Nuclear Theory
Anisotropic hadronic rescattering and its impact on $K^{*0}$ yield, and polarization observable
Kadambini Menduli and Md. Nasim
In this work, we investigate the anisotropic suppression of reconstructed $K^{*0}$ resonances arising from hadronic rescattering using the A Multi-Phase Transport (AMPT) model for Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV. We demonstrate that the rescattering probability of the decay daughters depends strongly on the decay angle $\theta^{*}$ due to Lorentz boost effects, which lead to smaller laboratory-frame momenta for daughters emitted opposite to the parent particle motion. This anisotropic suppression influences several experimentally measured observables. We show that the reconstructed $K^{*0}$ yield exhibits a strong $\theta^{*}$ dependence. Furthermore, the anisotropic loss of resonances modifies the angular distributions used to extract the
spin alignment parameter $\rho_{00}$ in the production-plane and helicity frames. Even in the absence of intrinsic polarization in the model, the reconstructed $K^{*0}$ sample shows deviations of $\rho_{00}$ from the unpolarized value of $1/3$, with opposite trends in the two reference frames. These results demonstrate that hadronic rescattering can generate apparent polarization signals and must be carefully considered in experimental measurements of vector-
meson spin alignment using production plane and helicity frame.
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Instrumentation and Detectors
Charge sharing and alignment performance of bent ALPIDEs measured with low-energy protons
Berkin Ulukutlu, Christopher Ehrich, Laura Fabbietti et al. (+14 more)
The upgrade of the ALICE experiments Inner Tracking System (ITS3) aims to replace its innermost detection layers with bent wafer-scale CMOS MAPS sensors. This study examines the performance of ALPIDE chips, currently used in the ALICE ITS2, when operated in a bent configuration under realistic experimental conditions.
Proton beams with energies of 80 MeV, 120 MeV and 200 MeV were used to study
proton-
proton elastic scattering on a polypropylene fiber target reconstructed using two opposing arms of trackers with sensors bent to radii of 18 mm, 24 mm and 30 mm. The measured low-momentum
protons provided a testbed for investigating clustering behavior in high-energy loss events, where no significant impact of bending was observed on cluster size. Additionally,
alignment strategies for bent detectors were evaluated using the distance of closest approach (DCA) and opening angle between scattered
proton tracks as
benchmarks. The achieved resolution matches expectations from simulations, confirming the suitability of bent MAPS sensors for future high-energy and
nuclear physics applications.
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All authors Berkin Ulukutlu, Christopher Ehrich, Laura Fabbietti, Roman Gernhäuser, Fabrizio Grosa, Hartmut Hillemanns, Tobias Jenegger, Alex Kluge, Lukas Lautner, Magnus Mager, Lukas Ponnath, Andrea Rossi, Isabella Sannaa, Serhiy Senyukov Johanna Stachele, Miljenko Šuljić, Laszlo Vargaa, Alperen Yüncü
General Relativity and Quantum Cosmology
Wave Optics Effects from Gravitational Wave Propagation Through Dark Matter Halos
Annamalai P. Shanmugaraj, Roland Haas, Erik Schnetter et al. (+1 more)
Gravitational wave (GW) propagation is usually studied under the
geometric optics approximation. However, when GWs propagate through structures of sizes similar to their wavelength, this approximation breaks down. To study this situation, we present a scheme for numerically evolving linearised plane GWs through stationary, spherical astrophysical structures in both weak and strong
gravity regimes. Our simulations evolve the full Einstein equations (with all 10 components) for Gaussian, NFW and Burkert potentials. Our simulations show that the scattering of the GWs depends not only on the mass of the lens but also strongly on the gravitational potential distribution of the lens. Among our most important results, we find that the GWs do not propagate along null geodesics when propagating through the Gaussian density, neither in the strong nor weak
gravity setting. Another significant finding is that in the strong
gravity case of the Burkert potential, the convexity of the wave is flipped when leaving the structure. We compare our results with the linearized scalar wave predictions and find that the difference between these and the exact GW modes are of order one when the wave is inside the central potential. However, the difference reduces to only a few percent when the wave has passed through the structure. Although these effects are small, future GW detectors and
Pulsar Timing Arrays (PTAs) could be sensitive to these signals which could thus potentially help in constraining the structure of dark matter spikes or
halos.
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All authors Annamalai P. Shanmugaraj, Roland Haas, Erik Schnetter, Sofie Marie Koksbang
Quantum Physics
Spin bath mediated long-lived coherent oscillations of NV centers in diamond
Akshat Rana, Pooja Lamba, Basanta Mistri et al. (+3 more)
Decoherence is the biggest bottleneck in all
quantum technologies. For nitrogen-vacancy (NV) centers in diamond, the loss of coherence is caused by the electron and
nuclear spin bath of the diamond
lattice. Here, we demonstrate that the
spin bath - that typically causes decoherence - entangles the
spin states of the NV electron and the host $^{14}$N
nucleus. The many-body interaction between the $^{14}$N
nucleus - electron - bath
spins at an energy level anti-crossing occurring for an applied
magnetic field orientation perpendicular to the NV axis is responsible for this effect. This is observed experimentally in NV ensembles via electron
spin-echo measurements, where the echo envelope is modulated at the frequency of a $^{14}$N
nuclear spin transition. Using numerical simulations, we show that the
spin bath coupling to the NV centers is essential for observing this modulation. Due to the zero first-order Zeeman effect at the anti-crossing, the observed oscillations have long
spin-echo coherence times, 2–3 times those at the parallel
magnetic field orientation. The oscillation frequency is highly stable and robust against environmental fluctuations. These findings provide new opportunities for fundamental studies of many-body physics and
quantum sensing.
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All authors Akshat Rana, Pooja Lamba, Basanta Mistri, Dieter Suter, Siddharth Dhomkar, Rama K. Kamineni
High Energy Astrophysical Phenomena
Joint population and strong-lensing inference for resolved gravitational-wave events probes the black-hole merger rate beyond the peak of star formation
Matthew Mould
Gravitational waves can be lensed by intervening potentials of various scales. Strong
lensing leads to underestimated distances and overestimated masses, biasing astrophysical results if not accounted for. I present a novel analysis of the LIGO-Virgo-KAGRA catalog of binary black-hole mergers, simultaneously inferring (1) whether or not each event is strongly lensed, (2) their magnifications if so, and (3) the underlying merger population, using both parametric and nonparametric population models as well as two models for the
lensing optical depth. Posterior
lensing probabilities do not exceed 1% for any event, so population constraints are consistent with those assuming nondetection of strong
lensing or that
lensing never occurs. This includes multiple subpopulations over black-hole mass and a component with high aligned
spins. Compared to standard analyses, however, there are reductions of order 10% in uncertainty on the
redshift at which the merger rate peaks and an order of magnitude in high-
redshift rate upper limits. Though modest, these are the first constraints using only resolved events at
redshifts where current ground-based gravitational-wave detectors are usually insensitive, at and beyond the peak of
star formation.
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Quantum Physics
Zeguo Wang, Quanfeng Lu, Wentao Yang et al. (+3 more)
Variational
quantum algorithms (VQAs) have emerged as a promising approach to
quantum cryptanalysis on noisy intermediate-scale
quantum (NISQ) devices. Although numerous variational attack schemes have been proposed for symmetric cryptosystems, a systematic and modular benchmarking framework to evaluate their performance is still lacking. In this work, we present a comprehensive
benchmark study of variational
quantum attacks on the Simplified Data Encryption Standard (S-DES), focusing on the modular design choices that determine attack efficiency. We formulate variational
quantum attacks within a unified framework consisting of four components: initial state preparation, parameterized
circuit (Ansatz) design, cost function construction, and classical optimization. Through numerical simulations, we systematically compare representative design alternatives and evaluate their combinations in terms of convergence behavior, success probability, and effective time complexity. We further introduce standardized metrics for assessing variational
quantum attack performance. Our results reveal clear performance hierarchies among different modular configurations and show that carefully optimized designs can significantly outperform naive
quantum search. This work establishes a principled
benchmark methodology for variational
quantum cryptanalysis and positions S-DES as a practical testbed for evaluating
quantum attacks on symmetric ciphers in the NISQ era.
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All authors Zeguo Wang, Quanfeng Lu, Wentao Yang, Shijie Wei, Gui-Lu Long, Kai Wen
High Energy Astrophysical Phenomena
Optimising transient discovery with Swift-XRT
S. Srivastava, P. A. Evans, M. R. Goad et al. (+1 more)
The Living Swift-XRT Point Source Catalogue (LSXPS) enables near real-time searches for X-ray transients. Many detected candidates are faint, often near the XRT detection limit, and are classed as "low significance," as it is often unclear whether their apparent brightening reflects a genuine transient or a statistical fluctuation. Some of these sources are affected by Eddington bias, a statistical effect that inflates measured fluxes near the detection threshold. We present a simulation-based
Bayesian framework that corrects for this bias and provides more accurate probabilities for each source being truly transient, i.e. that its true intensity exceeds the historical 3$\sigma$ upper limit. Applied to LSXPS data, this method yields more reliable classifications, recovering over 500 transients above this threshold – more than an eight-fold increase over the original confirmed sample. Using extensive simulations based on real Swift-XRT images, we validate the robustness of this approach, showing that it remains stable across varying exposure times and background conditions. These results demonstrate that the LSXPS transient probabilities, corrected for Eddington bias, provide a reliable and internally consistent framework for real-time X-ray transient identification.
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All authors S. Srivastava, P. A. Evans, M. R. Goad, R. A. J. Eyles-Ferris
High Energy Physics (Phenomenology)
Feasibility study of light sterile neutrino searches with a future NINJA-like detector
Doris Barčot, Tsutomu Fukuda, Monojit Ghosh et al. (+8 more)
In this paper, we investigate the sensitivity of future NINJA-like experiment at J-PARC to eV-scale sterile
neutrinos within the 3+1 framework. We perform a phenomenological feasibility study using the $\nu_\mu \rightarrow \nu_e$ appearance, $\nu_\mu \rightarrow \nu_\mu$ and $\nu_e \rightarrow \nu_e$ disappearance channels, focusing on possible future configurations of the detector located at different floors of the NM building (B2, SS, and GROUND), corresponding to different off-axis angles. Our analysis is based on a simplified and effective detector response, in which events are classified into electron-like and
muon-like
topologies and constant
benchmark selection efficiencies are applied. We explore different exposure scenarios and assess the impact of analysis choices such as upper energy cuts. We include systematic uncertainties corresponding to normalization for signal and background rates and study the robustness of our results with respect to variations in the assumed energy resolution, and vary efficiencies for key backgrounds such as
muon misidentification from charge current and neutral current interactions. Finally, we examine the effects of combining data from multiple detector locations. We find that the SS floor provides the strongest constraints on the active-sterile mixing parameters, while the B2 and GROUND configurations offer constraints comparable to the current bounds for probed mass-squared differences. Our results indicate that a NINJA-like detector, optimized for sufficient statistics and
benchmark identification performance, has the potential to provide competitive constraints on light sterile
neutrino scenarios in its future runs.
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All authors Doris Barčot, Tsutomu Fukuda, Monojit Ghosh, Leon Halić, Mahesh Jakkapu, Teppei Katori, Budimir Kliček, Masahiro Komatsu, Tomokazu Matsuo, Osamu Sato, Atsumu Suzuki
Solar and Stellar Astrophysics
Far-ultraviolet flux distribution in Orion and its relation to stellar accretion
Rossella Anania, Andrew J. Winter, Miguel Vioque et al. (+8 more)
Orion is the closest region hosting active
star formation and young OBA
stars. Computing far-ultraviolet (FUV) fluxes at its
stars is essential to connect
stellar and protoplanetary disc properties to the environment. We (1) accurately estimated the FUV flux at a large sample of
stars in Orion by statistically accounting for the uncertainty in parallax measurements, and (2) investigated the relation between
stellar accretion and external FUV flux by comparing observations and disc
evolution models. We selected a large
stellar population in Orion, assigned sub-cluster memberships and used 2D dimensional sub-cluster geometry to infer 3D separations from OBA
stars and compute the FUV flux at
stellar positions. We studied the
accretion luminosities Lacc inferred from Ha emission in
Gaia XP spectra of Orion sources and determined their detection fraction as a function of age and FUV flux. We compared the results with population synthesis models of viscous discs experiencing external photoevaporation. We provided a publicly available table of FUV fluxes at ~8600
stars in Orion. Most of the
stellar population is weakly irradiated <10^{2} G0, ~35% is intermediately irradiated 10^{2}-10^{4} G0, and ~5% has FUV fluxes >10^{4} G0.
Gaia-based Lacc decreases with age, and Ha detection fraction declines more rapidly in regions with strong FUV fluxes than in regions exposed to weaker FUV fluxes, broadly consistent with the model. This may suggest that external photoevaporation efficiently depletes strongly FUV-irradiated
accretion discs, but it is not sufficient to reliably confirm this conclusion. The provided tools for computing FUV fluxes at Orion
stars will be essential for future observations aimed at assessing the role of external photoevaporation on discs. We encourage measurements of
stellar and disc properties in Orion, covering FUV fluxes 1-10^5 G0.
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All authors Rossella Anania, Andrew J. Winter, Miguel Vioque, Giovanni P. Rosotti, Giacomo Beccari, Giuseppe Lodato, Lorenzo A. Malanga, Lara Piscarreta, Alice Somigliana, Leonardo Testi, Claudia Toci
Mathematical Physics · Cross-listed from math.NT
On the diffraction spectrum of the set of visible points in lattices and certain cut-and-project sets
Rishi Kumar and Carlos Ospina
Let $k\geq 2$ be a positive integer. It is known that the set of visible
lattice points from the origin in $\mathbb{Z}^k$ has a translation bounded pure point diffraction spectrum. We investigate these properties for sets of points simultaneously visible from a finite set of
lattice points $ \{\mathbf{x}_1,\dots,\mathbf{x}_n\} \subseteq \mathbb{Z}^k$. We provide explicit formulas for the coefficients of the diffraction spectrum. Additionally, we generalize our procedure to show that the set of visible points from the origin in certain classes of cut-and-project sets has a translation bounded pure point diffraction spectrum.
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Astrophysics of Galaxies
The Impact of Non-Gaussian Line Spread Functions on Stellar Kinematic Recovery: Consequences for Dynamical Models
David A. Simon
The line spread function (LSF) of a spectrograph encodes the inherent broadening of a single spectral line. It is typically reported as a single number, the resolving power $R = \lambda/\Delta\lambda$ with $\Delta \lambda$ the FWHM of the LSF. In standard pipelines for extracting
stellar kinematics the LSF is assumed to be a wavelength dependent Gaussian. However, detailed LSF measurements from real integral field spectrographs reveal a variety of shapes, some close to Gaussian, others with large wings or that appear boxy. I have studied the impact that these non-Gaussian LSF profiles have on the recovery of the
stellar kinematics of a mock spectrum based on MUSE ($\sigma_{\rm inst} = 51 $ km s$^{-1}$) and find that even in the high dispersion case of 300 km s$^{-1}$, there is up to a 7 percent bias in the dispersion due to non-Gaussian LSF profiles. Additionally, higher order Gauss-Hermite moments $h_3$ and $h_4$ can be biased by up to $\pm$0.1. To resolve this bias, I developed a method to match the LSF of the template spectra to the LSF of a target spectrum when the LSF of either one or both is non-Gaussian and show that it can reduce bias in the dispersion to less than a percent down to the instrumental resolution. A Python implementation of this method has been made publicly available.
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Geophysics
Seismic full waveform inversion via a physics-guided Fourier representation neural network
Gui Chen, Yang Liu, Haoran Zhang et al. (+1 more)
Accurate subsurface velocity models are essential for seismic imaging, yet conventional full waveform inversion (FWI) often suffers from cycle skipping, noise sensitivity, and reliance on good initial models. We develop a physics-guided
Fourier representation neural network (PGFRNN) for unsupervised acoustic FWI and simultaneous-source FWI (SSFWI), which embeds
Fourier-transformed seismic data into a latent space and iteratively updates the velocity model using a softplus-approximated log-cosh (SALC) loss and a physics-guided optimizer. Numerical tests on the Overthrust model demonstrate that PGFRNN outperforms conventional L2- and SALC-loss-based FWI methods, achieving higher inversion accuracy and robustness to noise and challenging initial models.
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All authors Gui Chen, Yang Liu, Haoran Zhang, Mi Zhang
Materials Science
Ferroelastic domain wall motion and collective domain switching in RbSCN
V. Soprunyuk, A. Tröster, J. Pils et al. (+4 more)
Low frequency (0.05 - 40 Hz) dynamic elastic measurements and resonant ultrasound spectroscopy measurements (100-600 kHz) of RbSCN have been performed in the temperature region of the order-disorder improper ferroelastic phase transition at T$_c \approx$ 435~K. Quite similar to KSCN, the low frequency data show - in addition to the intrinsic phase transition anomalies - superelastic softening in a- and b-directions, resulting from movements of ferroelastic domain walls under dynamic stress. However, in contrast to KSCN, a sudden discontinuous increase of Young's modulus appears in RbSCN at { T$^{\ast} < T_c $}, which is accompanied by a frequency dependent damping peak. This behaviour is reminiscent of a first order phase transition.\\ Heating RbSCN slightly above T$^{\ast}$, followed by subseqent cooling, removes all {signs of domain wall dynamics}. The results demonstrate, that the anomalies in RbSCN around $T^{\ast}$ result from collective domain switching events that are induced when the {temperature dependent critical pinning stress, $\sigma_c(T)$ falls below the applied external stress $\sigma$, implying that $T^{\ast}(\sigma=\sigma_c)$. This interpretation is supported by calculations of the temperature dependences of twin boundary widths $w$ and energies $F_w$, as well as the Peierls potential $V_0$ using a compressible pseudospin model, which leads to a critical pinning stress, $\sigma_c(T)$ that is in excellent agreement with experimental values of $T^{\ast}(\sigma_c)$. }
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All authors V. Soprunyuk, A. Tröster, J. Pils, W. Schranz, I. Rychetsky, A. Klic, M.A. Carpenter
Plasma Physics
Kinetic energy from the cubic sum rule of the dynamic structure factor
Fotios Kalkavouras, Panagiotis Tolias, Sebastian Schwalbe et al. (+6 more)
The third frequency moment sum rule of the dynamic structure factor $S(\mathbf{q},\omega)$ is explored for the first time as an alternative
estimator of the kinetic energy $K$ of
quantum many-body systems. As a practical example, the uniform electron gas at warm dense matter conditions is considered. First, $K$ is extracted from quasi-exact ab initio path integral Monte Carlo results for the imaginary-time density–density correlation function $F(\mathbf{q},\tau)$ and the expected excellent self-consistency with the thermodynamic differentiation route is confirmed. Second, $K$ is extracted from approximate dielectric formalism results for $S(\mathbf{q},\omega)$ and it is observed that common semi-classical approximations lead to a wave-number dependent $K$ with an incorrect short-wavelength limit. Our results are expected to be of broad interest for a great variety of applications, including time-dependent density functional theory, dielectric formalism schemes and warm dense matter models, as well as for the design of dedicated x-ray Thomson scattering experiments with the potential to provide model-free access to the full electronic equation of state.
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All authors Fotios Kalkavouras, Panagiotis Tolias, Sebastian Schwalbe, Thomas Gawne, Alexander Benedix Robles, Jan Vorberger, Zhandos Moldabekov, Maximilian Böhme, Tobias Dornheim
High Energy Physics (Theory)
Gravitational Duals from Equations of State II: Large Hierarchies and False Vacua
Raul Jimenez, David Mateos, Pavlos Protopapas et al. (+3 more)
We investigate the reconstruction of
holographic duals for strongly coupled
quantum field theories in regimes characterized by large hierarchies and the presence of false
vacua. Within the gauge/
gravity duality, these features translate into non-trivial thermodynamic behaviour and exotic renormalization group flows, including skipping flows between non-adjacent fixed points. Building on previous work based on Physics-Informed Neural Networks (PINNs), we extend the
holographic inverse problem of reconstructing the bulk scalar potential from boundary thermodynamic data into this new regime. This setting presents a variety of conceptual and numerical challenges, such as near-degenerate states, large hierarchies of energy scales, and regions of the potential that are not directly probed by the input data. We develop a set of methodological advances that overcome these obstacles, thereby improving the established PINNs-based methodology and extending it to new physical regimes of interest that were previously out of reach. Applying the developed framework, we demonstrate accurate reconstruction of scalar potentials deep into the false
vacuum regime, achieving robust agreement with the physical features of the underlying thermodynamics despite significant numerical stiffness. Our results extend the bridge between holography and machine learning, and suggest that data-driven approaches can provide new insights into the structure of strongly coupled systems.
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All authors Raul Jimenez, David Mateos, Pavlos Protopapas, Pau Solé-Vilaró, Pedro Tarancón-Álvarez, Pablo Tejerina-Pérez
Medical Physics
Adversarial robustness of a U-Net-based model observer for CT protocol optimization
Filippo Maria Balli, Giorgia Stendardo, Sandra Doria et al. (+6 more)
Artificial intelligence is increasingly used in medical imaging, yet its robustness to input perturbations remains a critical concern for a wide clinical adoption. To this end, we used
adversarial examples to systematically probe vulnerabilities of a U-Net-based model observer for computed
tomography protocol optimization, performing detection and localization of low-contrast objects in a phantom
dataset.
Adversarial attacks were generated using both gradient-based and optimization-based white-box methods. Fast gradient perturbations produced high misclassification rates, reaching up to 75% at intermediate perturbation levels while remaining visually imperceptible. Localization was more robust, with success rates of about 25% for small perturbations and 42% at moderate levels. In contrast, optimization-based attack achieved success rates close to 50% for both tasks. To mitigate these vulnerabilities, dynamic
adversarial training was implemented. This reduced the success rate of optimization-based attacks to 7% for classification and 13% when including localization-specific training, demonstrating a substantial robustness improvement without compromising task performances, confirmed by localization receiver operating characteristic analysis. To further interpret model behavior, radiomic texture analysis was performed on original and
adversarial images. While most global image statistics remain stable, specific texture-related features exhibit consistent changes in successful attacks, highlighting the model's sensitivity to subtle local intensity patterns. Overall,
adversarial training improves robustness without degrading performance, while radiomic analysis reveals interpretable links between texture alterations and prediction failures, supporting more reliable and explainable AI systems for medical imaging.
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All authors Filippo Maria Balli, Giorgia Stendardo, Sandra Doria, Michele Ginolfi, Alessio Gnerucci, Diego Sona, Adriana Taddeucci, Cesare Gori, Evaristo Cisbani
Solar and Stellar Astrophysics
Asymmetric nightside CO2 features, inefficient heat transport, and precise evolutionary constraints: Spectroscopic phase curves reveal the past and present of a white dwarf-brown dwarf binary
Daphne Broski-Laing, Yifan Zhou, Joshua D. Lothringer et al. (+10 more)
We present the first JWST phase curve of a white
dwarf-brown
dwarf binary, a NIRSpec PRISM observation of ZTFJ0038+2030. Short-period white
dwarf-brown
dwarf binaries provide unique laboratories to probe substellar atmospheres.
Tidal locking drives hot Jupiter-like atmospheric dynamics in the brown
dwarf. The system's formation history offers a window into planetary systems around post-main-sequence
stars. We obtain a full-orbit phase curve of ZTF0038, including a total eclipse of the white
dwarf, which enables us to separate the two components' emission throughout the entire orbit, and we model the brown
dwarf's phase-resolved emission spectra using substellar atmosphere forward models and atmospheric
retrievals. The PRISM spectrum covers ~80% of the brown
dwarf's bolometric emission, enabling a nearly model-independent energy balance calculation, which yields a day-to-nightside heat transport efficiency of <10%. Inefficient heat redistribution is further supported by the phase curve shape and the nightside spectrum closely resembling non-irradiated mid-to-late T
dwarfs. The spectroscopic phase curves reveal a stark nightside asymmetry associated with a strong CO2 absorption feature at 4.2 um, while the retrieved abundances indicate a longitudinally homogeneous distribution of CO2 as well as all other key species detected in the atmosphere. The precise internal luminosity measurement of the brown
dwarf informs both the age of the WD-BD system (7.5-8.8 Gyr) and indicates a low common-envelope ejection efficiency. These data illustrate the exquisite opportunity to probe the three-dimensional processes of substellar atmospheres, connect substellar and
exoplanet atmospheres, and probe the
evolution of post-main-sequence planetary systems using WD-BDs.
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All authors Daphne Broski-Laing, Yifan Zhou, Joshua D. Lothringer, Daniel Apai, Jenni R. French, Sarah L. Casewell, L. C. Mayorga, Lael Shin, Ben W. P. Lew, Xianyu Tan, Vivien Parmentier, Siyi Xu, Mark S. Marley