Nuclear Theory
The $\Sigma N$ threshold structure in the $K^-d\to\pi^-\Lambda p$ reaction
Shunsuke Yasunaga and Daisuke Jido
The $\Lambda p$ invariant-mass spectrum near the two physical $\Sigma N$ thresholds in the $K^-d\to\pi^-\Lambda p$ reaction is studied as a probe of the low-energy $\Sigma N$ interaction. The reaction is formulated up to two-step processes, and the coupled $\Lambda p$, $\Sigma^+n$, and $\Sigma^0p$ channels are described within a constant-$K$-
matrix model constrained by
spin-triplet scattering lengths. The dependence of the $\Sigma N\to\Lambda p$ conversion amplitude on these scattering lengths is examined, and the relation between its line shape and nearby pole positions is investigated. The resulting invariant-mass spectra are studied at different incident kaon momenta and compared qualitatively with existing experimental data. The effects of the
spin-singlet $YN$ amplitude and the deuteron wave function are also examined. The line shape near the $\Sigma N$ thresholds is found to be particularly sensitive to the complex
spin-triplet $I=1/2$ $\Sigma N$ scattering length, indicating that measurements of this spectrum can provide useful constraints on the low-energy $\Sigma N$ interaction.
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Nuclear Theory
Higher-order corrections to beta decays and nuclear structure
Grigor Sargsyan and Ayala Glick-Magid
Precision measurements of nuclear $\beta$ decay offer a powerful route to tests of physics beyond the Standard Model, but interpreting measurements spectra and correlation observables requires control of subtle nuclear-structure effects. This chapter develops a framework for calculating higher-order corrections–small contributions that can become important at the precision sought in searches for new interactions. After motivating their role in $\beta$-decay observables (with radiative corrections treated in the accompanying chapter), we introduce the relevant kinematics and multipole expansion of the shape factor, identify the subleading contributions, and present the impulse-approximation multipole operators. We then describe the nuclear many-body methods used to obtain the required states and transition densities, and derive the corresponding operator
matrix elements in the harmonic-oscillator basis. Taken together, these ingredients enable systematic calculations of nuclear shape factors beyond the long-wavelength approximation, including higher-order multipoles where needed. By helping distinguish Standard-Model recoil effects from possible signatures of new physics, this framework supports the interpretation of increasingly precise $\beta$-decay experiments.
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High Energy Physics (Experiment)
RINO: Renormalization Group Distillation with No Labels
Zichun Hao, Raghav Kansal, Abhijith Gandrakota et al. (+6 more)
Supervised machine learning in high-energy physics (HEP) requires training on labeled simulations of particle collisions, which are known to be unfaithful to the underlying physics. This leads to significant inaccuracies and biases in the transfer of trained models to real data, limiting the power of deep learning methods. Self-supervised learning (SSL) is a promising alternative for pretraining directly on real, unlabeled data. However, existing techniques largely operate with inductive biases inspired by domains such as images and natural
language. We propose RINO (Renormalization Group
DIstillation with NO Labels), which, for the first time, exploits the fundamentally multi-scale renormalization group structure of high-energy jet formation as a physically grounded source of SSL views. We define teacher-student representations across energy scales using different levels of hierarchical clustering, aligned via DINO-style self-
distillation. To mirror the background-dominated nature of real
collider data, RINO pretrains exclusively on jets from
quantum chromodynamics (QCD) processes and is evaluated on out-of-distribution (OOD) transfer to rare signal classes. In our controlled data-efficiency study, RINO matches fully supervised training on JetNet after finetuning on only 1% of the labeled data. With the full labeled
dataset, RINO improves OOD classification accuracy on top-
quark jets by 5.9% and, without retraining, improves AUC on the unseen
Higgs boson decay channel $H \to 4q$ by 4.1% over the strongest SSL baseline. Scale-structure diagnostics reveal that DINO-style self-
distillation permits our backbone to retain scale-dependent structure. Ablation studies show that this accounts for an 8.6% OOD accuracy gap with respect to alternative SSL paradigms such as SimCLR. Code is available at https://github.com/zichunhao/RINO.
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All authors Zichun Hao, Raghav Kansal, Abhijith Gandrakota, Chang Sun, Haoyang Li, Zihan Zhao, Ngadiuba Jennifer, Javier Duarte, Maria Spiropulu
High Energy Physics (Theory)
Random wave chaos on momentum-fractionated microstate geometries
Vladan Djukić and Mihailo Čubrović
We study the role of momentum fractionation in the development of chaos on smooth 3-charge supergravity solutions of D1-D5 theory, specifically momentum-fractionated superstrata. We probe the chaos through the dynamics of null geodesics and waves. On fractionated backgrounds, both geodesics and waves show uniformly strong chaos (large chaotic sea and near-perfect agreement with the Berry random wave hypothesis). In contrast, geodesics and waves on single-mode (non-fractionated) superstrata are closer to separability (although still chaotic). We discuss a possibility that such dichotomy can be related to the expectation that monotone BPS states are less chaotic than fortuitous ones. Finally, we explain why our chaos probes are meaningful for microstate geometries even though they become trivial in the black hole limit.
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High Energy Physics (Theory)
Microscopic entropy of regular BTZ black holes in 3d Lovelock gravity at all orders
Hikmet Özşahin
We give a microscopic derivation of the semi-classical
entropy of the black holes of 3d Lovelock
gravity with an infinite tower of regularized Lovelock corrections, which include the regular BTZ black holes found recently. Working in the mini-superspace formalism, we show that the reduced action and its boundary term can be obtained in closed form at all orders in terms of the generating function of the couplings. Assuming the ground state is described by the
soliton obtained from the static black hole by a double Wick rotation, we compute the
soliton mass and reproduce the semi-classical
entropy from the Cardy formula without central charges for arbitrary couplings. We then extend the mini-superspace to stationary configurations, compute the mass and the angular momentum of the rotating black holes obtained by a boost, and verify the Cardy formula in the presence of rotation.
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Instrumentation and Methods for Astrophysics
The Simons Observatory: Frequency-resolved beam calibration for the SO SATs with POLOCALC
Nadia Dachlythra, Gabriele Coppi, Ludovico Bizzarri et al. (+30 more)
We present a far-field beam calibration of the Simons Observatory (SO) Small Aperture
Telescopes (SATs) using scanned single-frequency measurements of a drone-mounted source emitting in the 90 GHz band, where the SATs have an angular resolution of $\sim$30$'$. We then compare the results from two campaigns in April and December 2025 to the band-averaged beams from
planet observations by the SATs. Measuring the
telescope beam response at different frequencies across the observing bands enables modeling the system's frequency-dependent behavior. This helps track optical non-idealities. The comparison with
planet beams informs the frequency resolution necessary to accurately reconstruct the band-averaged beams in this way; it uses only the average drone and
planet products, as it is intended to demonstrate the feasibility of the frequency-resolved calibration scheme rather than to set the precise beam covariance and instrument requirements. We find that the beams of the two SATs near 90 GHz follow the frequency scaling expected for diffraction-limited optics, with only modest deviations observed in the nearest lobes of one
telescope. We establish consistency between the real band-averaged
planet beams and the synthesized drone band-averaged beams for the center wafers of both
telescopes, with an average deviation smaller than 4% for multipoles $\ell < 500$.
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All authors Nadia Dachlythra, Gabriele Coppi, Ludovico Bizzarri, Federico Nati, Alessandro Novelli, Elle C. Shaw, Samuel Day-Weiss, Federico Astori, Susanna Azzoni, Dillon J. Bass, Artem Basyrov, Federico Cacciotti, Rolando Dünner Planella, Nicholas Galitzki, Remington Gerras, John C. Groh, Jon E. Gudmundsson, Saianeesh K. Haridas, Kathleen Harrington, Carlos Hervías-Caimapo, Bradley R. Johnson, Brian Keating, Adrian T. Lee, Anto I. Lonappan, Noemi Mezzanzanica, Lyman Page, Giulia Rancati Cattaneo, Sara M. Simon, Thierry Souverin, Yoshinori Sueno, Edward J. Wollack, Kyohei Yamada, Mario Zannoni
High Energy Physics (Phenomenology)
Testing Minimal $U(2)^3$ Right-Handed Flavor Breaking in a Singlet-Scalar Vector-Like Quark Portal
Qazi Maaz Us Salam
We study a portal of a $Z_2$-odd singlet scalar and a vector like down
quark, in which a right handed flavor breaking spurion extends the portal coupling from $b_R$ to $d_R$ and $s_R$. This single coupling vector links the $b\to s$, $b\to d$, and $s\to d$ transitions. We compute the one loop dipole and $\Delta F=2$ Wilson coefficients, and show that a real scalar generates no $\Delta F=2$ amplitude at one loop. Using a seven observable profile likelihood of $B$
meson mixing, $\epsilon_K$, and radiative decays, with the CKM,
lattice, and short distance inputs treated as nuisance parameters, we compare a generic spurion, minimal $U(2)^3$ with a free size of the light
quark couplings, and a CKM-aligned ansatz. We have found that the present data cannot yet test the flavor structure: the Standard Model is compatible with the data, with a pseudo experiment $p$-value of $0.20$, and no direction of the light
quark couplings can be excluded at 95% CL. For $M_D\simeq m_{\mathcal{S}}=1$ TeV and $|\lambda_b|=1$, the relative light
quark coupling $\epsilon_R$ is bounded at 95% CL by $0.227$ for a generic spurion and by $0.211$ for minimal $U(2)^3$. More precise measurements of the $B_s$ mixing phase at the LHC and of $\sin2\beta$ at LHCb and Belle-II, together with improved
lattice and CKM inputs, can make the minimality of the flavor structure testable if a deviation from the Standard Model is observed.
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Quantum Physics
Quantum limit cycles from phase coupling: A framework for NISQ thermodynamic devices
Nana Siddhartha
Quantum decoherence does not permit the operation of (new) miniaturised devices or protocols that can otherwise run unassisted in classical settings, without explicit user
agent intervention in the
quantum realm. Classical driving signals are inadequate to model a truly
quantum device built entirely in the
quantum realm. Synchronisation endures miniaturisation without sacrificing
quantum coherence, unlike thermalisation. We quantise the Kuramoto model and the Van der Pol oscillator and couple it with
qubit(s) to show a robust limit cycle even in typical
quantum thermodynamical settings. Novel effects such as
Entanglement State Revivals, Zeno locking and thermal current interference are observed. We propose toy model devices that can be implemented harnessing the Synchronisation of a
qubit (or an arbitrary collection of
qubits) with a nonlinear phase oscillator. The framework theory used here, Spectral Mechanics, is a fresh look at the foundations of conventional
quantum mechanics and is extensible to completely new forms of interactions and models in experimental settings.
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Optics
Transfer learning-aided, artificial intelligence approach to evaluate optical properties of materials for classical and quantum photonic applications
Mohammad Reza Habibi, Luca Sapienza and Juan C. Vasquez
In this study, an artificial intelligence-assisted evaluation of the refractive indices of different materials is performed. The evaluation of the refractive index is necessary to design photonic devices for various classical and
quantum photonic applications, and to theoretically analyse experimental results. The refractive index is one of the crucial parameters that affect the interaction of light with matter. Although the refractive index can be measured experimentally, its estimation via computational means provide the advantage of not requiring costly instrumentation, trained researchers and could avoid potential laboratory-based uncertainties. Therefore, in this study, artificial intelligence is implemented to estimate the optical constants of two types of materials, i.e., noble metals, and
semiconductors. To this end, an artificial neural network is used to estimate the real and the imaginary parts of the refractive index of a specific material for various wavelengths of light. Then, the knowledge of the trained neural network is employed to initiate and train new neural networks to estimate the refractive indices of other materials. For the training of a neural network, various methods can be deployed. However, the application of the training can be a time-consuming process. A transfer learning approach is here implemented to provide a faster training solution for the problem under study. The implementation of transfer learning allows training the neural networks for a new material with higher speed or accuracy when compared to non-knowledge transfer-based training. Our results show the efficiency of the proposed technique in accurately evaluating the real and imaginary parts of the refractive index of different materials.
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Astrophysics of Galaxies
The DAWN JWST Archive: A spectroscopically-informed population study of the physical properties of galaxies at z>2
Rashmi Gottumukkala, Gabriel Brammer, Sune Toft et al. (+30 more)
Charting the
evolution of
star-formation, stellar mass and dust build-up over
cosmic time relies on the accurate characterisation of the stellar population properties of high
redshift galaxies. We present a catalogue of spectroscopically derived physical properties for ~12,000
galaxies at z>2, with archival JWST/NIRSpec PRISM spectroscopy and JWST/NIRCam imaging from the DAWN JWST Archive. We present a custom version of the SED fitting code BAGPIPES, used to perform joint spectrophotometric modelling of PRISM spectra and broadband NIRCam photometry. In doing so, we publicly release a science-ready catalogue of the physical properties of
galaxies beyond
cosmic noon. We report key physical properties, such as stellar masses,
star-formation rates (SFR) and timescales, and V-band dust attenuation (Av). We further probe the recent
star-formation histories (SFH) of
galaxies via their SFRs on 3 Myr, 10 Myr, and 100 Myr timescales, capturing both rising and falling recent SFHs. Through dust-corrected ugi colour-colour diagrams of massive
galaxies, we show how quiescent and dusty
galaxies populate this colour space at z>2, with
galaxies experiencing a recent downturn in
star-formation occupying distinct parameter space. We also study the dustiest
galaxies in our sample, showing that they are preferentially more massive and strongly
star-forming relative to the parent sample, residing on the high-mass end of the
star-forming main-sequence. The slope of the attenuation curve has a strong dependence on Av, varying from steep to shallow as the dust attenuation increases and the specific
star-formation rate decreases. Our findings show that the unparalleled number statistics of this catalogue of spectroscopically derived stellar population properties uniquely enables the study
star-formation, quenching and dust properties of
galaxies from
cosmic noon to
cosmic dawn.
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All authors Rashmi Gottumukkala, Gabriel Brammer, Sune Toft, Mengyuan Xiao, Anna de Graaff, Pascal A. Oesch, Francesco Valentino, Katherine E. Whitaker, William M. Baker, Laia Barrufet, Rachel Bezanson, Leindert A. Boogaard, Alex J. Cameron, Olivia R. Cooper, Emma Giovinazzo, Kasper E. Heintz, Michaela Hirschmann, Kei Ito, Ivo Labbe, Minju M. Lee, Zach J. Lewis, Jorryt Matthee, Ian McConachie, Desika Narayanan, Clara L. Pollock, Sedona H. Price, David J. Setton, Marko Shuntov, Pieter van Dokkum, Bingjie Wang, Joris Witstok, Yunchong Zhang, Pengpei Zhu
Optics
Simultaneous Recovery of Dielectric Constants, Photoelastic Constants, and Strain Profiles from Picosecond Ultrasonic Echoes
Richard Wiltshaw, Motonobu Tomoda, Osamu Matsuda et al. (+3 more)
Light reflected from a deforming solid depends on boundary motion and strain-induced modulation of the dielectric response. For a propagating acoustic field, scattering from different depths interferes coherently, so the measured optical amplitude and phase depend jointly on the strain profile, dielectric constant, and photoelastic constant. Optical
tomography often makes such reconstructions tractable through independent projections. To probe mechanical strain, however, the optical measurement also depends on the material properties that mediate its observation, requiring those properties to be known or assumptions about the field. Here we show that broadband picosecond ultrasonic echoes in an opaque solid can supply the missing information.
Fourier transformation of the measured complex relative reflectance change obtained with monochromatic light at normal incidence gives access to many acoustic frequency components. We recover the complex dielectric and photoelastic constants together with the nanoscale depth-dependent strain profile by formulating the reconstruction as a multiparameter nonlinear
eigenvalue problem. We demonstrate the method using experimental echoes from a chromium film. The recovered refractive index agrees with ellipsometry, whereas the recovered strain profile closely follows a two-temperature-model prediction including electron and thermal
diffusion and frequency-dependent ultrasonic attenuation. Synthetic echoes test robustness to added noise. Broadband response thus replaces additional optical projections, making the measurement self-calibrating and enabling simultaneous recovery of an unknown physical field and the material properties that mediate its optical observation.
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All authors Richard Wiltshaw, Motonobu Tomoda, Osamu Matsuda, Takehiro Tachizaki, Hirotsugu Ogi, Oliver B. Wright
Solar and Stellar Astrophysics
Assessing the impact of background subtraction on a dust-free corona
Erika Palmerio, Cooper Downs, Phillip Hess et al. (+4 more)
Context. White-light observations of the solar corona contain contributions from both the electron-scattered K-corona and the dust-scattered F-corona. Because the diffuse F-corona dominates the measured intensity at altitudes of approximately 4 $R_{\odot}$ and above, background subtraction techniques are routinely employed to isolate the electron corona in coronagraph observations. Aims. Since no direct observational "ground truth" for the K-corona exists, the amount of coronal signal that is inadvertently removed by background subtraction methods remains unknown. We aim to quantify, for the first time, the impact of background subtraction on the inferred large-scale structure and brightness of the solar corona. Methods. We use a 32-day simulation based on a novel near-real-time, data-assimilative, time-evolving magnetohydrodynamic model to generate synthetic white-light observables. Because these synthetic observations are free from dust and instrumental stray-light contributions, they provide direct access to the "true" K-corona and enable a quantitative assessment of the effects of background subtraction. Results. We find that background subtraction generally preserves the large-scale morphology of the electron corona, including the locations and shapes of major coronal structures. However, the procedure systematically modifies the relative brightness of different features and removes a non-negligible fraction of the K-coronal signal. Conclusions. Although standard background subtraction techniques successfully recover the overall appearance of the electron corona, they can alter its quantitative photometric properties. These findings should be considered when interpreting coronal brightness measurements and deriving physical properties from processed white-light observations.
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All authors Erika Palmerio, Cooper Downs, Phillip Hess, Benjamin J. Lynch, Ryder Davidson, Ronald M. Caplan, Jon A. Linker
Quantum Physics
Local-dimension-invariant low-density parity-check stabilizer codes
Md. Shahinul Islam, Aaryan Reza and Lane G. Gunderman
The protection of
quantum information in systems leveraging more than two basis states (qudits) is an ongoing challenge. A tool for transforming the plethora of
qubit stabilizer codes into qudit stabilizer codes is the local-dimension-invariant (LDI) extension to the stabilizer formalism. A drawback of the LDI method is that generally in order to ensure the distance of the resultant code is at least preserved the newly selected local-dimension will need to be any
prime bigger than a large cutoff value. In this work we consider the repercussions of this large cutoff value, then by focusing on
quantum low-density parity-check (qLDPC) codes we are able to bring down this cutoff value. Notably, we are able to reduce it in some cases to the initial local-dimension and for arbitrary CSS
qubit-derived codes to singly exponential in $d$ with no dependence on the number of logicals $k$. This reduces the size of the caveat in LDI forms in their distance preservation condition.
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High Energy Physics (Theory)
From Lyapunov Growth to Weak Quantum Chaos
Sašo Grozdanov and Tomaž Prosen
Local out-of-time-order correlators (OTOCs) measure the growth of initially small commutators. For bounded local operators, this growth ends when the local commutator becomes of order one, but in an extended system the region over which it is large can continue to expand. We study this spatial proliferation using three related observables: the local squared commutator $C_r(t)$, its spatial sum $\bar C(t) = \sum_r C_r(t)$, and the symmetrically regularised connected dOTOC $D(t)$ of two extensive observables. We show that Lieb–Robinson locality gives $\bar C(t) \lesssim t^d$. We then prove that, in a Gibbs state with uniform exponential clustering, the full dOTOC obeys the same bound, $D(t) \lesssim t^d$, improving our earlier suboptimal $t^{3d}$ bound. We illustrate these results in two
quantum many-body systems: a Brownian coupled-cluster model and a finite-temperature SYK chain. In both cases, an exact disorder
symmetry relates $D(t)$ to $\bar C(t)$ and allows us to follow the same extensive observable from the pre-scrambling Lyapunov regime into the post-scrambling growth associated with an expanding saturated region. This late-time power-law growth is the concrete realisation of the weak
quantum chaos introduced in our earlier work.
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Quantum Physics
End-to-End Fidelity and Rate Analysis for Zero-Added-Loss Multiplexing
Jeffrey H. Shapiro
Zero-added-loss multiplexing (ZALM)~[Phys. Rev. Appl. 19, 054029 (2023)] is a midpoint-source scheme for
entanglement distribution. Its
quantum transmitter (QTX) employs two Sagnac sources of polarization-entangled pairs plus partial Bell-state measurements (BSMs) on their idler outputs to herald
entanglement in their signal outputs, thus avoiding the switching losses suffered by other multiplexing approaches. When its Sagnac sources' spontaneous parametric downconverters (SPDCs) utilize $\chi^{(2)}$
crystals with phase-matched spectral islands, ZALM avoids the tradeoff between heralding efficiency and output-state fidelity incurred when conventional-
crystal SPDCs' outputs are channelized by dense wavelength-division multiplexing filters. This paper reports an end-to-end fidelity and rate analysis for islands-based ZALM that includes: SPDC multipair emissions of all orders and partial-BSM losses in the ZALM QTX; loss in propagation from the ZALM QTX to Alice and Bob's
quantum receivers (QRXs); loss and mode mismatch in the mode converters employed at Alice and Bob's QRXs; and loss in the partial-BSM loading of Alice and Bob's emissive
quantum memories.
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Earth and Planetary Astrophysics
Scaled three-dimensional simulations of giant-planet accretion and disk clearing
Ignacio Mosqueira
We develop accelerated three-dimensional simulations of growing
planet pairs that draw on a finite gas reservoir. An annulus compression (Scaling A) shortens the predicted clearing time and shrinks the computational domain at equal grid resolution while preserving key physical parameters. Planetary seeds start with Hill radii equal to the disk scale height, retaining three-dimensional
accretion. We demonstrate the method in scaled PDS 70 and Solar-System configurations, assuming perfect Hill capture by growing
planets on circular orbits. We compare Scaling A at radius-compression factor \(\Gamma=1.75\) with the unscaled PDS system at matched resolution, through a 1% reduction of the interplanetary gas inventory. The scaled run is nearly an order of magnitude faster, with similar accreted mass and a comparable partition of gas between the
planets. For the Solar-System configuration at \(\Gamma=3\), the scaling forecasts a speedup of nearly two orders of magnitude at equal local resolution. The scaling is complementary to orbital advection. On eight CPU cores of a desktop computer, the scaled PDS 70 and Solar-System runs reduce the gas inventory between the orbiting
planets by roughly half in less than a day.
Accretion-driven orbital convergence narrows the shared feeding zone and, together with gas clearing, limits the planetary growth budget. In our scaled PDS 70 and Solar-System runs, the angular momentum carried by meridional inflow directly constrains delivery theory. These results establish a practical route to testing
accretion theory against simulations at matched scaled parameters, before applying it to unscaled planetary systems.
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Disordered Systems and Neural Networks
Quantum Localization in Geometric Complex Networks
Jan Lewenstein-Sanpera, Tobias Grass, M. Àngeles Serrano et al. (+1 more)
Quantum localization, the phenomenon by which wave
diffusion is halted, here understood as the superposition of propagating waves, can have many different origins, such as onsite random potentials in Anderson localization. However, some systems exhibit complex geometries and could potentially reproduce similar results without external potentials. In this work, we study how localization of single particle states is affected by the underlying
topology of a simple but highly predictive complex network model: the
geometric soft configuration model $\mathbb S^1$. By tuning the model's temperature and heterogeneity parameters, we are able to generate different structural patterns and focus on the transition from a small-world to a non-small-world regime. Our study suggests that small-world networks tend to have extended states, which spread the whole system's size, in contrast to non-small-world networks which tend to localize, showing how complex connectivity can play the role assigned to random energetic disorder.
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All authors Jan Lewenstein-Sanpera, Tobias Grass, M. Àngeles Serrano, Bruno Juliá-Díaz
Fluid Dynamics
Wave-driven geostrophic vortices in rotating turbulence
Vladimir Parfenyev and Sergey Vergeles
We perform direct numerical simulations of rotating
turbulence to investigate the mechanisms responsible for the maintenance of large-scale geostrophic
vortices. We confirm that the Reynolds stresses generated by inertial waves are consistent with the Reynolds-Averaged Navier-Stokes balance of the large-scale flow and demonstrate the predicted cyclone-anticyclone asymmetry, with cyclones exhibiting stronger azimuthal velocities and more compact cores. Wave-field analysis provides evidence that geostrophic
vortices selectively reflect and absorb inertial waves according to the sign of their angular momentum. Wave absorption occurs either through the formation of a critical layer ahead of the reflection point or through enhanced viscous dissipation associated with increasing local wavenumber. As rotation increases, fewer inertial waves undergo resonant absorption, reducing angular-momentum transfer to the
vortices and weakening the geostrophic flow. Consequently, the fraction of energy contained in geostrophic modes depends non-monotonically on the rotation rate, demonstrating that sufficiently rapid rotation can ultimately suppress, rather than enhance,
turbulence two-dimensionalization.
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Materials Science
Epitaxial Oxide Thin Films with High Entropy and Anomalous Crystallinity
Joseph Petruska, Christina M. Rost, Jon-Paul Maria et al. (+1 more)
Pulsed
laser deposition (PLD) expands the compositional and structural possibilities of high-
entropy oxide (HEO) thin films through far-from-
equilibrium growth and kinetic arrest of metastable configurations. This review connects growth kinetics and epitaxial constraints to the roles of individual cations in shaping the resulting films. We focus primarily on rock salt MgCoNiCuZnO and its derivatives, with selected fluorite, spinel, and perovskite examples illustrating broader applicability. In MgCoNiCuZnO, Co valence and Cu coordination illustrate how chemistry and growth conditions jointly enable
lattice tuning and coherent nanostructure formation, while aliovalent and size-misfit additions expand the accessible defect and compositional landscapes. These coupled degrees of freedom underpin anomalous crystallinity, the coexistence of extensive chemical disorder with exceptional crystalline quality and epitaxial order, including full coherence in selected systems, particularly rock salts grown on MgO. This combination opens opportunities to discover and engineer functional configurations in high-quality single-layer films and
heterostructures.
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All authors Joseph Petruska, Christina M. Rost, Jon-Paul Maria, Saeed S. I. Almishal
Fluid Dynamics
Capillary-gravity wave resistance of a translating, pulsating source
Haim Diamant and Elie Raphael
A disturbance in steady rectilinear translation along a capillary-
gravity interface radiates waves only above a minimum speed $c_{min}$, where it experiences a wave resistance; below this threshold it generates no waves, and the response is merely a localised deformation of the interface around the source, free of wave resistance. Modulating the source amplitude at a frequency $\Omega$ shifts the forcing to the sideband pair $kV\pm\Omega$, where $k$ is the wavenumber and $V$ is the translation speed, opening resonance conditions absent from the steady problem; radiation then sets in below the steady threshold $c_{min}$. Here we derive the mean wave resistance $\langle R\rangle$ of a line source in closed form, and show it to be strictly positive at every nonzero speed $V$: the drag-free below-threshold regime disappears for any $\Omega\neq 0$. Crossing the radiation transitions—where the group velocity matches the source speed—produces integrable resonant peaks in $\langle R\rangle$, whose exponents we derive, including at the cusp where two transition branches merge. Below threshold, where a steadily moving source feels no drag, $\langle R\rangle$ rises from zero as $\Omega^5$ (at fixed $V$). Throughout, surface tension is essential to $\langle R\rangle$: because it controls the short, dominant capillary-scale waves, discarding it misrepresents $\langle R\rangle$ over almost the entire speed-frequency plane.
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Chemical Physics
The RAS-CCSD model, with applications for open-shell molecules
Sarai Dery Folkestad
The restricted active space coupled cluster singles and doubles (RAS-CCSD) model, and its pilot implementation is detailed. The approach offers a simple, pragmatic way to formulate a coupled cluster theory for open-shell and multireference systems. For ground state energies, errors (compared to FCI) are shown to be similar to those of unrestricted (
spin-orbital) CCSD. For excited states, the errors of RAS-CCSD are generally larger, and adaptations to the methodology are needed to achieve an approach which is balanced for both ground and excited states. However, unlike unrestricted CCSD, the approach is
spin-adapted and can be used to add dynamical correlation to a multideterminantal reference state.
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Disordered Systems and Neural Networks
Eigenstate transitions and critical transport in 3D Aubry-André model
Pragna Das, Lev Vidmar and Miroslav Hopjan
We numerically study spectral and wave-function properties, as well as time
evolution, in finite-size commensurate approximations of the 3D Aubry-André model. We explicitly show, through scaling analysis, the existence of two critical points. One of the critical points is a localization-delocalization transition in real-space, similar to the critical point in the 3D Anderson model. The other is a localization-delocalization transition in a dual momentum space, which does not have any analog in the 3D Anderson model. We estimate their values from spectral measures, such as the gap ratio and the spectral form factor, as well as from wave-function measures, such as the inverse participation ratio and the participation
entropy. Additionally, we demonstrate that both critical points exhibit hallmarks of critical points between
quantum ergodicity and localization. First, the eigenstates and the eigenspectrum at the critical point fulfill the mutual universal relation between the eigenspectrum compressibility $\chi$ and the eigenstate fractal dimension $d^{(1)}$ [S. Jiricek et al., Proc. Nat. Acad. Sci. 123, e2518027123 (2026)]. Second, the dynamics of the wave packet at the critical point is governed by the critical dynamical exponent $z$, characterized by the spectral fractal dimension and the dimensionality of the
lattice [M. Hopjan and L. Vidmar, Phys. Rev. Lett. 135, 060401 (2025)]. Thus, similarly to the 3D Anderson model, the critical dynamical exponent is sub-diffusive with the value of $z=3$.
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High Energy Physics (Phenomenology)
Dalitz plot binning optimization for the model-independent measurement of the CKM angle $\beta$ with $B^0 \to D \pi^+ \pi^-$, $D \to K_S^0 \pi^+ \pi^-$ decays
Anfeng Li, Wenbin Qian, Boan Shi et al. (+2 more)
A model-independent measurement of the CKM angle $\beta$ can be performed using a time-dependent analysis of $B^0 \to D \pi^+ \pi^-$, $D \to K_S^0 \pi^+ \pi^-$ decays, where the Dalitz plots of both the $B$ and $D$ decays are divided into bins. The choice of binning scheme for the $B^0 \to D \pi^+ \pi^-$ Dalitz plot directly impacts the statistical sensitivity to $\beta$. This paper presents an optimization of this binning using a Fisher information-based quality factor $Q^2$ and simulated annealing. The optimized binning improves the sensitivity to $\beta$ by approximately $10\%$ relative to the equal-phase-difference baseline, as validated by toy Monte Carlo studies without experimental effects. The robustness of this improvement against decay time acceptance, Dalitz plot efficiency, Dalitz plot resolution, and background contributions is also assessed.
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All authors Anfeng Li, Wenbin Qian, Boan Shi, Ao Xu, Liming Zhang
High Energy Physics (Theory)
Area metric gravity à la Plebanski: connection, curvature and dynamics
Bianca Dittrich
Area metrics arise as effective description at intermediate scales in a number of approaches to
quantum gravity, including string theory, holography and loop
quantum gravity. Recently, it has been shown that area metric actions can be derived from the modified Plebanski framework on the linearized level. Surprisingly these actions avoid extra poles in the propagator for the effective length dynamics, and hence constitute interesting deformations of linearized Einstein
gravity. To be able to study whether this property persist for the full theory, we construct here non-linear area metric dynamics from modified Plebanski actions. We provide the
geometric tools for area metrics that do not rely on perturbation theory and allow a systematic construction and study of general non-linear area metric actions: an
algorithm that extracts a length metric from an area metric and a connection on two-forms that is uniquely determined by the area metric, together with its
curvature and
curvature invariants. We derive area metric actions from modified Plebanski actions in first and second order versions. We also find that area metric actions can be reformulated as Poincare gauge theories. We determine the effective length metric action, which on a flat background describes a graviton and a massive
spin-two field with parity-violating couplings set by the Barbero–Immirzi parameter. Additionally we discuss cosmological backgrounds and the role of the matter coupling, which together open the way to cosmological applications.
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Soft Condensed Matter
Emergence of Active Foams in a Minimal Cognitive Flocking Model
Aryan Dwivedi, Diganta Bhaskar and Anil Kumar Dasanna
We investigate a minimal visual perception-driven model of self-propelled particles that interact through purely position-based cohesive steering within a finite
vision cone, in the absence of velocity
alignment and physical volume exclusion. Building on a previously proposed minimal cognitive model, we extend the interaction range from the previously studied short-range and distance-independent limits to an intermediate regime, enabling a systematic investigation of how a finite
vision range influences collective behavior. We find that this regime exhibits a rich state diagram that combines characteristics of both limiting cases while giving rise to qualitatively new collective states. Besides the gas, nematic-band, and polar file states, we uncover the emergence of active foams – system-spanning fractal-like networks sustained by dynamically evolving particle streams. These structures arise solely from non-reciprocal
vision-based interactions and are absent in both the short and long
vision-range limits. For larger
vision angles, the system self-organizes into a variety of aggregate morphologies, including condensates, rings, and multi-twist filaments, revealing a strong interplay between interaction range and anisotropic perception in shaping collective organization.
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Optics
Photon-efficient readout of optical cavity arrays via spatial heterodyne
Bridger McGimpsey and Matt Jaffe
Optical cavity arrays are an emerging tool for efficiently interfacing optical
photons to
quantum emitters for applications such as
quantum computing. In this work, we demonstrate a metrology technique for such cavity arrays by interfering cavity array outputs against a tilted reference beam on a camera, constituting a spatial heterodyne. Both the amplitude and phase of each cavity's transmitted field can be extracted from the resulting images. Enabled by the improved scaling of heterodyne detection over intensity detection in the presence of technical noise, we demonstrate signal-to-noise ratio greater than one down to the single detected
photon level, even in the presence of hundreds of noise equivalent
photons. This readout technique holds promise for fast, non-destructive imaging of atomic
qubits in cavity arrays by requiring fewer scattered
photons while allowing the use of fast cameras with higher electronic readout noise.
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Applied Physics
Acoustic Scattered Field Calculation for a Moving Source Using Time-Dependent Physical Optics
Asaf Kor, Gal Ben Yelid, Amir Boag et al. (+1 more)
We present a time-dependent physical optics (TDPO) formulation for computing the acoustic scattered field of a stationary object in response to a moving source in three-dimensional space. Due to the motion of the source, which may be fast, the conventional frequency-domain PO method is not employed. Instead, a time-domain variant that explicitly accounts for the motion is formulated. The study focuses on the near-field regime, where source motion induces a complex wave field beyond a simple Doppler effect. The proposed
algorithm accommodates arbitrary source trajectories and arbitrary signal bandwidth, as well as high source velocities relative to the speed of sound. Near and beyond the shadow boundary, where PO is least accurate, the formulation is supplemented by a Fock correction of the surface field, extended here to a moving source with a harmonic signal. The method matches or exceeds the accuracy of finite element simulations at a computational cost lower by orders of magnitude.
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All authors Asaf Kor, Gal Ben Yelid, Amir Boag, Lea Beilkin-Sirota
Instrumentation and Methods for Astrophysics
The Long-Term Radial Velocity Stability of the COS G130M/1291 Mode
John Debes, David M. French, Leonardo A. Dos Santos et al. (+3 more)
We investigate the long-term radial velocity (RV) stability of one of the Far-UV (FUV) modes on the
Cosmic Origins Spectrograph (COS). We do so by using a standard white dwarf, WD~0308-565, that has been observed over a large fraction of COS's operational lifetime of 17 years. We demonstrate that for modest signal-to-noise COS can return an RV stability of $<$3 km s$^{-1}$ over a baseline of 15 years. For higher SNR and a smaller number of epochs, we obtain $\sigma_{\mathrm V}=600$ m s$^{-1}$. We also show that the absolute radial velocity accuracy for this target is consistent with results from ground-based optical spectroscopy. We discuss some observational strategies and astrophysical objects that may be well suited to pushing to the very RV limit of the instrument. Utilizing COS for precision RV work opens a new scientific avenue for space-based UV astronomy as COS approaches 20 years of operations and hints at what may be possible with the stability of a high-resolution UV spectrograph on future missions such as the Habitable Worlds Observatory.
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All authors John Debes, David M. French, Leonardo A. Dos Santos, Travis Fischer, Svea Hernandez, Ravi Sankrit
Fluid Dynamics
Nanofluid transport in Taylor bubble flows
Fahad Al-Gburi, Faysal Khaleel, Yulong Ding et al. (+1 more)
Taylor bubble flows with nanoparticle suspensions are regularly encountered in non-isothermal chemical synthesis and microfluidics. Despite this, a complete mechanistic insight into the coupled thermal and hydrodynamic interactions remains unresolved. Here, a Eulerian-Lagrangian framework has been developed to address this, capturing two-way momentum, energy exchange, and nanoparticle interactions under non-isothermal conditions. We find that Brownian motion acts in two opposing ways, enhancing local particle-fluid energy exchange yet driving a thermophoretic drift away from the heated wall that strengthens as particle diameter is reduced below 100 nm. At particle volume fractions of $\phi \sim 10^{-2}$, Taylor flow departs from the Nusselt scaling with dimensionless slug length, $\tilde{L}_s$, observed for particle-free flows. This coincides with alterations to bubble
topology that co-benefit nanoparticle momentum and energy exchange with the carrier fluid. Examining both Poiseuille and Taylor flow problems, we observe contrasting, often opposing dimensionless heat transport behaviours, questioning the suitability of traditionally accepted mixture approaches. This work reveals that, in the visco-inertial regime ($Re > 500$), it is the interplay of hydrodynamic, Brownian, and interfacial forces, combined with the Taylor bubble and slug flow
topology, which determine positive or negative $Nu$ outcomes. Interestingly, short-range particle forces at the
liquid-gas interface work synergistically with the convective motion in the slug to alter local particle concentration and energy exchanges within downstream thin film and near-wall regions. The intensity of this convective flow was found to impact both slug and film transport phenomena, improving the redistribution of nanoparticles when $\tilde{L}_s \leq 1.6$ and with increasing $Re$.
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All authors Fahad Al-Gburi, Faysal Khaleel, Yulong Ding, Jason Stafford
Instrumentation and Methods for Astrophysics
Occultation polarimetry as a probe of unresolved polarization
A. G. Tevzadze
Context: Low polarization in an unresolved source may reflect weak local polarization or spatial cancellation between strongly polarized regions. An occultation can break this spatial degeneracy by differentially sampling the source as the occulting boundary moves. Aims: We develop a general theoretical framework for occultation polarimetry and determine what information can be inferred directly from unresolved full Stokes light curves, without reconstructing a polarization image or prescribing a source model. Methods: For a stationary, spatially incoherent source undergoing monotonic occultation, we relate Stokes variations to the polarization sampled by an arbitrarily curved occulting boundary and derive an exact variance decomposition of the normalized Stokes vector. Results: The polarization deficit decomposes exactly into three non-negative contributions: local polarization deficit, mixing within limb samples, and mixing between their mean polarization states. The last is directly measurable and provides a sharp, model-independent lower bound on total spatial mixing. The associated covariance tensor further characterizes the direction and correlations of the resolved polarization variations, including those between linear and circular polarization. Finite sampling preserves the bound, which can be strengthened through complementary occultation trajectories. Conclusions: Occultation polarimetry provides a powerful observational technique for extracting quantitative, model independent constraints on spatial polarization mixing directly from unresolved Stokes light curves. It offers a means to reveal both the extent and the form of polarization structure otherwise inaccessible at the available angular resolution.
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