Soft Condensed Matter
Unmasking the internal structure of casein micelles through enzymatic hydrolysis: A SAXS study
Julien Bauland, Ghazi Ben Messaoud, François Boué et al. (+4 more)
Casein micelles, one of the most studied natural association colloids, are supramolecular assemblies of caseins and colloidal calcium phosphate that constitute the fundamental building blocks of dairy
matrices. Despite extensive investigation, the internal structure of casein micelles remains debated. While $\kappa$-casein is known to ensure colloidal stability of casein micelle suspension, the spatial organization of casein fractions and salts is still unresolved, and several structural models coexist. Small-angle scattering is a method of choice to probe biological colloids in situ, yet interpretation of scattering data remains challenging due to the hierarchical nature of casein micelles. Here we address this issue by probing micelle structure during enzymatic gelation induced by chymosin, which cleaves $\kappa$-casein and triggers aggregation. Using time-resolved SAXS, we probe structural changes throughout the sol-gel transition over length scales from 3 nm to 3 $\mu$m. First, we show that enzyme-driven aggregation, counterintuitively, reveals information about the internal organization of casein micelles: the reduction of specific surface area during gelation unmasks a high-q structural peak previously observed under contrast-matching conditions. Second, we report that $\kappa$-casein cleavage leads to a gradual disappearance of the structural feature at intermediate scales. Analysis of the disappearance kinetics and comparison to structural models reveal that $\kappa$-casein cleavage induces a progressive relaxation of the colloidal porous substructure, providing direct evidence for its contribution to micellar organization. More broadly, these results demonstrate that the gelation process provides unique access to the internal structure of biological colloids and offers new perspectives for interpreting scattering data in complex soft-matter systems.
Read the full abstract ▾
All authors Julien Bauland, Ghazi Ben Messaoud, François Boué, Pascaline Hamon, Florence Rousseau, Thomas Gibaud, Thomas Croguennec
Optics
Oscillator-driven broadband femtosecond transient microspectroscopy with supercontinuum probes generated in a photonic crystal fiber
Rikuto Fukuda, Kyosuke Kishihata, Ryo Man-nami et al. (+4 more)
We present an oscillator-driven femtosecond transient microspectroscopy system based on supercontinuum generation in a photonic
crystal fiber (PCF). The system operates at 80 MHz without pulse amplification, enabling high-sensitivity measurements with a detection sensitivity better than $10^{-4}$ while using low pulse energies suitable for microspectroscopy. Optimization of the PCF length ($\leq 50$ mm) suppresses dispersion-induced chirp, achieving nearly uniform temporal resolution below 100 fs across 450-900 nm. The high-repetition-rate operation allows rapid spectral acquisition and efficient noise reduction. The developed system provides micrometer-scale spatial resolution and supports both reflection and transmission configurations. Ultrafast carrier dynamics in multilayer and monolayer MoS$_2$ are successfully resolved, including spatially dependent relaxation within a single monolayer flake. These results demonstrate a versatile platform for probing local ultrafast dynamics in low-dimensional materials.
Read the full abstract ▾
All authors Rikuto Fukuda, Kyosuke Kishihata, Ryo Man-nami, Hiroaki Atsumi, Borja Cirera, DaeGwi Kim, Masahiro Shibuta
General Relativity and Quantum Cosmology
Dynamics of Charged Radiating Collapse with Shear and Anisotropy
A. Khalid, Muhammad Bilal Riaz, S. A. Mardan et al. (+1 more)
We investigate a charged anisotropic radiating
stellar configuration undergoing gravitational collapse in the presence of shear and heat flux within the Einstein Maxwell framework. The interior spacetime is described by a time dependent spherically symmetric geometry and is matched to an exterior charged Vaidya spacetime. The electromagnetic field is incorporated explicitly through Maxwell equations, allowing the electric charge to contribute to the matter variables, mass function, and boundary
evolution. The charged junction condition is reduced to a Riccati type differential equation with suitable transformations and exact solution is obtained. The physical properties of the resulting shearing solution are examined through the energy density, radial and tangential pressures, pressure anisotropy, heat flux, electric charge, energy conditions, sound speeds, Herrera cracking criterion, and complexity factor. The energy density and radial pressure remain positive and decrease towards the
stellar surface, whereas the tangential pressure remains negative, confirming the anisotropic character of the configuration. Heat transport and electromagnetic effects are strongest in the inner
stellar region. The energy and causality conditions are satisfied. The cracking function indicates potential stability against cracking. The complexity factor remains positive, with electric charge providing an additional contribution alongside pressure anisotropy, density inhomogeneity, and dissipative heat flux. These results provide a comprehensive picture of the physical behavior and internal structure of the charged shearing radiative collapse model.
Read the full abstract ▾
All authors A. Khalid, Muhammad Bilal Riaz, S. A. Mardan, Mustafa Inc
Materials Science
A low-temperature setup for lock-in technique based dynamic magnetoelectric coupling measurements
Balwant Singh Chauhan, Priyanka Sharma, Rie Y. Umetsu et al. (+1 more)
Magnetoelectric (ME) phenomena in emerging material classes, such as two-dimensional van der Waals (vdW) magnets and Single-Molecule Magnets (SMMs), hold immense promise for next-generation cryogenic
memory and
quantum technologies. However, ME coupling in these systems predominantly manifests at low temperatures, making a sensitive, cryo-compatible ME characterization techniques critical. To address this requirement, we report the design, validation, and performance of a custom closed-cycle refrigerator-based setup for dynamic lock-in ME coupling measurements across 20-300 K under dc
magnetic fields up to 7.5 kOe. Key design considerations for mitigating parasitic inductive background signals are also presented. The setup was validated on a CoFe2O4-BaTiO3 (CFO-BTO) particulate composite, reproducing the characteristic room-temperature butterfly ME loop with a maximum ME coefficient value of 0.23 mV/cm-Oe at ~ 3 kOe. Temperature-dependent measurements resolved ME anomalies at ~ 200 K and 280 K, coinciding with the rhombohedral-orthorhombic and orthorhombic-tetragonal structural transitions of BaTiO3, and were corroborated by simultaneous dielectric measurements on the same sample without cryostat reconfiguration. The instrument enables reliable ME and dielectric characterization down to 20 K, making it well suited for probing weak magnetoelectric coupling and phase transitions in multiferroic composites and
quantum materials.
Read the full abstract ▾
All authors Balwant Singh Chauhan, Priyanka Sharma, Rie Y. Umetsu, Ratnamala Chatterjee
High Energy Physics (Theory)
Hilbert space relation from dS to AdS through Reflection Positivity
Yu-ki Suzuki
De Sitter unitarity and reflection positivity are logically independent. We study their relation for a free scalar field on a fixed de Sitter background, restricting
attention to the one-particle sector. Motivated by Witten's de Sitter pairing and the radial adjoint of Bousso, Maloney and Strominger, we compose the invariant
Hilbert product with equatorial reflection. In the standard principal-series realization, this form vanishes identically and its Osterwalder-Schrader quotient contains no states. For the complementary series, the reflected product becomes a nonzero reflected kernel on the unit ball. A result of Neeb and Ólafsson shows that this kernel is positive semidefinite precisely when the lower weight satisfies the scalar conformal unitarity bound. The resulting
Hilbert space with the reflected inner product furnishes a positive-energy representation of AdS isometries according to Neeb and Ólafsson. We identify that the range coincides with the Klebanov-Witten alternative-quantization window from physics point of view. This correspondence suggests a novel relation from the representation viewpoint between AdS and dS without the conventional analytic continuation of radius.
Read the full abstract ▾
Mathematical Physics · Cross-listed from math.CO
Enumeration of plane hypermaps with a mixed boundary I
Jérémie Bouttier, Bertrand Eynard and Thomas Lejeune
Plane hypermaps are plane maps endowed with a proper coloration of their inner faces in black or white. We consider the problem of enumerating plane hypermaps with prescribed face degrees and a $k$-alternating boundary condition: by this we mean the colors of inner faces incident to the outer face alternates at most $2k$ times when turning around the hypermap. The present paper deals with the cases $k=1,2$, the general case being left to the forthcoming part II. Our approach relies on the so-called slice decomposition and uses crucially the notion of accessibility, which exploits the canonical orientation of hypermaps and the marking variable $t$ associated with vertices, to enumerate pointed hypermaps by decomposing them according to the set of all vertices that can access to the marked vertex. This process enables us to express the generating functions of hypermaps with mixed boundaries in terms of the generating functions of hypermap slices and to recover, in a purely combinatorial way, some formulas previously obtained through algebraic methods.
Read the full abstract ▾
Materials Science
Tuning of Photoexcited Electron Dynamics at Monolayer h-BN/Metal Interfaces by Corrugation
Masahiro Shibuta, Maximilian Schaal, Marco Gruenewald et al. (+4 more)
Atomic-scale corrugation in two-dimensional materials can modify interfacial electronic coupling, yet its influence on ultrafast carrier relaxation remains poorly established. Here, we compare image potential states (IPS) at monolayer h-BN/Ir(111) and h-BN/Pt(111) interfaces using structural characterization and time-resolved two-
photon photoemission spectroscopy. Consistent with literature, h-BN is strongly corrugated on Ir(111) but comparatively flat on Pt(111). The first (n = 1) and second (n = 2) IPS appears at similar energies on both substrates, whereas their relaxation dynamics differ markedly. On h-BN/Ir(111), the IPS decay is response-limited (<20 fs), while h-BN/Pt(111) exhibits lifetimes of 56 fs (n = 1) and 75 fs (n = 2). The lifetime contrast is most consistently explained by corrugation-enhanced overlap of the IPS wavefunction with the metal substrate, which accelerates electron decay. These results indicate that atomic-scale corrugation is an effective physical parameter for tuning ultrafast electron dynamics at two-dimensional material and metal interfaces.
Read the full abstract ▾
All authors Masahiro Shibuta, Maximilian Schaal, Marco Gruenewald, Jonas Brandhoff, Felix Otto, Roman Forker, Torsten Fritz
Quantum Physics
Entangling two qudits of arbitrary dimension through light-atomic Faraday interaction
R. Surmay, V.A. Leonov and E.A. Vashukevich
The paper investigates entangling operations acting on two qudits of arbitrary dimension, with one encoded in the states of a spatially multimode optical field, the other in those of atomic collective
spin coherence, both carrying orbital angular momentum (OAM). We demonstrate the generation of a wide range of entangling operations within a protocol consisting of two Faraday interactions and a rotation of atomic and light quadratures between them. All generated gates can be represented as rational powers of the d-dimensional gate $SWAP^{\alpha}_d$. The probabilities of two-qudit transformations are calculated for various dimensions of the logical space and for different entangling powers of the logical gates.
Read the full abstract ▾
Quantum Physics
Imaginary time evolution of a quantum system through analytic continuation from real-time quantum simulation
Peng Guo, Anto Shibu, Joshua Lin et al. (+1 more)
Though
quantum computing naturally offers an advantage for simulations of real-time
quantum systems, implementing Imaginary-Time
Evolution (ITE) is comparatively more difficult. Nevertheless,
quantum implementations of ITE are useful both in cases where classical implementations have associated sign problems, and also as an exact method of preparing eigenstates on
quantum computers. In this work we present an
algorithm to obtain ITE of a generic
quantum Hamiltonian by performing analytic continuation of measured real-time correlation functions. We present simulations and demonstrations on IBM
quantum hardware of 1D Fokker-Planck equations for classical
diffusion process and imaginary-time
evolution of integrated correlation functions in 1D
quantum mechanical scattering as examples to demonstrate the effectiveness of the method.
Read the full abstract ▾
All authors Peng Guo, Anto Shibu, Joshua Lin, Yong Zhao
High Energy Physics (Theory)
A Note on a High-Energy Limit of Gravitational Perturbation Theory
Poul H. Damgaard and Ludovic Plante
The post-Minkowskian expansion of general relativity expands the metric in Newton's constant G around flat space-time, but much effort currently focuses on ways to extend its range of applicability by summing the perturbative series to all orders. A regime of particular interest is a specific high-energy limit where a formula derived recently provides the momentum kick of binary scattering problem to all orders, and even suggests an approach towards strong coupling. We show that this is an asymptotic expansion. Although the series diverges we give evidence that it is Borel summable, and the full function in integral form is finite. As a by-product we determine the transcendentality properties of the coefficients in the expanded expression.
Read the full abstract ▾
Computational Physics
Diagonalization of the Landau Hamiltonian with a Periodic Potential via a Galerkin Projection Method and Applications to Topological Band Properties
Rafael Antonio Lainez Reyes, Benjamin Stamm and Hans Peter Büchler
In this paper, we study the numerical computation of eigenfunctions of the Landau
Hamiltonian with a periodic potential. We propose a spectral method using the eigenfunctions of the Landau operator that allows us to numerically compute the band structure for potentials of different strengths, including the well-studied weak and strong potentials, and additionally systems in the intermediate regime. We then apply the method to simulations across the full range of coupling constants from weak to strong coupling and present an analysis of the band structure as a function of the potential strength.
Read the full abstract ▾
General Relativity and Quantum Cosmology
Universal Relations for Neutron Stars from Asymptotic Analysis
Syo Kamata, Josuke Minamiguchi and Shuhei Minato
Dimensionless observables of
neutron stars, such as the moment of inertia, the
tidal deformability, the
spin-induced quadrupole moment, and the compactness, satisfy the I–Love–Q and Love–$C$ universal relations to percent-level accuracy over a wide range of equations of state. We investigate analytically the origin of this insensitivity in the
stellar structure equations. We derive asymptotic expansions of these relations directly from the differential equations and boundary conditions for slowly rotating, tidally deformed
stars described by a general piecewise-polytropic equation of state. Although the differential equations allow several forms of the asymptotic expansion, we find that only one class is consistent with the observed universality, and we use this class to analyze the universal relations. Because the observables are determined at the
stellar surface, information about the deep-interior equation of state can enter them only through the parameters that survive in the asymptotic expansion at the surface. We find that the universal relations depend only on three parameters: two integration constants and one polytrope index of the outermost segment. By determining how these parameters deform the relations, we show that, throughout the region of parameter space occupied by realistic equations of state, the resulting deviations remain at the percent level, consistent with the observed accuracy of the universal relations. Within the same formalism, we classify violations of universality according to the additional degrees of freedom or input data responsible for them. Since the construction relies only on the underlying differential equations and boundary conditions, the same procedure can be applied to other systems once the corresponding equations and boundary conditions are specified.
Read the full abstract ▾
Optics
Full frame denoising for pyramid wavefront sensors
Noah Schwartz, Samuel Pinilla, Charlotte Z. Bond et al. (+3 more)
Adaptive optics systems operating under low-flux conditions face significant challenges, as
photon and detector noise in particular degrade wavefront measurements and ultimately limit correction performance. While pyramid wavefront sensors (PyWFSs) offer greater sensitivity than conventional wavefront sensors such as the Shack-Hartmann sensor in many operating regimes, obtaining accurate wavefront estimates under
photon-starved conditions remains a key challenge. We present a full-frame image denoising strategy for the PyWFS that exploits the nonlocal self-similarity of wavefront sensor image patches through FFT-accelerated patch grouping and global collaborative 3D wavelet filtering, applied directly to the raw PyWFS intensity frame prior to slope computation. Specifically, the method suppresses noise while preserving structural features required for accurate wavefront reconstruction. The approach is evaluated using end-to-end simulations of a VLT-scale SCAO system. The results show improved performance in low signal-to-noise regimes, with typical Strehl ratio gains of up to 12% and an increase in limiting magnitude of approximately 0.5 in median seeing conditions. Modal analysis indicates reduced variance across most controlled modes. The improved PSF quality enables a reduction in the FWHM and an enhanced contrast. These results demonstrate that image-domain denoising can improve the robustness of PyWFS-based AO systems and extend their operational range toward fainter guide
stars.
Read the full abstract ▾
All authors Noah Schwartz, Samuel Pinilla, Charlotte Z. Bond, Ben Buky, Gianfelice Cinque, Robert Rambo
Materials Science
Building atomistic models of heterointerfaces with optimal transport
Yuxuan Tang and Keith T. Butler
Heterogeneous interfaces underpin technologies from microelectronics to energy conversion and storage, but their configurational complexity precludes exhaustive first-principles screening of interface registries. Although data-driven approaches can alleviate this burden, they remain limited by sparse interface
datasets. Here, we introduce an energy-independent workflow that represents coherent interfaces as attributed graphs, quantifies their similarity to parent bulk environments using the fused Gromov-Wasserstein (FGW) distance, and couples this metric with
Bayesian optimization over the in-plane registry space. We assess the approach for KI/NaCl, GaP/GaAs and GaN/$\mathrm{Al_{2}O_{3}}$ interfaces spanning ionic, covalent and mixed-bonding regimes, using hierarchical validation with MACE and density functional theory (DFT). Comparison with single-point energy landscapes shows that the FGW distance captures registry-dependent periodicity, while interfaces exhibit deviations between structural and energetic extrema, reflecting additional chemistry-specific contributions. Furthermore, FGW distances show an overall association with relaxed energies. Under limited screening budgets, FGW-guided registry selection consistently outperforms random search and is more robust across interface systems than selection guided by pretrained MACE energies. The workflow converts the qualitative notion of bulk-like continuity into a quantitative prescreening criterion, enabling efficient registry exploration and providing physically informed candidate structures for materials discovery workflows.
Read the full abstract ▾
Biological Physics
SoilWaterNow: Soil water nowcasting for mapping plant available water (PAW) across paddocks for improved on-farm decision-making
Yi Yu, Mikaela J. Tilse, Patrick Filippi et al. (+1 more)
Timely, paddock-scale estimates of plant-available water (PAW) can support crop management in water-limited grain systems. We present the Sydney Soil Water-Energy Balance (SWEB) model, a scalable, physically consistent modelling framework that integrates satellite and
climate data with soil properties to estimate crop evapotranspiration and root-zone soil moisture (RZSM) at daily, 30 m resolution. SWEB was validated nationally against different SM monitoring networks across Australia, which demonstrated robust performance across diverse grain-growing environments (correlation coefficients generally ranged from 0.70 to 0.85 for most regions). In future applications, mid-season PAW nowcasts could be combined with water-use-efficiency approaches to estimate water-limited yield potential and inform responsive management decisions, such as nitrogen fertiliser top-up recommendations.
Read the full abstract ▾
All authors Yi Yu, Mikaela J. Tilse, Patrick Filippi, Thomas F. A. Bishop
Solar and Stellar Astrophysics
SN 2021pfs: A Type Ia Supernova Likely Affected by Progenitor Metallicity, as Revealed by Comparison with Its Twin Counterpart
Abdusamatjan Iskandar, Xiaofeng Wang, Ali Esamdin et al. (+16 more)
We present extensive photometric and spectroscopic observations of the normal type Ia
supernovae (SNe Ia) 2021pfs, which occurred in the Seyfert 2
galaxy NGC 5427 at a
redshift 0.009. SN 2021pfs reached an absolute B-band peak magnitude of $M_{\rm max}(B)=$-19.28 $\pm$ 0.40 mag. The mag and a post-peak decline rate of $\Delta m_{15}(B)=$1.13 $\pm$ 0.06 mag. The observed properties of this nearby SN Ia closely resemble those of SN 2011fe, including the main optical spectroscopic features and photometric
evolution. Despite their similar decline rates, SN 2021pfs rose more rapidly in the $U$ band but more slowly in the $r$ and $i$ bands compared to SN 2011fe in very early phases. This photometric difference, particularly at short wavelengths, can introduce a systematic uncertainty of up to $\sim$12% in distance estimates. Analysis of the host
galaxy's local and global environment shows an environment consistent with producing a higher-
metallicity progenitor for SN 2021pfs than that of SN 2011fe.This higher progenitor
metallicity may explain the observed photometric discrepancy and the resulting distance between SN 2021pfs and SN 2011fe, though a larger sample of such "twin" SNe Ia is needed to confirm this trend and assess its impact on cosmological measurements.
Read the full abstract ▾
All authors Abdusamatjan Iskandar, Xiaofeng Wang, Ali Esamdin, Wenxiong Li, Xiangyun Zeng, Ruifeng Huang, Hu Maokai, Guoliang Lu, D. Andrew Howell, Curtis McCully, Samuel Wyatt, Daichi Hiramatsu, Estefania Padilla Gonzalez, Craig Pellegrino, Megan Newsome, Lluis Galbany, David J. Sand, Nathan Smith, Huei Sears
High Energy Astrophysical Phenomena
J0011+3443: a GPS compact symmetric object, gravitational lens, or dual AGN?
Efthalia Traianou, Tingting Liu, Roman Gold et al. (+1 more)
We present new multi-frequency VLBA observations of J0011+3443 (TXS 0008+344, z = 0.89) at 2.3, 4.9, 8.5, and, for the first time, 23.6 GHz. The source consists of two compact components A and B at a projected separation of 314 +/- 2 pc, plus a third feature C detected at 23.6 GHz at 0.6 mas from A. Archival low-resolution
radio measurements confirm an integrated gigahertz-peaked spectrum, with an observed-frame peak frequency of 0.73 +/- 0.08 GHz and a peak flux density of 879 +/- 125 mJy. Comparison with nearly frequency-matched low-resolution measurements shows that the VLBA recovers 0.85 +/- 0.11 of the 4.85 GHz flux density and 0.50 +/- 0.06 of the 8.46 GHz flux density. The lower recovered fraction at 8.5 GHz suggests that low-surface-brightness emission is resolved out or falls below the VLBA surface-brightness sensitivity. We therefore interpret the VLBA component spectra as spectra of the compact recovered emission only. The 23.6 GHz morphology, the absence of a detected flat-spectrum core, the similar compact spectra of A and B, and the steep integrated GHz spectrum favor an interpretation of J0011+3443 as a GPS-class compact symmetric object, possibly in a short-lived or relic phase, although a dual-AGN origin cannot be excluded without multi-epoch astrometry.
Read the full abstract ▾
All authors Efthalia Traianou, Tingting Liu, Roman Gold, Richard Mushotzky
Plasma Physics
Effect of ion temperature on lunar photoelectron sheath
Trinesh Sana and Sanjay K. Mishra
Observations suggest that the
solar wind ions impinging on the lunar surface possess a finite temperature. The effect of ion temperature on the
plasma sheath over the lunar surface is investigated in this paper. To account for thermal effects, a thermal pressure term has been added to the ion-flow force equation. Quantitative estimation of sheath characteristics has been performed by solving the Poisson equation, accounting for photoelectrons,
solar wind electrons, and warm ions. Notably, the presence of warm ions within the sheath, i) changes the potential, field, sheath population density structures, ii) changes the sheath thickness, iii) reduces the photoelectron trapping, and iv) reduces
solar wind electron reflection, compared to cold ions. The effect is more prominent at high lunar latitudes, which in turn may significantly modulate the
dust dynamics.
Read the full abstract ▾
Instrumentation and Detectors
An Overview of Potential Medical Applications of Microwave Kinetic Inductance Detectors
Cáthal McAleer, Gary Donegan, Colm Bracken et al. (+4 more)
Microwave kinetic inductance detectors (MKIDs) have proven to be a versatile detector technology and are very promising for several applications in medical imaging. Deep imaging into human tissues often requires detectors with low background noise, high detection efficiency, broad wavelength sensitivity or single-pixel energy resolution. MKIDs offer a unique combination of valuable features for medical imaging but have so far not been discussed much for modern medical instrumentation. This represents an exciting opportunity to investigate the potentially powerful advantages MKIDs could offer for clinical studies in several areas. The most promising fields for MKIDs in medical imaging include fluorescence microscopy, near-infrared spectroscopy, energy-resolved medical X-ray imaging and synchrotron X-ray microscopy. We present the respective advantages MKIDs offer for these fields and compare them to current detector state-of-the-art.
Read the full abstract ▾
All authors Cáthal McAleer, Gary Donegan, Colm Bracken, Oisín Creaner, Mario De Lucia, Tom Ray, Gerhard Ulbricht
Quantum Physics
Disassembling qLDPC codes for depth-optimal parity-check circuits
Minh T. P. Nguyen, Maximilian Rimbach-Russ and Stefano Bosco
Quantum low-density parity-check (qLDPC) codes offer a promising route to scalable fault-tolerant
quantum computing, but their practical implementation requires efficient
circuits for syndrome extraction. Many qLDPC families are assembled from a small set of components through explicit operations that imprint edge
symmetries on their Tanner graphs. We show that disassembling the code by quotienting its
symmetries one at a time, reduces parity-check
circuit design to a much smaller problem acting only on the underlying components. Solutions to the reduced problem can then be lifted to the full code, yielding
circuit constructions that apply to entire families of codes built from the same components. For lifted-product codes, our approach provides an optimal analytical construction for parity-check
circuits achieving the lower bound on CNOT depth. We obtain analogous constructions for balanced-product codes and
quantum–classical homological product codes. For
quantum Tanner codes, the reduced problem is small enough to solve numerically, reaching the CNOT-depth lower bound for nearly all instance tested, including codes with up to 576 data
qubits.
Read the full abstract ▾
High Energy Physics (Experiment)
Distilling Normalizing Flows for Real-Time Anomaly Detection at the LHC
Tara P. A. Tahseen, Noah Clarke Hall, Nikolaos Konstantinidis et al. (+1 more)
Normalizing flows are principled anomaly detectors, selecting anomalies using a probabilistic per-event likelihood. Extreme latency and resource constraints have prevented the deployment of flow likelihoods within the hardware triggers at the Large
Hadron Collider. We bypass these limitations by distilling the likelihood from a large normalizing flow into lightweight student
estimators suitable for deployment on a field-programmable gate array. Our use of a conditional normalizing flow enables precise likelihood estimation in the presence of missing input features. Both decision tree and neural network students are considered, the latter optimized under advanced quantization techniques. By simultaneously improving likelihood quality and lowering inference cost, we demonstrate both state-of-the-art physics performance and latency compared with existing flow-based approaches.
Read the full abstract ▾
All authors Tara P. A. Tahseen, Noah Clarke Hall, Nikolaos Konstantinidis, Paula Martínez Suárez
Mesoscale and Nanoscale Physics
Search for Majorana Bound States in Short Chains of Proxmitised Quantum Dots
Bogdan R. Bułka and Karol I. Wysokiński
Majorana zero modes (MZM) appearing at the ends of artificially created one-dimensional p-wave
superconductors have been intensively studied recently both theoretically and experimentally. Among possible platforms, proximitised semiconducting wires, and short chains of
quantum dots with a
superconductor in between were investigated. Here, we propose a different platform consisting of a chain of
quantum dots (QDs) sandwiched between an s-wave
superconductor and a strong
spin-orbit
semiconductor, subject to a Zeeman
magnetic field. Neglecting
spin-conserving hopping processes between QDs and local on-dot superconducting correlations induced by the superconducting proximity effect, reduces the
Hamiltonian to the sum of two equivalent
Hamiltonians with two independent
Hilbert spaces. The resulting model has a staggered structure due to
spin-flipping processes $t_{so}$ and cross-Andreev reflections $\Delta_{CAR}$ between neighbouring dots. Our central result is the phase diagram of a short chain consisting of four QDs and coupled to two external reservoirs, obtained by means of the Green function in
chiral Majorana representation. The modulus of the retarded Green function, probing the whole chain and calculated for zero energy, is shown to contain information on
topology and spatial character of Majorana zero modes. The features observed in the Green function nicely agree with those obtained from the transfer
matrix approach. In particular the region in parameter space in which Majorana zero modes display oscillatory wave functions are well reproduced. Likewise the borders of the
fermion parity changes obtained by the Green function agree with those obtained by other means.
Read the full abstract ▾
Atmospheric and Oceanic Physics
The impact of feature engineering and an optimisation framework for ocean colour machine learning
Edson Silva, Julien Brajard, Simon Cappe et al. (+2 more)
Machine learning (ML) is widely used for the development of ocean colour
algorithms, but most studies focus on model parameter training and hyperparameter tuning. The optimisation of the data that feeds the models - i.e., Feature Engineering (FE) - is not fully explored. We assess the impact of FE in ocean colour machine learning models and we propose an optimisation framework that includes seven sequenced levels of data transformation: i. band choice, ii. log scaling, iii. spectral shape normalisation, iv. index extraction, v. principal component analysis, vi. feature scaling, and vii. zero-to-one scaling. We demonstrate the application for Multi-layer perceptron, Support Vector Machines, and eXtreme Gradient Boosting Trees on Sentinel-3 OLCI observations in the Norwegian coastal waters. The models are trained to estimate Chlorophyll-a concentration [Chl-a] and Secchi disk depth (Zsd). Results show that accuracy is highly variable among FE found in six studies using Sentinel-3 OLCI and the ones that we optimise. The R range from 0.01 to 0.55 for [Chl-a] and from 0.15 to 0.68 for Zsd, where the optimised FE shows the top results. The ML models with optimised FE could also improve by two times the R and reduce up to 63% of the mean absolute error when compared to CHL_OC4ME and CHL_NN standard
algorithms. Nevertheless, no common optimised FE is found for all target variables and ML models, suggesting that FE optimisation is necessary for each application. Therefore, our proposed framework can be key for improving the accuracy of water quality monitoring in coastal waters.
Read the full abstract ▾
All authors Edson Silva, Julien Brajard, Simon Cappe, Lasse H. Pettersson, François Counillon
Instrumentation and Methods for Astrophysics
A dual-polarization whitened-template trigger for real-time radio detection of extensive air showers
Qader Dorosti, Alperen Aksoy, Ilja Bekman et al. (+7 more)
Autonomous
radio detection of extensive air showers requires reliable discrimination of their characteristic signals from transient interference, with decisions made in real time under stringent hardware constraints. We present a compact dual-polarization trigger developed using detector-folded air-shower simulations and measured
radio backgrounds from the Auger Engineering
Radio Array. The method combines the characteristic shape of air-shower pulses with measured background statistics to construct a filter that distinguishes air-shower signals from
radio interference. On an independent validation
dataset, it achieves 96% signal efficiency at a frame-equivalent background trigger rate of 3.12 kHz, substantially outperforming conventional amplitude thresholding and unwhitened template matching. Its robustness is further investigated using recordings acquired at different times from geographically distributed stations exposed to heterogeneous
radio interference. Transferring the unchanged filter between these environments requires adjusting the trigger threshold to the recently measured background conditions to control the background trigger rate. With threshold updates every 1 ms, the achieved rates range from 35.2 to 41.4 kHz for a nominal target of 35.7 kHz, demonstrating effective rate control across the tested environments while maintaining sensitivity to air-shower signals. The compact trigger architecture meets the timing constraints of a field-programmable gate array at 200 MHz, supporting its feasibility for autonomous
radio detection.
Read the full abstract ▾
All authors Qader Dorosti, Alperen Aksoy, Ilja Bekman, Markus Cristinziani, Eric-Teunis de Boone, Vesselin Dimitrov, Chimezie Eguzo, Stefan Heidbrink, Stefan van Waasen, Andre Zambanini
High Energy Physics (Theory)
Massive spin-2 supermultiplet and supergravity
Yu. M. Zinoviev
In this work, we consider the interaction of massless $N=1$ supergravity with a massive (2,3/2,3/2,1) supermultiplet, as a possible candidate for a supersymmetric extension to bigravity. A gauge invariant description for massive
spin-2,
spin-3/2 and
spin-1 fields is used. As a result of this, ambiguities arise related to possible field redefinitions, which are fixed by using a recently proposed method based on unfolded equations, and by restricting ourselves to interactions with the minimum number of derivatives (two for bosonic and one for fermionic vertices). It appears that this completely fixes the entire construction.
Read the full abstract ▾
Earth and Planetary Astrophysics
Quasi-diurnal Kelvin Wave Observed in the Atmosphere of Mars by the Pressure Sensor on the InSight Lander
Anzu Asumi, Jorge Hernández-Bernal, Kaoru Sato et al. (+1 more)
During the initiation phase of Martian
dust storms, a spectral signature of a zonal wavenumber 1 normal mode Kelvin wave (K1) has been observed in several surface pressure records. However, the K1 signal has not been extracted directly since its eigenfrequency is close to that of the diurnal tide, making their separation difficult. We apply singular spectrum analysis to more than one Martian year of InSight surface pressure observations, including the MY34 C
dust storm (C34). This analysis enables us to directly extract the transient K1 signal. Clear K1 signals appear during the Northern-Hemisphere spring and autumn with the average amplitudes of around 2 Pa. They reach 8 Pa during the C34 storm, which is substantial compared with a simultaneous diurnal signal (S1) maximum of 39 Pa. Near the peak time, K1 and S1 are in phase, and unexpectedly the S1 period shortens to 23.5 Mars hours. Subsequently, K1 rapidly decays and the S1 period recovers to 24 Mars hours. The phase relation between K1 and S1 as well as the S1 period shortening indicates that a resonance occurred between S1 and K1. Comparison with simulations at the model grid point closest to the InSight landing site shows that the Mars Planetary
Climate Model realistically reproduces the observed characteristics of the surface pressure variations.
Read the full abstract ▾
All authors Anzu Asumi, Jorge Hernández-Bernal, Kaoru Sato, Aymeric Spiga
Chaotic Dynamics
Intermittent Flocking and Fractal Collective Order Induced by Time-Varying Delays
David Müller-Bender and Rahil N. Valani
Time-varying interaction delays are ubiquitous in active matter, yet their collective effects remain largely unexplored. We show that active particles with internal dynamics and Vicsek-like delayed
alignment exhibit intermittent flocking, characterized by long episodes of coherent motion interrupted by brief disordering events. This collective behavior arises from laminar chaos, a form of chaotic dynamics unique to systems with time-varying delays. Changing only the delay parameters qualitatively reshapes collective motion, producing fractal changes in global flocking order. Our results establish the temporal structure of interaction delays as a new control parameter for active matter.
Read the full abstract ▾
Soft Condensed Matter
A solvent-flux theory for nonequilibrium swelling dynamics of thermoresponsive microgels
Arturo Moncho-Jordá, Alessandro Patti, Fabián A. García-Daza et al. (+1 more)
Thermoresponsive microgels undergo large reversible size changes as temperature alters solvent quality. Predicting their nonequilibrium swelling and deswelling kinetics is challenging because
polymer volume fraction, mechanical response, and solvent transport evolve during large volume changes. Here we develop a solvent-flux theory for the dynamics of a spherical microgel. The radius-change rate is driven by the osmotic-pressure imbalance across the particle boundary and resisted by water transport through the
polymer network, yielding a nonlinear equation for the global swelling coordinate and a state- and temperature-dependent swelling
diffusion coefficient, $D_{\mathrm{SW}}(\phi,T)$. In the linear-response regime, the theory recovers Tanaka–Fillmore exponential relaxation and the scaling $\tau_\mathrm{SW}\sim R_{\mathrm{eq}}^2\gamma/K_{\mathrm{eq}}$, while providing a microscopic interpretation of the
polymer–solvent friction coefficient $\gamma$. Beyond this limit, the model retains quadratic size scaling while accounting for state-dependent transport and mechanics. For pNIPAM microgels, it predicts asymmetric pathways, with deswelling faster than swelling over the same temperature interval. Finite thermalization produces a crossover from a microgel-controlled to a thermalization-controlled regime, in which the apparent relaxation time grows linearly with the external thermalization time and hysteresis-like loops emerge in the radius–temperature plane. A
stochastic extension based on the Smoluchowski equation predicts transient broadening of the radius distribution during collapse, with maximal fluctuations in the volume-transition region. The theory links solvent transport, nonlinear swelling dynamics, thermalization effects, and nonequilibrium size fluctuations in responsive microgels.
Read the full abstract ▾
All authors Arturo Moncho-Jordá, Alessandro Patti, Fabián A. García-Daza, Alejandro Cuetos
Cosmology and Nongalactic Astrophysics
A Prediction for DESI Full-Shape: Increasing Tomographic $\Omega_m(z)$ Trend
Eoin Ó Colgáin and M. M. Sheikh-Jabbari
To confirm $\Lambda$CDM deviations are due to missing physics (not systematics), one should demonstrate that the model fitting parameters exhibit qualitatively similar
redshift drift across independent observables. This is the only way one guarantees new physics. Here, we show that a recent Dark Energy Spectroscopic Instrument (DESI) DR2 Full-Shape (FS) modelling Lyman-$\alpha$ constraint at $z_{\rm eff} = 2.33$ combined with earlier DR1 FS modelling constraints with $0.295 \leq z_{\rm eff} \leq 1.491$ leads to a straight line $\Omega_m(z) = m z + c$ with slope $m = 0.022 \pm 0.012$, $1.8 \sigma$ removed from constant $\Omega_m$. Akaike Information Criterion and
Bayesian evidence confirm that constant $\Omega_m$ and increasing $\Omega_m(z)$ are statistically indistinguishable. Through the $Om(z)$ diagnostic, we review how increasing and decreasing $\Omega_m(z)$ trends map to phantom and quintessence dark energy (DE) regimes, respectively. While FS modelling constraints map to phantom DE, the decreasing and increasing $\Omega_m(z)$ trends in DESI BAO and DESI with external data make a phantom crossing inevitable. Since dynamical DE is but one interpretation for $\Omega_m(z)$ trends, it is imperative that different
datasets converge on their $\Omega_m(z)$ trends before one jumps to physical conclusions. We forecast how DESI FS modelling $\Omega_m$ constraints will improve up to the final data release and explore the implications for model selection.
Read the full abstract ▾
Optics
A Non-Hermitian Biorthogonal Encoding Paradigm for Physical-Layer Secure Computational Imaging
Xi-Hao Chen, Kan-Xu Jia, En-Rui Zhang et al. (+5 more)
The conventional paradigm of computational imaging, rooted in Hermitian systems, is fundamentally constrained by rigid orthogonal basis transformations, which bottleneck the balance between reconstruction fidelity, computational load, and physical-layer security. In this work, we propose a generalized secure computational imaging framework based on non-Hermitian biorthogonal
symmetry breaking. By mapping spatial information into a biorthogonal operator space, we establish an asymmetric sensing architecture governed by distinct left-basis $\langle\phi_{m}\vert{}$ and right-basis $\vert{}\psi_{n}\rangle$ modes, satisfying the biorthogonality relation $\langle\phi_{m}\vert{}\psi_{n}\rangle = \delta_{mn}$. Within this
manifold, precise tuning of the non-Hermitian parameter $\gamma$ establishes a physical-layer cryptographic gate, where high-fidelity
retrieval is exclusively enabled by matching the dual basis; any parameter mismatch triggers deterministic inter-modal crosstalk that effectively neutralizes unauthorized access. Notably, this architecture intrinsically supports direct, iteration-free image
retrieval across a wide range of sampling ratios, significantly reducing the computational overhead compared to conventional iterative reconstruction. We validate this framework on a single-pixel imaging platform, demonstrating a fundamental paradigm shift: by
embedding security directly into the measurement physics, we transform image
retrieval from a software-dependent task into a parameter-sensitive physical decryption process that ensures architecture-intrinsic confidentiality.
Read the full abstract ▾
All authors Xi-Hao Chen, Kan-Xu Jia, En-Rui Zhang, Yi-Zhu Zhang, Xin-Peng Wei, Bu-Ran Yu, Qian-Qian Bao, Shao-Ying Meng