Papers

Cardiovascular magnetic resonance (CMR) provides comprehensive cardiac assessment but remains underutilized because of the complexity of acquisition, post-processing, and interpretation. Existing artificial intelligence (AI) methods address isolated tasks, limiting clinical integration. We present ORION-CMR (On-scanner Reporting with Integrated fOunda-tioN Model), the first clinically evaluated scanner-native end-to-end CMR foundation model. Pretrained on 12,896,733 CMR images from 9,258 studies, ORION-CMR performs sequence classification, ventricular function assessment, late gadolinium enhancement (LGE) detection, binary and multiclass disease classification, and local large language model-based report generation in approximately 90 seconds. The framework. was evaluated on public benchmarks and clinically validated in a multi-vendor cohort of 68 subjects with normal examinations, congenital heart disease, dilated cardiomyopathy, and myocardial infarction. ORION-CMR outperformed supervised baselines and the previously published CMR foundation model (CMR-FM), achieving state-of-the-art performance for LGE classification and scar segmentation. Clinical evaluation achieved an AUC of 0.96 for normal-versus abnormal classification and 0.88 for multiclass disease classification, while generated reports demonstrated 81.4% agreement with expert interpretation. These results demonstrate the feasibility of real-time scanner-native AI-assisted CMR analysis and automated report generation.

We give an explicit non-random example of nonadditivity of minimum output von Neumann entropy. The proof uses a finite-dimensional construction which imitates free Haar unitary behavior. The same channel gives a violation of additivity for the minimum output Rényi-$p$ entropy for any $p\in[1,\infty]$. Additionally, given any $p_0>0$ and $\mathfrak g>0$, we extend the construction to obtain an explicit non-random channel which has entropy gap $\ge\mathfrak g$ uniformly over $p\in[p_0,\infty]$.

Lee-Yang theorems are a powerful tool for studying many-body systems, with applications ranging from analyzing phase transitions to proving the efficiency of certain classical and quantum algorithms. In this work, we prove a Lee-Yang zero-freeness theorem for the partition function of a broad class of interacting fermion models, implying the existence of a provably efficient quantum algorithm for estimating their ground-state energies. This class includes several well-known models such as the attractive Hubbard model, repulsive Hubbard model on bipartite graphs, and the interacting Hofstadter model. Our results also rigorously establish the nonexistence of phase transitions in these models in the presence of a nonzero local external field.

We show that anomaly-free second-order supersymmetry (SUSY) in quantum mechanics admits a projective-geometric formulation in terms of a projective connection and a vector field preserving it. Once the physical coordinate and energy origin are fixed, these data determine the partner Hamiltonians and supercharges; the field's quadratic invariant fixes the central parameter and candidate singlet energies. The fixed-point structure of this field yields explicit criteria for smooth continuation of the quantum operators through superpotential zeros. The classically fictitious similarity transformation selects affine data whose covariant factors generate the Schwarzian quantum correction. Dimensional reduction of a Riemannian model reproduces these affine data through the volume measure, while a coordinate adapted to the selected field implements coupling-constant metamorphosis. A one-gap Lame pair illustrates the relation between the SUSY auxiliary geometry and the Gelfand-Dikii-Virasoro structure governing physical solution products. Its Lax-Novikov integral acts on Schrodinger solutions through the first-order action of a projective stabilizer; in the reflectionless limit it becomes proportional, in the physical coordinate, to the auxiliary third Bol operator.

Complex networks balance metric wiring costs against functional routing demands, rarely conforming to idealized dichotomies of pure planar grids or unconstrained topologies. Yet, existing latent-space models remain computationally bottlenecked by stochastic sampling on small, unweighted graphs. Here, we formulate a scalable generative framework to solve the inverse problem of spatio-functional inference in weighted networks. By coupling explicit metric spaces with an unobserved latent geometry, we jointly reconstruct hidden coordinates and infer a coupling parameter $\lambda \in [0, 1]$, quantifying the connectivity propensity explained by functional affinity conditioned on metric distance decay. Our deterministic pipeline pairs a physics-informed spectral residual initialization with hybrid first- and quasi-Newton optimization. Across diverse empirical systems, the framework reveals a continuous spatio-functional spectrum. In the Drosophila melanogaster whole-brain connectome, it resolves an architectural progression from metric-constrained sensory circuits to specialized associative and chemo-affinity neuropils. In the continental European power grid, line pruning preserves a strictly metric baseline ($\hat{\lambda} \approx 0$), whereas topological rewiring drives a sharp surge in $\hat{\lambda}$, demonstrating that macroscopic component connectivity can mask spatial degradation. Finally, tracking global aviation throughout the COVID-19 pandemic captures dynamic regime shifts toward localized metric connectivity, establishing a unified diagnostic to probe structural organization and resilience in spatially embedded networks.

Four out of 10 adults aged 30 years or older in the USA are impacted by periodontal diseases which span a spectrum of inflammatory conditions. Currently, a subjective, invasive and a semi-quantitative approach, termed bleeding on probing, is employed in clinics for inflammation assessment. The long-term goal of this study is to fill the current clinical diagnostic gap in dentistry by proposing quantitative ultrasound (QUS)-based biomarkers for inflammation diagnosis and monitoring. Here, as one of the early works in this area, we investigated two QUS parameters for characterizing periodontal inflammation in gingival tissues using a longitudinal preclinical porcine study: attenuation coefficient slope (ACS) and backscatter intensity (BSI). Our study included eight pigs imaged intraorally (24 MHz) at four bi-weekly timepoints from week 0 (healthy) to week 6 (post inflammation inoculation) at their interproximal sites of the third premolars (PM3-Mes) from all quadrants. Moreover, we compared gingival tissues surrounding a tooth at lingual/palatal side versus buccal side at the second molar (M2-Dis) in healthy condition. Our results showed that gingival ACS at all inflammation timepoints were significantly lower than healthy gingival ACS (1.69 \pm 0.53 dB/cm.MHz) using a mixed effect analysis (week 6: 1.08 \pm 0.25 dB/cm.MHz). Longitudinal comparison of BSI did not demonstrate any statistical significance. Gingival ACS and BSI at lingual/palatal versus buccal sides of M2-Dis did not exhibit any statistical significance. These ACSs were linearly correlated with R-squared = 0.89 and a correlation slope of 0.87. For BSI, Bland-Altman analysis demonstrated no difference in mean BSI, although variability was high. These findings highlight the promising potential of ultrasonography paired with QUS to complement current standard of care in dentistry.

We present a framework to advance analytical theory in the area of soft matter and multiphysics using assistance from AI. The framework emphasizes (i) setting "honesty rules", (ii) focusing on a few key papers that are used to formulate a problem of interest, (iii) specifying checks a priori, (iv) using only one task per session and keeping a running log of tasks, checks, corrections, and sessions so that a mistake is not propagated through a project, and (v) ensuring all decisions are approved by humans while AI focuses primarily on execution. The framework is applied to two distinct problems to create new knowledge, including (i) diffusiophoresis of a spherical particle in the presence of an arbitrary number of electrolytes at arbitrary Debye lengths, and (ii) analytical description of I-V curves, including overlimiting current, in bipolar membranes without including the water dissociation kinetics. Both of these problems are advanced analyses and would each typically require several months to a year's worth of effort, but were solved in a matter of a few days. However, the increased efficiency should be cautiously navigated to avoid cognitive offloading and ensure that AI-assisted results are used to extract human-readable insights instead of just reporting a new mathematical formula. The usage of AI is transparently presented. Finally, we also share brief thoughts on how to integrate AI tools in theoretical research during graduate education.

We determine the electrostatic Dirichlet-to-Neumann map of an arbitrary four-dimensional Majumdar–Papapetrou spacetime. For a minimally coupled spectator Maxwell field, the potentials of the disconnected extremal horizons may be prescribed independently, and the resulting flux charges are related by an exact capacitance matrix. If the centers have masses $M_A$ and coordinate separations $R_{AB}$, its entries are $C_{AA}=M_A+\sum_{B\ne A}M_AM_B/R_{AB}$ and $C_{AB}=-M_AM_B/R_{AB}$. The matrix is a positive diagonal term plus the weighted Laplacian of the complete graph of horizons, giving an exact common-mode and differential-mode decomposition of the field energy. The grounded Dirichlet Green function shows that a point charge partitions its flux among infinity and the horizons according to elementary harmonic measures. A direct translation of the multicenter Green function of Frolov and Zelnikov gives the diagonal completion used in their published Eq.~(68), whose component-resolved Gauss flux preserves the total horizon charge but generally transfers charge between horizons. The symmetric Green function that preserves every horizon charge instead contains the inverse of the full capacitance matrix. For a binary, the difference gives a finite, negative-semidefinite shift of the electrostatic self-energy and a corresponding exact self-force difference without an additional ultraviolet subtraction. We finally extend the response matrix, flux partition, and fixed-charge Green function to $D=n+3$ dimensions, where the graph weights acquire the universal factor $\pi^{n/2}/\Gamma(n/2)$.

It is an unnatural feature of the Standard Model that the difference between the baryon number $B$ and the lepton number $L$ is conserved, which implies an exact, global symmetry. We promote it to a naturally exact, local symmetry by coupling the difference $B-L$ to an Abelian gauge field. Gauge anomalies are cancelled by adding right-handed neutrinos $\nu_{R}$. They are not sterile in this case, which forbids the Majorana term, but we arrange for a $\nu_{R}$-mass by adding a Higgs-type 1-component complex scalar field. Thus we arrive at a well-motivated, modest extension of the Standard Model (SM). We investigate the field equations in the corresponding gauge-Higgs sector, involving both Higgs fields and the non-standard U(1) gauge field. This leads to a set of coupled, non-linear differential equations, which we solve numerically. We use cylindrical coordinates, thus focusing on the structures of cosmic strings. For a large variety of parameters, we identify the string profiles and energy densities. These profiles depend on the winding number of each of the Higgs fields. For our parameters, the characteristic string radii are below $10^{-3}~{\rm fm}$, and the string tension is not ruled out by observations of the Cosmic Microwave Background or gravitational waves. As an amazing peculiarity, we discover - for high winding numbers - “overshooting” and “co-axial” profile functions. In the latter case, the profile of the standard Higgs field changes its sign near the core of the cosmic string.

Bell-CHSH measurements with polarization-entangled photons are commonly used as nonlocality witnesses. Here we show that the same coincidence data can also provide a quantitative metrological certificate for optical retardance sensing. For a local birefringent phase encoded on one photon, we derive the classical Fisher information directly from experimentally accessible CHSH correlators and obtain a lower bound expressed in terms of the measured correlations and the phase derivative of the CHSH parameter. In the unbiased-marginal two-qubit regime, the canonical CHSH analyzer settings are shown to be simultaneously Bell-optimal and Fisher-optimal, saturating the quantum Fisher information for retardance estimation in the ideal case. We further analyze reduced visibility, phase noise, analyzer misalignment, and finite coincidence counts, and construct conservative lower confidence bounds that can be evaluated without quantum-state tomography. The results also clarify that Bell violation and metrological usefulness are distinct resources: nonzero Fisher information can persist below the CHSH-violation threshold. The protocol therefore enables a standard Bell-test data set to provide both a nonlocality benchmark and a statistically controlled sensitivity certificate for quantum polarimetry.

A self-consistent treatment of strong-field laser - plasma interactions suggests a heuristically valuable extension of the notion of nonlinear-optical susceptibility to perturbative regimes of stimulated light scattering in plasmas, offering powerful insights into stimulated-scattering-induced cross-beam energy transfer processes. These findings lay grounds for a unified treatment of stimulated light scattering across a vast area of optical physics, spanning from fiber optics and neutral gases to laser - plasma physics.

We present preliminary results of a study of galaxy sizes at redshift $z \gtrsim 5$ using the high-resolution, zoom-in FirstLight simulations. We obtain a redshift-independent, chevron-shaped stellar mass–size relation with a peak at $M^{\star} \approx 10^{8.5}~\mathrm{M}_\odot$. This relation is shaped by the individual evolution of galaxies, which undergo a phase of contraction at this mass scale triggered by a strong central starburst.

The Vlasov-Maxwell system with Newtonian particle transport is linearised about the Poisson equilibrium on $\mathbb{R}^3$, with the speed of light $c$ treated as a large parameter. For uniformly controlled initial data, with transverse fields that may remain of order one, the difference between the Vlasov-Maxwell perturbation and its linearised Vlasov-Poisson counterpart is bounded uniformly in time by their initial discrepancy plus a term of order $c^{-1}$. The same estimate holds for their scattering states, and the rate in $c$ is sharp. The longitudinal dynamics are governed by the same Volterra equation as in linearised Vlasov-Poisson and undergo Landau damping. The transverse fields exhibit Klein-Gordon-type dispersion, and control of their accumulated effect along free transport yields the uniform comparison.

The Green-Kubo (GK) method which is used to obtain the shear viscosity of a model liquid in equilibrium molecular dynamics (MD) often requires long simulation times to obtain acceptable statistics. This work extends the GK approach to include spatial correlations. The total shear stress in the GK expression is split into a grid of its components in contiguous volumes. In doing this, the autocorrelation of the total system stress can be rewritten as the cross-correlation of the subvolume stresses. This provides a novel real-space insight into the liquid structure, something previously only treated in Fourier space by liquid-state theory. A novel travelling wave like structure is exposed that is shown to be well fitted by a leading Gaussian pulse added to a second negative Gaussian for the bounce back. The fitting parameters include the wave position, magnitude and width which show deep insights into the liquid property. The wave moves at the speed of sound over short times before decreasing in speed with the square root of time, while the wave packet spreads out also as the square root of time. The magnitude is decreasing with form $t^{-3/2}$, a result with strong significance in the history of MD simulation. These fitted forms mean the entire spatial temporal response of the liquid can be modelled in closed form by fitting to data, with short term requiring MD and the long time and distances approximated by the Gaussian form. By limiting the correlation to localized interactions the longer range contribution, which essentially only contribute to the noise, can be eliminated. This looks like a promising approach to model viscosity by taking short MD runs and fitting the long time behaviour.

In 1936, the protostar FU Orionis began to brighten. Two years later, it was 100 times brighter and has not dimmed since. This object defined the class of FUor-type accretion bursts in protostars. Previous attempts to model FUors simulate isolated protostellar discs, thereby limiting the mass available to drive the burst and shortening its duration. However, these protostars are embedded within the interstellar medium, from which they actively accrete via accretion streamers. This work seeks the origin of FUors starting at interstellar medium scales. An unbiased search of star particles from a 25AU resolution star cluster formation simulation was performed to find FUor candidates. Most candidates were low-mass secondary stars in highly eccentric binaries, like FU Orionis. Zoom-in simulations down to 0.79AU resolution found candidates experience dramatic accretion suppression and bursts at the closest binary separation at periastron. Approaching periastron, the candidate's orbital speed becomes supersonic striping away nearby gas. After periastron, the orbital speed decreases allowing gas to accrete onto the candidate rapidly via Bondi-Hoyle-Lyttleton (BHL) accretion. BHL accretion tails form behind the candidate and appear as accretion streamers. This dramatic suppression and burst near periastron is a physical mechanism for strong variable accretion in embedded young eccentric binaries. This mechanism also implies that FU Orionis returned to its former accretion rate.

Generative AI tools are being widely taken up by students in their physics courses and beyond, often before instructors and institutions can develop policies and effective approaches for the use of these tools. Building on a framework for change in the era of AI, we developed and implemented a faculty learning community to help a university physics department address these challenges collectively. Over six biweekly sessions, faculty worked through course policies, classroom conversations about AI, AI-integrated coursework tasks, and assessment. Each session shared a common structure: we presented local data and department-sourced materials, tested them in small groups, and discussed them together, emphasizing durable pedagogical approaches over specific tools and platforms, and leading with evidence of students' own AI use. The series produced a shared, evolving repository of resources for faculty to draw on. This workshop provides an adaptable, theoretically informed model for a faculty learning community that departments can build on.

We describe the first Galactic-scale extreme-precision radial velocity (EPRV) survey and outline our goals of measuring Galactic accelerations and deriving constraints on the dark matter distribution in our Galaxy. We are targeting quiet subgiant stars within a kiloparsec in radius of the Sun and about 2 kiloparsec in vertical height relative to the Galactic mid-plane. The observations described here were carried out using the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO) at the Very Large Telescope (VLT), between 2021-2025. We began by operating at a typical RV precision of $\sim$ 70 cm/s to select quiet stars from stellar activity indicators, and are now operating at $\sim$ 50 cm/s. We selected stars with low stellar jitter (determined from their RV scatter as a function of epoch) with the goal that they yield a measurement of the Galactic acceleration on approximately a decade timescale. We refer to this as our “gold" sample. We also identify stars with possible companions (either brown dwarfs or planetary companions) or hitherto unknown stellar binaries that we have culled from our survey. For a few cases, we present initial constraints on the companion mass and orbital period. We also present the photospheric and fundamental stellar parameters for our “gold" sample of sub-giant stars. This first Galactic-scale EPRV survey provides a pathfinder for next-generation surveys with extremely large telescopes, opening the possibility of directly mapping the gravitational acceleration field across the Milky Way and potentially beyond.

We prove that a smooth, regular, asymptotically flat stationary vacuum black hole has a nonextremal Kerr exterior if no null geodesic orthogonal to its stationary Killing field is trapped, establishing the rigidity conjecture of Alexakis, Ionescu, and Klainerman. In the rotating case, we start with the rotational Killing field constructed near the bifurcation sphere and study a maximal domain carrying its complete circle action. The main difficulty is to recover boundary regularity and the curvature condition needed for local Killing extension. We derive uniform estimates along complete rotational orbits from nontrapping and combine them with convexity along short null geodesics. These estimates show that a nonempty remaining boundary in the ergoregion is a timelike photon surface for the stationary quotient metric. Its null geodesics lift to spacetime null geodesics orthogonal to the stationary field. The vacuum circularity identities give their continuation through contact with the ergosurface, keeping their stationary projections in a compact set. This contradicts nontrapping and yields the global rotational symmetry required by black hole uniqueness.

Reservoirs with the same mean relaxation rate can be indistinguishable at the level of average energy transport while producing different fluctuations. We study a bosonic mode coupled to hot and cold Poisson streams of thermal ancillas through finite beam-splitter collisions. The averaged evolution is a compound-Poisson semigroup generated by finite Gaussian event channels. Its nonequilibrium steady state is an exact mixture of thermal states governed by a random affine fixed point. Consequently, the mean-occupation dynamics and bath-resolved mean heat currents coincide with those of the matched continuous Lindblad reservoir, whereas higher correlations retain the collision strength. For equal collision transmissivities, we derive an exact superthermal bunching law controlled by the temperature contrast and collision strength. We also obtain the asymptotic rates of the first two heat cumulants for an ideal stationary event-resolved two-point-measurement record and separate local one-collision contributions from temporal correlations. Fock-space diagonalization and Monte Carlo trajectories validate the formulas and connect full resets to the weak-collision Gaussian limit.

On 7 and 8 September 2026 programmatic search produced singularities: a forced Navier-Stokes singularity at every fixed viscosity, statements (C) and (D) of the Clay problem, and two Euler singularities. The unforced problem, statements (A) and (B), stands open, and a search for it needs a target. This paper fixes one: the positive defect problem, that a Leray-Hopf solution from smooth data on the periodic cube loses energy on a finite window, at fixed viscosity, beyond what viscosity removes. A positive defect implies blowup and so a negative answer to statement (B); the converse is not known. The paper proves the target equivalent to a floor on the energy flux through the Littlewood-Paley shells, the Fourier-side form of the coarse-grained flux of the Onsager theory of turbulence, averaged over the window; states necessary conditions on a candidate: a singular time of Type II in velocity, energy concentrating on a set of zero length, a pressure outside L^2, a velocity outside the Onsager-critical class L^3_t B^{1/3}_{3,c_0}, an obstruction to collapse onto a fixed steady Euler profile; and states what cannot certify one: no finite computation witnesses a Galerkin-uniform ceiling, and selection and forcing return the question to a positive defect. A pseudo-spectral search at 128^3 and 256^3 shows which condition of the reduction binds: the fine-shell flux floor holds to within 1 to 6 percent of the ceiling for a third of a turnover time, and fails in scale at the Kolmogorov wavenumber, so a candidate must differ from generic turbulence in the depth of its cascade, not in its timing. Every implication not marked otherwise is a theorem in Lean 4 over Mathlib; the library contains no Navier-Stokes object, and the equation enters only through hypotheses.

The Voyager spacecraft have been detecting plasma oscillations of a few kHz for over 40 years. However, there is still no widely accepted hypothesis for the astrophysical source of the oscillations. Having entered the local interstellar medium, these detections have persisted, adding to the challenge of identifying the astrophysical source. Neutron stars were one of the earliest hypothesized candidates of the electromagnetic radiation responsible for the detected plasma oscillations, but no theoretical mechanism could be identified to explain the frequency of the oscillations. We explore the recently developed theory of co-production of electromagnetic radiation in gravitational wave backgrounds as a possible source of these low-frequency oscillations and investigate whether neutron stars could be the astrophysical source.

In this paper we study the Borel summability and quantum modularity of the free energy computed by refined topological recursion on the Weber-type refined spectral curve. On the one hand, we verify expected properties, namely, Stokes rays come in a pair and the Borel-Laplace sum of the free energy coincides with the Barnes double gamma function. Somewhat unexpectedly, on the other hand, we prove that the generating function of the Stokes constants along each ray is a Jacobi quantum modular function. Our proof suggests that quantum modularity may be a general feature of refined topological recursion, applicable beyond the Weber-type refined spectral curve.

The continuity equation serves as a fundamental principle for mass transport in continuous media. While its mathematical structure mirrors that of probability transport and the Liouville equation, an informational interpretation of macroscopic fluid flow is less commonly explored in engineering contexts. This paper treats fluid density as a spatial probability density function, modeling macroscopic motion as the continuous transport of uncertainty. I derive the temporal evolution of Shannon entropy under general flow conditions, establishing how entropy generation depends on macroscopic compressibility and microscopic diffusion. Microscopic diffusion is shown to act as a strictly positive entropy source governed exactly by local Fisher Information. Furthermore, the framework yields an explicit algebraic scaling law characterizing the equilibrium thickness of compressive mixing layers at a local Peclet number of unity. The theoretical model is computationally validated through finite-difference simulations of one-dimensional canonical flows and advection-diffusion within a three-dimensional, spatially varying Arnold-Beltrami-Childress (ABC) flow, yielding a mean relative error of $0.001$. The framework provides an analytical perspective on thermodynamic irreversibility, with potential applications to turbulence modeling, thermal entropy generation in heat exchangers, in-cylinder mixing in internal combustion engines, and aerodynamic flows.

We employ equation-driven, physics-constrained deep learning to solve the fixed-boundary Grad-Shafranov (GS) equilibrium problem, constructing axisymmetric magnetohydrodynamic equilibria with tokamak-relevant characteristics. Equilibria across linear (Solov'ev) and nonlinear profile functions are constructed using Physics-Informed Kolmogorov-Arnold Networks (KANs) that approximate GS solutions while satisfying appropriate boundary conditions. A highly nonlinear pressure profile recreating high-confinement mode phenomenology, such as pressure pedestals and significant bootstrap current components, is also considered. To enable efficient convergence, guided training schemes are employed, specifically homotopy-based continuation curriculum learning and transfer learning via pretrained networks. While computing nonlinear equilibria employing standard Multi-Layer Perceptrons under unguided physics-informed training remains an elusive or computationally inefficient task, our framework overcomes this limitation. Specifically, we demonstrate that the combination of three key elements, namely KAN architecture, guided training schemes, and the self-scaled Broyden optimization method, enables stable, efficient, and accurate equilibrium computation with simultaneous profile parameter identification in view of equilibrium constraints.

A physics-informed latent neural operator framework is proposed for three-dimensional compressor cascade flow prediction. The proposed method combines a Transolver-based latent encoder, which extracts compact global latent representations of flow conditions from point-cloud CFD data, with a coordinate-based PINNs decoder to reconstruct continuous flow fields while incorporating physics-informed residual constraints during training. The results show that the proposed framework can accurately reconstruct pressure and velocity distributions of complex three-dimensional cascade flows and maintains good prediction capability under previously unseen operating conditions. The present method demonstrates promising potential for efficient CFD surrogate modelling and aerodynamic prediction in turbomachinery applications.

We present a model of freeze-in dark matter (DM) and baryogenesis in which the new particles are a TeV-scale electroweak-doublet vector-like fermion (VLF) and two gauge-singlet Majorana fermions that constitute the DM, the heavier one with a mass in the tens-to-hundreds of keV range. Feeble Yukawa couplings of the VLF to the DM and the Standard Model Higgs doublet induce freeze-in production of the DM via VLF decays in the early universe. Due to a CP-violating phase in these couplings, DM propagation and rescattering induce opposite charge asymmetries in the VLF and SM sectors. Even in the absence of $B-L$ violation, the VLF asymmetry guarantees a baryon asymmetry once in-equilibrium SM interactions are taken into account. A relatively small conversion factor from VLF asymmetry to baryon asymmetry is balanced by a more direct asymmetry generation mechanism than in other minimal models of freeze-in baryogenesis. The observed DM energy density requires the heavier DM particle to remain well out of equilibrium throughout production. This allows us to map out the VLF mass-lifetime space using a novel perturbative calculation of the baryon asymmetry. We find that the model is already significantly constrained by LHC searches and structure formation probes, which will continue to test interesting parameter space in the coming years. The addition of VLF Yukawa couplings not involving the DM breaks $B-L$ and greatly expands the viable parameter space, while inducing potential signatures from dark matter decay and lepton flavor violation.

Radiation drag from inverse-Compton scattering of an external radiation field changes the acoustic dispersion relation of a relativistic fluid. We derive the linear dispersion relation and show that, depending on the electron distribution and fluid sound speed, radiation drag either damps both modes or damps one while driving the other unstable. The unstable growth is robust at short wavelengths but slow and overdamped at long wavelengths, where the linear analysis is limited by the background acceleration. The resulting growth and damping rates are of order the bulk radiative acceleration rate, so whenever radiation drag is important for the background flow, its effects on fluid perturbations are also important. A purely damped region exists for a wide range of parameters. Radiation drag also makes acoustic waves dispersive: The phase speed deviates from the ordinary sound speed at longer wavelengths, and approaches the sound speed at short wavelengths. We validate the derived rates using special-relativistic hydrodynamic simulations. We apply the derived relation to astrophysical jets such as gamma-ray bursts, blazars in the broad-line region of the host active galactic nucleus, and quasar jets traveling through the CMB and galactic radiation field. We find that the derived instability, damping and dispersion may be relevant across a range of relativistic outflow conditions.

The flux of protons slow-extracted from the CERN Super Proton Synchrotron (SPS) to the North Area experiments is limited by the induced radioactivity of the beam lost on the electrostatic septum during the third-integer resonant extraction. Crystal shadowing, in which a thin bent silicon crystal deflects the portion of beam that would otherwise impinge on the septum wires, has been in operation at the SPS since 2021, and a single crystal at a non-local position halved the extraction losses, short of the fourfold reduction that the activation budget of the future high-intensity operation calls for. In this paper, the design, deployment and operation of a 3-crystal Multi-Volume Reflection Array (MVRA) at the non-local position in the fourth long straight section (LSS4) are presented. The array geometry was designed by Multi-Fidelity Bayesian Optimization (MFBO), combining a multilayer-perceptron surrogate with full particle tracking, which predicts a fourfold loss reduction with three crystals and up to tenfold with an ideally aligned array of four to five. Measurements with beam confirm the prediction: at its optimum the as-built array reduces the losses by the predicted factor of four, and beam dynamics simulations matched to the measured position and angle scans reproduce them to a few per cent. The array has since been used in physics production, held on its operating plateau by an extremum-seeking controller, with a median loss reduction by a factor of 3.6 over 0.1 million extraction cycles relative to the pre-shadowing baseline. The remaining margin to the target, the limitations of the present installation and the upgrade to a 4- or 5-crystal array are discussed.

Twin-beam (TWB) states generated by parametric down-conversion exhibit strong photon-number correlations that can be exploited for quantum communication. In the mesoscopic regime, these correlations can be directly investigated using photon-number-resolving detectors, such as silicon photomultipliers (SiPMs). Their nonclassical nature is quantified by the noise reduction factor (NRF), which provides a witness of quantum correlations and a means of monitoring channel security. In this work, a quantum communication protocol based on TWB states, originally proposed for binary encoding, is extended to a four-state scheme capable of transmitting two bits per use. Information is encoded by combining two mean photon-number values and two mode numbers of thermal noise superimposed on one arm of the twin beam, defining four distinguishable states in the (m,R) plane. While the mean detected photon number enables the retrieval of one bit, the NRF provides discrimination of the second bit and a security check against intercept-and-resend attacks, which introduce additional noise and degrade the quantum correlations. The protocol is investigated through two experimental measurement campaigns. First, the twin-beam source is characterized in terms of photon-number statistics, NRF, and detection efficiency to establish the operating conditions of the communication channel. Subsequently, the four-state protocol is implemented and evaluated through the analysis of state distributions and their 95% confidence regions, error probability as a function of sample size, and a comparative assessment of machine learning classifiers for state discrimination. Finally, the response of the NRF to an intercept-and-resend attack is investigated to assess the protocol's ability to detect eavesdropping.

The cancer specificity of serum prostate-specific antigen (PSA) motivates complementary, non-invasive approaches to prostate disease assessment. Building on reported high-resolution terahertz (THz) analysis of urine-derived products, this review integrates spectroscopic evidence with a statistical reanalysis of clinical data from 24 patients with prostate cancer (PC) and 14 with histologically confirmed benign prostatic hyperplasia (BPH). Nonparametric statistical comparison shows higher PSA levels in PC, while overlapping patient distributions and receiver-operating-characteristic analysis with bootstrap uncertainty estimation demonstrate incomplete discrimination from BPH. Fast frequency-sweep spectroscopy characterizes urine-derived volatile and thermal-decomposition products, distinguishing compounds shared between groups from candidate PC-associated assignments, including glycolaldehyde, butyronitrile, pentanenitrile and methyl isocyanate. Glycolaldehyde has been detected by urinary carbonyl profiling, while benzaldehyde and phenol have been reported in urinary volatile studies. Related aldehydes identified by gas chromatography-mass spectrometry and glycine-associated metabolites reported in proton nuclear magnetic resonance studies provide complementary chemical and metabolic context. These correspondences support plausibility of THz findings without establishing PC specificity. Together, the dataset, statistical assessment and comparative literature synthesis support THz urine spectroscopy as a platform for molecular discovery and candidate prioritization. Standardized sample preparation, separation of native urinary constituents from processing-derived products, and validation in independent cohorts remain necessary.