High Energy Physics (Theory)
Quiver BPS Indices from Crystal Profiles
Jiakang Bao and Masahito Yamazaki
We derive new exact formulae for
elliptic genera in two spacetime dimensions with $\mathcal{N}\ge 2$ supercharges, as well as their one- and zero-dimensional counterparts (for Witten indices and
matrix-model partition functions). Our results are written as a discrete sum over
geometric/combinatorial structures of
crystals introduced previously by the authors. The contribution from each
crystal may be expressed in terms of the boundary data of a finite substructure of the
crystal called the molecules. Our results provide vast generalisations of the celebrated Nekrasov partition function enumerated by the Young diagrams, and uncover new combinatorics underlying the
crystal melting. We also analyse the thermodynamic limit of
crystals arising from two-dimensional $\mathcal{N}=(0,2)$ theories associated with toric Calabi-Yau fourfolds, where a projection of the Calabi-Yau geometry emerges in the limit.
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Statistical Mechanics · Cross-listed from cs.IT
The Informational Cost of Structure: Representational Complexity in Networked Dynamical Systems
Cyril Rommens, Pietro Traversa, Guilherme Ferraz de Arruda et al. (+1 more)
How much information is required to represent a dynamical system in terms of an interaction structure and an
evolution rule? We address this question using algorithmic information theory. We introduce Representational Complexity, the excess description length of a structure-plus-rule model relative to the shortest possible description of the dynamics itself. This intrinsic description defines a universal lower bound: no exact structural representation can be more concise. If arbitrary rules are allowed, graphs, hypergraphs, and other formalisms can all reach this bound by shifting information between structure and dynamics, so expressiveness alone cannot distinguish them. Meaningful differences arise only when scientific modeling restricts the admissible structures and rules. Within this setting, we identify conditions under which graph and hypergraph descriptions are informationally equivalent, and show how graph-preferred, hypergraph-preferred, and mixed regimes can emerge when those conditions are relaxed. Because Kolmogorov complexity is not computable, we complement the formal results with explicit description-length estimates. Our framework reframes the choice of network representation as a question of informational cost and mechanistic transparency rather than universal expressive power.
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All authors Cyril Rommens, Pietro Traversa, Guilherme Ferraz de Arruda, Yamir Moreno
Instrumentation and Methods for Astrophysics
Machine Learning and the SKA for Cosmic Dawn and the Epoch of Reionization
Anshuman Acharya, Michele Bianco, Daniela Breitman et al. (+18 more)
When operational, the SKA will generate unprecedented amounts of data and provide exquisite sensitivity for 21 cm
tomography of
Cosmic Dawn (CD) and the Epoch of Reionization (EoR). With this comes opportunities for new data-driven
algorithms that unlock new methods for instrument modelling, data analysis, theoretical simulation, and inference for understanding the high-
redshift universe. In this chapter, we provide an overview of some machine learning
algorithms that have been proposed for CD and EoR science with the SKA
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All authors Anshuman Acharya, Michele Bianco, Daniela Breitman, Huaxi Chen, Abhirup Datta, Kangning Diao, Sambit K. Giri, Caroline S. Heneka, Nicholas Kern, Adrian Liu, Yashrajsinh Mahida, Suman Majumdar, Samit Kumar Pal, Shulei Ni, Yannic Pietschke, Davide Piras, Abinash Kumar Shaw, Hayato Shimabukuro, Ce Sui, Anshuman Tripathi, Xiaosheng Zhao
High Energy Physics (Theory)
Minimal Proper Time and Deterministic Microstates: Emergent Quantum Fields and Relativistic Spacetime
Alessio Maiezza
We develop a top-down counterpart of the minimal proper-time formulation of
quantum field theory previously introduced as an effective bottom-up framework. Starting from a deterministic pre-
geometric substrate of causally ordered events, we show how coarse-graining over microscopic histories leads, at low energies, to an effective Nambu-like
quantum dynamics. The elementary deterministic update is identified with the minimal proper-time step, while the growth of coarse-grained equivalence classes controls both the ultraviolet dissipative correction and the scale dependence of the effective quantization strength, encoded in a running Planck constant. In this way, the proper-time cutoff kernel of the bottom-up formulation acquires a microscopic interpretation as the inverse growth of unresolved deterministic histories. In the infrared limit, the dissipative term vanishes and standard
unitary quantum field theory is recovered. The same coarse-grained structure also provides a natural setting for an emergent relativistic spacetime geometry, compatible in the macroscopic limit with Einstein
gravity. The resulting picture suggests a common deterministic origin for minimal-scale structure,
quantum behavior, and relativistic spacetime.
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Astrophysics of Galaxies
From Atomic Gas to Star Formation
Erik Rosolowsky, Eric Koch, Sambit Roychowdhury et al. (+9 more)
Since the 2015 SKA Chapters, the advent of panchromatic observations of nearby
galaxies, capable of resolving the interstellar medium (ISM) into individual
star-forming regions and molecular clouds, has revolutionized our understanding of the
star formation cycle in
galaxies. Despite these advances, our understanding of the gas cycle in
galaxies remains limited because we know little about how the cold atomic phase of the ISM, which dominates its mass budget, participates in the cycle. Specifically, the processes regulating the condensation of atomic gas into molecular gas, the balance between warm and cold atomic gas, and their dependence on local environment and
star formation activity have been explored only in the Milky Way and the Magellanic Clouds. The SKA presents a new opportunity to observe the atomic ISM within nearby
galaxies at comparable resolution to other facilities and is the only facility that can make wide-area surveys of atomic gas across a statistical sample of
galaxies at high (<100 pc) spatial resolution. Such observations will directly address the open questions about the
evolution of the
star-forming ISM. We present recent results from SKA-like observations of the Local Group made with SKA pathfinders and the Jansky VLA to illustrate the promise of replicating those observations for hundreds of nearby
galaxies, reaching out to the Virgo cluster.
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All authors Erik Rosolowsky, Eric Koch, Sambit Roychowdhury, Luca Cortese, Filippo M. Maccagni, Barbara Catinella, Nushkia Chamba, Timothy A. Davis, Cosima Eibensteiner, Eric Murphy, Mamta Pandey-Pommier, Amidou Sorgho
Materials Science
Beyond the Parasitic Limit: A Nanoprobing Framework for De-embedding Intrinsic Ferroelectric Properties at the Deep Sub-Micrometer Scale
Niklas Kyoushi, Georg Schönweger, Ole Gronenberg et al. (+4 more)
The continued scaling of ferroelectric devices is critical for next-generation computing architectures, yet it is fundamentally challenged by a metrological bottleneck: at the deep sub-micrometer scale, intrinsic material properties are heavily masked by extrinsic parasitic impedances and
geometric fringing fields. Here, we introduce a quantitative, in-situ nanoprobing framework capable of resolving the true electrical response of ferroelectric capacitors down to 165 nm in diameter without the need for lithographic bond pads. Using 20 nm thick AlScN as a model system, we establish a non-linear 'Screened Power Law' model to decouple attofarad-level device capacitances from massive near-field probe interactions. Furthermore, we demonstrate that the apparent degradation of dielectric loss at the nanoscale is a
geometric dilution artifact, which we overcome through a conductance scaling analysis. Finally, we apply this framework to large-signal characterization, utilizing leakage-compensation and noise filtering protocols to extract pristine intrinsic hysteresis (C-V and J-E) loops in the discrete few-grain limit. These findings provide a universal analytical toolkit required to overcome the measurement limits of deep-submicron ferroelectrics.
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All authors Niklas Kyoushi, Georg Schönweger, Ole Gronenberg, Dirk Meyners, Adrian Petraru, Fabian Lofink, Simon Fichtner
Quantum Physics
Device-independent Quantum Key Distribution in the commuting operator framework
Gereon Koßmann, René Schwonnek, Po-Chieh Liu et al. (+1 more)
Device-independent
quantum key distribution (DIQKD) is arguably the gold standard for secure
quantum communication, as it aims to rely only on observed input-output statistics of an uncharacterized device which is only assumption to obey the laws of
quantum physics. A corresponding security analysis hence demands a description of a
quantum experiment from a most general perspective. Under close inspection, existing proof techniques do not always meet this goal as they tend to rely on subtile assumptions on a tensor product structure of the underlying
Hilbert space and a 'hidden but finite' dimensionality. In this work, we collect the tools needed for a full analysis of DIQKD in the commuting operator framework, which avoids these subtilities and provides the arguably most general view on a
quantum experiment. We rigorously proof the common assumption that in DIQKD measurements can be w.l.o.g. assumed to be projective. Furthermore, we show that task of computing key rates can be casted as a non-commutative
polynomial optimization (NPO) problem to which the Navascués-Pironio-Acín (NPA) hierarchy gives a correct and converging relaxation. As a tool, we generalize the integral representation for the relative
entropy by Frenkel [
Quantum 7, 1102 (2023)] to general von Neumann
algebras and apply techniques from Kossmann and Schwonnek [arXiv: 2411.04858] for the approximation in an NPO program.
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All authors Gereon Koßmann, René Schwonnek, Po-Chieh Liu, Hao-Chung Cheng
Materials Science
Physics adapted generative AI for metal insulator transition materials under label scarcity
Gourab Datta, Sarah Sharif, Zhisheng Shi et al. (+1 more)
Metal-
insulator-transition (MIT) materials are promising candidates for switchable electronics, neuromorphic hardware, and reconfigurable photonics, yet experimentally verified examples remain limited and the underlying mechanisms are often complex. We argue that generative AI for MIT discovery should move beyond the search for stable
crystal structures alone and instead prioritize mechanism-informed phase-transition hypotheses. A modular physics-adapted framework, combined with staged verification of phase competition, electronic contrast, transition-pathway plausibility, and control accessibility, can guide credible discovery under severe label scarcity.
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All authors Gourab Datta, Sarah Sharif, Zhisheng Shi, Yaser Banad
General Relativity and Quantum Cosmology
Generalized Unruh temperature for dynamical thin-shell wormholes
Francisco S. N. Lobo and Manuel E. Rodrigues
We unify two independent notions of effective temperature in dynamical thin-shell wormholes: the local acceleration temperature of the throat and the Hawking-like particle-creation temperature governed by the peeling of null rays. The effective acceleration scale, obtained by averaging over both sides of the junction, defines the thermodynamic shell temperature, while peeling functions for each asymptotic universe yield an effective particle-creation temperature. For asymptotically exponential null-ray maps, we derive the generalized Unruh identity that equates these two temperatures. Applied to Schwarzschild-Schwarzschild wormholes, the formalism yields explicit analytical expressions for the Hawking-like spectra, renormalized
quantum fluxes, and quasi-horizon limits in both symmetric and asymmetric configurations. The divergence of the shell temperature near the quasi-horizon is shown to mirror the divergence of the local Tolman temperature, both originating from the infinite gravitational blueshift at a horizon. These results provide a unified interpretation of acceleration, particle creation, and temperature in horizonless dynamical spacetimes, extending the conceptual link between the Hawking and Unruh effects beyond stationary black holes.
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Instrumentation and Methods for Astrophysics
SGN: A python framework for stream-processing pipelines
Yun-Jing Huang, Olivia Godwin, Chad Hanna et al. (+11 more)
We present the Stream Graph Navigator (SGN), a lightweight Python framework for building streaming data applications. In SGN, stream-processing pipelines are built by connecting computational components into directed acyclic graphs that run within an event loop. The time-series extension of the SGN library, SGN-TS, introduces signal processing methods to handle time series data. Together, SGN and SGN-TS provide the foundation for SGNL, a matched-filtering gravitational-wave search pipeline, and are being adopted by multiple projects across the low-latency gravitational-wave data analysis infrastructure as an extensible and maintainable framework for future gravitational-wave observations.
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All authors Yun-Jing Huang, Olivia Godwin, Chad Hanna, James Kennington, Jameson Rollins, Max Melching, Nathanael E Sovitzky, Aaron Viets, Madeline Wade, Zach Yarbrough, Yu-Kuang Chu, William Wyatt Phillips, Surabhi Sachdev, Rhiannon Udall
Fluid Dynamics
Transferable inference of turbulence models for urban flows with the Parameter-Regularised Ensemble Kalman Filter
Emanuele Bombardi, Andrea Nóvoa, Luca Magri et al. (+1 more)
The accurate simulation of urban flow is key to designing building ventilation, understanding cities' micrometeorology, and predicting pollutant dispersion. Reynolds-Averaged Navier-Stokes (RANS) simulations are a common modelling approach for simulating urban flow, but their accuracy depends on the closure model and its parameters. These parameters are inferred from
benchmark cases, but they are not necessarily suitable for realistic urban environments, which involve different physical mechanisms. This is referred to as the transferability problem of RANS urban modelling. The objective of this work is to propose a robust
Bayesian method to {sequentially} infer RANS parameters for urban flow modelling. Key to the approach is the mathematical derivation of the parameter-regularised ensemble Kalman filter (PR-EnKF), which is the analytical solution of the data assimilation problem for the sequential parameter estimation. The cost functional is regularised using the prior knowledge on the
turbulence parameters, thereby ensuring that the
Bayesian updates remain within physical ranges. The parameters are first inferred on an isolated building, and then transferred to three cases of increasing complexity: (i) a high-rise building, (ii) a multi-building array, and (iii) the Shinjuku district urban environment. Results show that the PR-EnKF achieves faster convergence, reducing parameter uncertainty by an order of magnitude and reconstruction errors by up to 50%. Because of the regularisation, the PR-EnKF selectively updates the most important parameters. This work enables robust large-scale urban flow simulation whilst reducing the computational overhead of model optimisation for urban planning and air quality assessment.
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All authors Emanuele Bombardi, Andrea Nóvoa, Luca Magri, Alessandro Parente
Cosmology and Nongalactic Astrophysics
Hubble tension in k-essence: Evidence for robust tension alleviation
Isaac Opio, Didam Duniya, Bishop Mongwane et al. (+1 more)
The Hubble tension has come to stay as a major problem in modern cosmology as it continues to plague the standard cosmological model ($\Lambda$CDM). As one of the viable, self-consistent dark energy theories, k-essence involves nontrivial self-interactions that can modify the background expansion beyond recombination; thereby impacting the sound horizon to last scattering, and hence, the inferred value of the Hubble constant. We examine this tension in two physically motivated k-essence models, dilaton and tachyon, using
datasets from Planck and late-Universe probes including Pantheon+SH0ES,
cosmic chronometer (CC),
Supernova Cosmology Project Union compilation (Union3), Dark Energy Survey Year~5 (DESY5), and Dark Energy Spectroscopic Instrument (DESI) measurements. While $\Lambda$CDM exhibits inconsistent tension inferences, both k-essence models exhibit a substantial tension alleviation that is robust against the inclusion of the independent late-Universe cosmological
datasets, giving consistent tension reduction irrespective of whether the observations are
supernovae (Pantheon+SH0ES, Union3, DESY5) alone or in combination with
cosmic chronometers (CC) and
baryon acoustic oscillation measurements (DESI). The combined late-Universe
dataset leads to only $0.14\sigma$ and $0.69\sigma$ offsets from the Planck prediction in the dilaton and tachyon models, respectively, compared to $5.89\sigma$ tension in $\Lambda$CDM. Both models demonstrate that the inferred tension alleviation is a stable, intrinsic consequence of the underlying k-essence dynamics rather than of model fine tuning: model parameters remain unchanged across
datasets. The results establish that the apparent Hubble tension is not an unavoidable feature of late-Universe cosmology but depends critically on the description of dark energy.
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All authors Isaac Opio, Didam Duniya, Bishop Mongwane, Hassan Abdalla
Cosmology and Nongalactic Astrophysics
Inflation with nondynamic distortion to leading order in slow roll
Ali Hassan
We study inflation in metric-affine
gravity. We write an action that contains all the second order algebraic distortion terms, and all first order distortion terms with a single covariant derivative, coupled to a scalar field. We include the Einstein–
Hilbert term with nonminimal coupling, a scalar field potential, and impose projective invariance. The distortion equation of motion is algebraic by construction, and the distortion is integrated out analytically. This yields a kinetic term sourced entirely by distortion, with a kinetic coupling function determined by the 13 free coupling constants of the starting action. We compute inflationary observables for three model classes with a monomial distortion coupling. For a monomial potential, the spectral index and tensor-to-scalar ratio depend only on the ratio of the exponents, with the starting coupling constants dropping out entirely; however, this model lies outside the Planck + BK18 $2\sigma$ contours. For a potential of the $\alpha$-attractor form, the observables are governed by a single parameter and approach the Starobinsky predictions as a limit. Including a nonminimal coupling to the
Ricci scalar with a monomial potential can also yield an asymptotically flat effective potential with the same modified Starobinsky observables.
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Optics
Intrinsic Limitations of Single Layer Polychromatic Metalens for Virtual Reality Visors
Myunghoo Lee, Ben Nguyen, Zhihao Zhou et al. (+7 more)
Virtual and augmented reality (VR/AR) visors require compact and lightweight optics. Metalenses have been widely proposed as ultrathin replacements for bulky refractive eyepieces, with performance typically assessed using point spread function (PSF) and modulation transfer function (MTF) measurements. Here, we design, fabricate, and characterize a single-layer silicon nitride metalens optimized for the three emission peaks of an RGB OLED display, and
benchmark it against refractive and Fresnel eyepieces. Under coherent illumination, the metalens exhibits a tightly confined PSF and strong mid-to-high spatial-frequency MTF, suggesting excellent optical performance. However, when evaluated in a realistic system-level VR testbed incorporating incoherent OLED illumination, a dynamic-pupil eye model, and near-eye-relevant focal lengths, the same device exhibits pronounced ghosting and background haze. We show that these artifacts arise from the intrinsic multifocal nature of polychromatic diffractive focusing and demonstrate that common mitigation strategies such as narrowband filtering and long-focal-length relay optics merely mask, rather than resolve, the issue. Our results establish that meta-optics for AR/VR must be evaluated under realistic system-level conditions to reveal their true imaging performance.
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All authors Myunghoo Lee, Ben Nguyen, Zhihao Zhou, Prannav Jayashanker, Shane Colburn, Ethan Tseng, Felix Heide, Praneeth Chakravarthula, Arka Majumdar, Johannes E. Fröch
Optics
Half-wave plasmonic nanolasers near the localization limit
Sangyeon Cho and Seok-Hyun Yun
Miniaturized
lasers with sub-micron dimensions are of broad interest for optical science, on-chip communication, sensing, and biomedical barcoding. Recently, lowest-order half-wave lasing was demonstrated in
semiconductor-on-metal cavities by operating away from the highly dispersive and absorptive surface-plasmon resonance. Here, we demonstrate half-wave-mode lasing near the surface-plasmon resonance at ~630 nm using high-gain indium phosphide (InP) nanoparticles on ultrasmooth gold substrates. The smallest lasing particle, estimated from simulated dispersion curves to have a length of ~115 nm and height of ~100 nm, emitted at 730 nm in air, representing one of the smallest reported active
laser cavities. Linewidth and threshold pump fluence generally decreased as the lasing wavelength shifted farther from the plasmon resonance. In larger particles with lengths of 280~480 nm, we observed lasing attributable to second- and third-order plasmonic modes with progressively narrower linewidths. These results extend half-wave dipolar lasing toward near-infrared and visible wavelengths and further push
laser miniaturization toward the plasmonic localization limit.
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General Relativity and Quantum Cosmology
Black Hole Memory Burden and its Signatures in Gravitational Waves from Mergers
Gia Dvali, Michael Zantedeschi and Sebastian Zell
Swift
memory burden (MB) implies that the information stored in a black hole (BH) can modify its classical dynamics when the BH is perturbed. This influences the gravitational waves (GWs) emitted during BH mergers. In this paper, we investigate how the BH
memory load is determined by the features of the collapsing source. We show that the
memory load can vastly exceed the information content of its progenitor. An extreme example is a BH formed in a two-particle collision, which exhibits maximal MB. We then derive bounds for BHs formed through
stellar collapse and examine the impact of swift MB on BH quasinormal modes, quantifying the MB-induced frequency shift of GWs. These findings imply that GW observations probe the fundamental mechanisms of BH information storage as well as their formation history.
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High Energy Astrophysical Phenomena
Lucas M. Pasquevich, Gustavo E. Romero and Matías M. Reynoso
Multimessenger observations suggest that Seyfert
galaxies are promising sources of high-energy
neutrinos, but their dense inner environments can strongly suppress the emerging very-high-energy gamma-ray emission. Active
galactic nuclei (AGN) undergoing intense
accretion episodes can enter a super-Eddington state, in which the
accretion flow becomes geometrically and optically thick within a critical radius and develops strong
magnetic fields in its innermost region. At the same time, large amounts of matter are expelled from the disk surface in the form of powerful, radiation-driven winds. In this work, we explore a scenario in which the cores of super-Eddington AGN provide suitable conditions for the acceleration of relativistic particles, including
hadrons, via
magnetic reconnection in a magnetically confined region close to the supermassive black hole. The accelerated hadronic component interacts with the intense
photon field of the disk, leading to a copious
neutrino flux peaking at 10-100 TeV that may be detectable with current observatories such as IceCube and KM3NeT, while the surrounding
outflow efficiently absorbs the accompanying gamma-ray emission from the inner core. We also apply the model to the nearby super-Eddington Seyfert 1 NGC 7469 as a representative case with two reported
neutrino events. In this framework, super-Eddington AGN, in particular Seyfert
galaxies undergoing transient intense
accretion episodes, emerge as plausible hidden
neutrino sources, offering a natural explanation for the coexistence of efficient
neutrino production and a strongly attenuated gamma-ray counterpart.
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Exactly Solvable and Integrable Systems
Maximal Densities of Finite-Gap Solutions of the Sine-Gordon Equation
Otis C. Wright III
We establish a sharp upper bound on the densities of finite-gap solutions of the sine-Gordon equation. The bound is derived directly from the finite-dimensional hierarchy, without explicit integration of the finite-gap solutions. The maximal density is determined by the roots of the invariant
polynomial. An analogous sharp upper bound is established for a bounded class of finite-gap solutions of the sinh-Gordon equation.
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Quantum Physics
A Pulsed Live-Cell Quantum Microscope for Entangled Solid State and Biological Qubits
Javier Noé Ramos-Silva, Sangjun Noh, Minghao Jiang et al. (+5 more)
Two revolutions in
quantum sensing are converging on the same microscope stage. Biological
qubits have emerged as genetically encoded, optically addressable
quantum systems inside live
cells. Solid state
spin based
qubits have been entangled and used as nanoscale correlator magnetometers, delivering sensitivity and spatial-resolution gains that single-
spin probes cannot reach. Here we report a pulsed
quantum microscope that enables simultaneous
quantum state manipulation of both
qubit technologies in live
cells. The platform combines nanosecond-gated optical excitation at 450 nm and 520 nm, three-dimensional diffraction-limited addressing by galvo beam scanning and piezo objective focus, rapidly switched static and
radio-frequency
magnetic fields, single-
photon timing with picosecond resolution, and microwave control for frequencies from DC to 5 GHz, including the 2.87 GHz resonance of solid state
spins, the 500 MHz to 800 MHz resonance of radical pairs in biological
qubits, and any future
qubit resonance in the GHz range. Live
cell imaging with simultaneous biological and solid state nanoparticle
qubits in the same
cell demonstrates the power of this technique for multiplexed
quantum sensing. We anticipate this approach will open new opportunities for researchers to explore
quantum sensing in live
cells, and, ultimately,
entanglement between a solid-state
qubit and a
protein-hosted
spin qubit.
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All authors Javier Noé Ramos-Silva, Sangjun Noh, Minghao Jiang, Parisa Aghaei, Ayla Hazrathosseini, Jocelyn Leon, Philip Hemmer, Peter J. Burke
Chemical Physics
Intrinsic Matching Frustration in Fluctuating Finite Systems
Leonid Rubinovich and Micha Polak
We formulate intrinsic matching frustration (IMF), a fluctuation-induced, kinetics-independent reduction in the mean capacity permitted by a prescribed matching rule. For complementary one-to-one matching, the instantaneous capacity is set by the minority population, so fluctuations produce a nonzero mean deficit even when the two populations are balanced on average. At finite size, this deficit depends on the full distribution of the population difference and is determined by its variance alone only in the Gaussian limit. Compartmentalization hides matching capacity by preventing cancellation between local imbalances of opposite sign. Fusion releases this hidden capacity monotonically under coarse graining, producing a measurable recovery of product yield following local reaction to completion.
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High Energy Astrophysical Phenomena
Beyond the Impulsive Approximation: The Dynamics and Radio Emission of Tidal Disruption Jets
Fabio De Colle and Enrico Ramirez-Ruiz
Radio emission from relativistic
tidal disruption events (TDEs) is commonly interpreted using the Blandford–McKee solution for an impulsive relativistic blast wave. Unlike gamma-ray bursts, however, TDE jets are powered by fallback
accretion, injecting energy over weeks to months. We investigate how this sustained energy injection modifies the dynamics and
radio emission of relativistic TDE jets using one- and two-dimensional relativistic hydrodynamic simulations coupled with synchrotron radiation calculations. For a fixed total energy, fallback-powered jets drive slower forward shocks, producing delayed and systematically fainter
radio emission. We show that the impulsive approximation is valid only when the duration of energy injection is less than approximately ten percent of the deceleration time of an equivalent Blandford–McKee blast wave, a condition that is generally not satisfied for relativistic TDEs. As a result, continuously powered
outflows are significantly less beamed than impulsive explosions, leading to a strong suppression of off-axis
radio emission. These results demonstrate that the
radio evolution of relativistic TDEs retains
memory of the central engine and cannot, in general, be described by an impulsive solution. By substantially reducing the expected off-axis
radio emission, sustained fallback-powered jets imply that relativistic jet production in
tidal disruption events may be considerably more common than current
radio observations suggest.
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High Energy Physics (Phenomenology)
Spontaneous CP breaking in $S_3$ flavored Higgs sector with soft-breaking terms
E. Barradas-Guevara, O. Félix-Beltrán, A. Pérez Martínez et al. (+2 more)
We analyze the
Higgs sector of the minimal $S_3$-invariant extension of the Standard Model including spontaneous and explicit CP violation arising from the spontaneous electroweak
symmetry breaking. This extended
Higgs sector includes three SU(2)
Higgs doublets with and without complex vev's, which ones providing an interesting scenario to analyze the
Higgs masses spectrum, trilinear
Higgs self-couplings and CP violation. We present how the spontaneous electroweak
symmetry breaking coming from three SU(2)
Higgs doublets gives an interesting scenario when spontaneous CP violation arises from the
Higgs doublet $\Phi_S$, singlet under $S_3$. Furthermore, a numerical analysis of the
Higgs masses and trilinear
Higgs self-couplings is presented. Particularly, we find a physical solution for the scenario in which spontaneous CP break is provided by $\Phi_S$. The analysis of soft breaking to $S_3$
symmetry including CP breaking terms opens up a rich parameter space, with
Higgs masses and trilinear
Higgs self-couplings favoring one of the
Higgs bosons as a SM-like type
Higgs boson.
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All authors E. Barradas-Guevara, O. Félix-Beltrán, A. Pérez Martínez, E. Rodríguez-Jáuregui, J. Montaño-Peraza
Mathematical Physics
Anomalous rate of eigenstate thermalisation at singularities of the density of states
László Erdős, Joscha Henheik and Volodymyr Riabov
We prove the Eigenstate Thermalisation Hypothesis (ETH), also known as
Quantum Unique Ergodicity (QUE), for large $N\times N$ mean-field random
matrices with general correlation structure. We identify the microcanonical ensemble and establish the optimal fluctuation scale of eigenvector overlaps around it. Our results invalidate the inverse-density scaling predicted by Feingold and Peres [Phys. Rev. A 34, 591 (1986)] (and incorporated into Srednicki's ansatz [Phys. Rev. E 50, 888-901 (1994)]) in the physics literature of
quantum chaos, based upon popular semiclassical theory, and uncover the genuine mechanism which relies on multi-resolvent local laws. Although fluctuations are expected to increase as the density of states vanishes, and indeed scale as $N^{-1/2}$ in the special cusp regime, rather than $N^{-1}$ in the bulk, we find, unexpectedly, that the same $N^{-1}$ rate persists at regular spectral edges. Hence, generically, in the absence of cusps, the entire eigenbasis fluctuates on the same scale as a Haar
unitary. This anomaly stems from delicate cancellations in the solution of the underlying
matrix Dyson equation, which form the core of our analysis.
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Disordered Systems and Neural Networks · Cross-listed from q-bio.MN
Cellular Adaptation to Signal Fluctuations as Learning
Tuan Minh Pham and David Saad
Cells represent one of the most fundamental units of life. Underlying their robust performance against environmental variability, such as temporal fluctuations of chemical signals, between different
cell types, is a dynamical interrelation between the two components of an intracellular pathway: a gene-regulatory network and its upstream signal transducers. To understand how a single
cell utilizes this feedback to self-regulate its gene-expressions, we develop a multiscale model of the pathway's components, in which the adaptive variables responsible for signal interpretation follow a feedback-induced learning process. We then derive a macroscopic theory capturing the covariations between these components - so-called collective modes. Our theory shows how
cells can achieve robust output against signal fluctuations via self-regulation rather than simple noise suppression. Such robustness corresponds to a transition from random- to structured collective modes beyond a critical adaptation rate.
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Mesoscale and Nanoscale Physics
Nonlocal Orbital-Angular-Momentum Dichroism of Vortex Light in Strained Crystals
Habib Rostami
Vortex light carries orbital angular momentum (OAM) in its transverse phase. We show that the transverse phase cannot generate OAM-odd absorption in any continuously translation-invariant system, even when optical nonlocality and multipole light–matter coupling are included. The combination of broken continuous translation
symmetry and finite-range optical nonlocality permits OAM dichroism through transverse-momentum mixing; in nonuniformly strained Dirac materials, the dichroism factorizes into a nonlocal elasto-optic tensor and the overlap of the strain texture with the
vortex transverse phase current.
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Astrophysics of Galaxies
A MIGHTEE robust measurement of the star formation rate-radio correlation
Charlotte L. Jackson, Matt J. Jarvis, Imogen H. Whittam et al. (+9 more)
Determining the relationship between
star-formation rate (SFR) and the
radio luminosity ($L_{1.4}$) is critical if we are to trace the
star-formation history of the Universe
dust-agnostically using current and future
radio facilities. However, until now, such work has relied on potentially biased binary classifications of sources to remove contaminating active
galactic nuclei (AGN). We present a new, statistically-driven methodology for deriving the SFR – $L_{1.4}$ relation, removing the need for problematic cuts. We use a
Bayesian hierarchical mixture model fit to the
radio-detected sources in the deep MIGHTEE COSMOS DR1 catalogue, incorporating the full SFR posterior probability distributions generated by state-of-the-art spectral energy distribution fitting code GRAHSP. This allows us to probabilistically determine a mean SFR – $L_{1.4}$ relation for the SF dominated
galaxies, whilst accounting for changing fractions of SF dominated sources across
redshift,
radio luminosity and
stellar mass ranges. We find that the SFR –
radio luminosity correlation exhibits a significant dependence on
redshift, but a
stellar mass dependence that is weaker than previous studies. Our resultant SFR-
radio correlation is $\log_{10}(\text{SFR}/M_{\odot}\,\text{yr}^{-1}) = 0.790\times(\log _{10}(L_{1.4}/\text{WHz}^{-1})-23) + 1.244 \times(1+z)^{0.122} -0.033 \times (\log_{10}(M_*/M_{\odot})-10)$, with an intrinsic scatter of 0.178 dex. We show that this
redshift evolution could be explained by a moderate
evolution in the
radio spectral index of SF
galaxies. We attribute the lack of observed strong dependence on
stellar mass, compared to recent studies, to the novel statistical approach that does not rely on cuts to remove AGN.
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All authors Charlotte L. Jackson, Matt J. Jarvis, Imogen H. Whittam, James H. Matthews, Johannes Buchner, Catherine L. Hale, Joel Hamlett, S. Lyla Jung, Mara Salvato, Daniel J. B. Smith, Natalia Stylianou, Rohan G. Varadaraj
High Energy Astrophysical Phenomena
Multiwavelength properties of short gamma ray bursts with extended emission observed by Swift
M.M. Dinatolo, A. Mei, R. Brivio et al. (+11 more)
Short gamma-ray bursts with extended emission (SGRBEEs) are a particular class of long GRBs (LGRBs) which, despite their duration, share several observational features with short GRBs (SGRBs). They are composed by a short, hard initial pulse (IP) followed by a longer and softer extended emission (EE). We investigate whether SGRBEEs originate from the same progenitor as SGRBs despite their duration, representing a peculiar subclass of LGRBs, or if they constitute a distinct population. Given their respective duration, we tested if the IP and the EE share properties with short and long GRBs, respectively. We analysed SGRBEEs from the flux-limited,
redshift-complete SBAT4 sample using
prompt-emission data from Swift/BAT,
Fermi/GBM and Konus-WIND, and X-ray afterglow observations from Swift/XRT. The temporal and spectral properties of the IP and EE components were compared with those of SGRBs from the extended SBAT4 sample and LGRBs from the BAT6 sample. Despite observing a clear spectral
evolution during the
prompt phase of each SGRBEE, IPs and EEs as well as short and long GRBs can not be distinguished by their hardness ratio only. All bursts analysed have a spectral lag consistent with zero. SGRBEEs XRT light curves are consistently more complex than those of SGRBs, requiring the addition of multiple breaks and showing the presence of steep decays and plateaus. Our results indicate that SGRBEEs are not an intermediate class. During
prompt emission, despite common spectral features, IPs and EEs temporally differ from short and long GRBs, respectively. EEs are on average too faint to appear in the Amati plane, but IPs occupy the same parameter space of SGRBs. In the afterglow, SGRBEEs are more luminous than standard GRBs at early-time, suggesting a direct contribution from the EE; at later times, these events behave as standard SGRBs, and both remain systematically less luminous than LGRBs.
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All authors M.M. Dinatolo, A. Mei, R. Brivio, M. Ferro, M.G. Bernardini, P. D'Avanzo, S. Belova, S. Campana, S. Covino, D. Frederiks, B. Haskell, R. Salvaterra, B. Sbarufatti, A. Tsvetkova
Quantum Physics
The arrival position problem in quantum mechanics
Ali Ayatollah Rafsanjani and Will Cavendish
The problem of making unambiguous probabilistic predictions about experiments involving waiting "always on" detectors remains a challenge for
quantum theory. While most research on this problem studies arrival time, i.e., predicting the distribution of when detection events occur, this paper studies the arrival position problem, which is the complementary challenge of predicting the distribution of where detection events occur. Despite the widespread recognition of the arrival time problem, the inability of standard
quantum theory to address the arrival position problem remains a pervasive theoretical blind spot. In this paper, we compare quantitative arrival position predictions derived from prominent proposed solutions to the screen problem. As we show, these models yield distinguishable predictions even in relatively simple experiments achievable with current technology. Notably, many of these discrepancies persist even in the far-field limit, where standard semiclassical approximations are typically assumed to be valid.
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High Energy Physics (Phenomenology)
Gravitational Wave Signatures of Cosmological Stasis: A Unified Spectral Template
Gabriela Barenboim and Anne-Katherine Burns
Proposed in 2022 by Dienes et al., stasis is a dynamical fixed point in the early universe in which the equation of state, $w_s$, is fixed at a constant value. In this study we show that the inflationary gravitational wave imprint of any stasis epoch is captured by a closed-form spectral template controlled by two physical inputs, the equation of state $w_s$ and the stasis duration $\Delta N_\mathrm{stasis}$, that applies uniformly across every microphysical realization. The template presented here yields two independently measurable observables, the spectral tilt of the spectra in the stasis band, $\alpha(w_s)$ and the amplitude step $C^2(w_s)$ at the beginning and end of the stasis band. Eliminating $w_s$ gives a one-parameter consistency curve $C^2 = C^2(\alpha)$ on which the data must lie if the underlying cosmology is any constant-$w$ era. This makes the spectrum falsifiable without knowing $w_s$ in advance: a measured $(\alpha, C^2)$ pair either lands on the curve or rules out the constant-$w$ class. We show that BBO and DECIGO can resolve the perpendicular displacement from the consistency curve to $\sigma_\perp \simeq 1.5\times10^{-5}$ at a tensor-to-scalar ratio, $r = 0.01$, four orders of magnitude below the curve's range in $C^2$ meaning that any off-curve deviation is detectable across a broad range of allowed $r$ values.
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Astrophysics of Galaxies
Pebbles to Gems: Intermediate-mass black holes in the first star clusters
Benedetta Mestichelli, Manuel Arca Sedda, Marta Volonteri et al. (+9 more)
The rapid assembly of supermassive black holes (SMBHs) observed at $z\gtrsim7$ requires efficient seeding mechanisms in the early Universe. Population III (Pop. III)
star clusters have recently emerged as a promising pathway that may bridge the gap between traditional light- and heavy-seed scenarios by producing intermediate-mass black holes (IMBHs) with masses up to $\sim10^4\,\rm M_{\odot}$. We investigate the properties and number densities of IMBHs forming in Pop. III
star clusters with masses $M_{\rm cl}\sim10^3-4\times10^5\,\rm M_{\odot}$, and hosted in isolated dark matter minihalos, using a suite of direct $N$-body simulations. We adopt cosmologically motivated initial conditions and explore different
stellar evolution prescriptions, binary orbital parameter distributions, and cluster dynamical configurations. By $z\sim19$, the IMBH mass function consistently peaks at $m_{\rm IMBH}\sim200\,\rm M_{\odot}$, with number densities of $n_{\rm IMBH}\sim0.2-5\,\rm cMpc^{-3}$. In sufficiently dense and massive clusters, IMBHs with masses $>10^3\,\rm M_{\odot}$ can already form by $z\sim19$, reaching number densities of $n_{\rm IMBH}\sim10^{-4}-10^{-2}\,\rm cMpc^{-3}$. The most massive IMBHs in our models reach $\sim6200\,\rm M_{\odot}$ through the collapse of very massive
stars assembled by repeated
stellar collisions, a process enhanced in fractal clusters. Lower-mass IMBHs form instead predominantly through single and binary
stellar evolution and binary
stellar mergers. We find that models combining large
stellar radii and tight binaries produce the highest IMBH abundances relative to isolated Pop. III
evolution. Owing to the high retention fraction of IMBHs ($\gtrsim88\%$), massive dense Pop. III
star clusters can act as efficient incubators of both light and heavy SMBH seeds, even if only a fraction of Pop. III
stars formed in such environments.
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All authors Benedetta Mestichelli, Manuel Arca Sedda, Marta Volonteri, Michela Mapelli, Stefano Torniamenti, Alessandro Lupi, Marica Branchesi, Shingo Hirano, Tomoaki Ishiyama, Ralf S. Klessen, Veronika Lipatova, Boyuan Liu