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Physics

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Tuesday 7 July

High Energy Physics (Phenomenology)

Particle Cosmology: 1980-2000

Edward W. Kolb

A new field, Particle Cosmology, emerged at the interface of elementary particle physics and cosmology in the last two decades of the 20th century. In this chapter of the Proceedings of the 4th International Symposium on the History of Particle Physics, the Standard Model and Beyond I will review the development of Particle Cosmology in the period 1980-2000 centered on two events: a conference, Inner-Space/Outer-Space held at Fermilab in May 1984 \cite{kolb1986innerspace} and the 1994 Snowmass Summer Study Particle and Nuclear Astrophysics in the Next Millennium \cite{kolb1995particle}.
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Applied Physics

Soft cells, Tubular Tilings and the Hidden Phases in Binary Mixtures

Gábor Domokos

Biological and physical systems ranging from Fermi surfaces and skeletal structures to reaction–diffusion patterns and cosmological models may be viewed as binary mixtures in which a smooth interface separates two complementary phases. While the interface is often directly observable, the topology of one of the phases may remain hidden. To study such systems, we introduce tubular tilings, a geometric framework for discretizing binary mixtures on smooth manifolds of arbitrary dimension and topology. We prove that tubular tilings satisfy global Euler balance laws relating the topology of the ambient manifold, the discretized phases, and their interfaces. These balance laws provide a practical inference principle: topological information about a hidden phase can be recovered from the observable phase and the geometry of the separating interface. We further show that, in dimensions $d>2$, tubular tilings form a subclass of soft tilings, the recently discovered class of corner-free tessellations. Applications to Fermi surfaces and cosmological shell decompositions illustrate how the theory can be used to extract otherwise inaccessible topological information about complex geometric structures.
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Instrumentation and Methods for Astrophysics

"Perfect" spectra for ESO's HARPS spectrograph

Dinko Milaković, Guido Cupani, Bruce A. Bassett et al. (+2 more)

HARPERFECT is the first application of "spectral perfectionism" to a high-resolution echelle spectrograph, reconstructing 1D spectra from 2D detector data via a forward model built on a calibration matrix consisting of point-spread function (PSF) shape, wavelength, and order trace, which were built entirely from laser frequency comb (LFC) observations. HARPS cannot resolve individual LFC lines, so each of 21 148 identified lines directly samples the PSF. We modelled these with a bivariate Gaussian, determining the PSF shape on the detector, calibrating wavelength, and tracing orders more accurately than the standard HARPS pipeline. Applied to 52.5 hours of HARPS data on quasar HE0515-4414, HARPERFECT gives S/N comparable to, though slightly lower than, the standard pipeline. Its value lies in an exact resolution matrix and independent samples, properties standard extraction cannot guarantee for a non-separable PSF - a step toward better measurements of fundamental constants and exoplanet atmospheres.
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All authors Dinko Milaković, Guido Cupani, Bruce A. Bassett, Stefano Cristiani, Luca Pasquini

Physics and Society

Will AstroForge Collapse the PGM Market?

Robert T. Nachtrieb and Steven J. Smith

AstroForge seeks to mine platinum group metals (PGM) from asteroids. Asteroid reserves appear to be unlimited, and at current market price the gross margin of asteroid mining would be very high. It is natural to ask: when AstroForge successfully demonstrates economic space mining of PGM, will they cause the PGM market to collapse? We answer the question with a non-steady system dynamics model of the PGM market. We find that the market price for PGM will eventually drop towards the much lower cost of asteroid mining, but only after the entire supply has shifted off-world. In the meanwhile, huge fortunes will be made. And everybody on Earth will benefit from new applications of lower-price PGM.
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Physics and Society

Unified Framework for Binary-Choice Dynamics: Analysis and Applications

Arkadiusz Jędrzejewski and José F. F. Mendes

We demonstrate how the unified framework for binary-choice dynamics can be used to study the role of annealed and quenched disorders in homogeneous and heterogeneous systems. The framework defines the structure of interactions between agents without imposing their functional forms. Such a high level of generality allows us to connect many different models across disciplines and find universal rules that apply to all of them. Within this framework, agents update their states under the influence of two competing mechanisms chosen according to individual preferences. We review the literature to classify existing models as homogeneous or heterogeneous based on their preference distribution, and we discuss the role of annealed (changing) and quenched (fixed) disorders in modeling these preferences. Using the framework, we derive a constraint on the transition rates. When a model meets this condition, three major things happen: annealed and quenched dynamics become equivalent, any heterogeneous system can be mapped into a homogeneous one, and oscillations cannot emerge. We illustrate these consequences using models from statistical physics, opinion dynamics, and disease spreading. Finally, we discuss the framework limitations and its potential further developments.
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Mathematical Physics

On the Geometrical and Kinematical Foundations of the Symmetric Relativity Model: Lorentz Transformation and Time Dilation

Miodrag Mateljević

We examine the kinematic foundations of relativity by considering two inertial frames, $S$ and $S'$, in a standard configuration, where $S'$ moves along the common spatial $x$-axis at a constant velocity $v$. By relaxing Einstein's second postulate regarding the universal invariance of the one-way speed of light, we adopt an operational framework grounded strictly on the directly observable two-way (round-trip) speed of light, evaluated alongside the principles of spacetime homogeneity, linearity, and reciprocity. Within this setting, we demonstrate that: (i) the classical Lorentz transformation is recovered exactly along the coordinate axes under a generalized two-way synchronization scheme without requiring Einstein's second postulate; (ii) Langevin's light-clock argument fundamentally implies that the longitudinal scale factor $b$ matches the standard Lorentz factor $\gamma$; and (iii) transverse lengths remain strictly invariant ($b_z = 1$). Crucially, to resolve the ontic paradox of multiple co-existing wavefront centers, we introduce a kinematically symmetric model relative to an absolute cosmological rest frame (or geometric anchor) $K$, wherein $S$ and $S'$ move with equal and opposite velocities ($u$ and $-u$, respectively). Within this generalized framework, allowing for anisotropic one-way light propagation via Reichenbach-type parameters ($\varepsilon$ or $\kappa$) yields a consistent, linear velocity-addition law, a generalized Doppler effect, and a flat but oblique spacetime metric. Finally, we prove that all round-trip observables remain strictly invariant under synchronization gauge transformations (reflecting the Tangherlini-Edwards perspective) and demonstrate that the resulting non-diagonal metric structure is fully consistent withthe Sagnac effect over closed spatial loops.
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Soft Condensed Matter

Evaporation-Driven Nanowire Self-Assembly in an Elongated Droplet

Johannes Schöttner, Qingguang Xie and Jens Harting

Drying of nanowire-laden elongated droplets is a ubiquitous process in printed electronics fabrication, where the resulting deposition pattern critically determines device performance by controlling nanowire alignment, connectivity, and percolating charge-transport pathways. However, the physical understanding of evaporation-driven deposition is still largely derived from studies of spherical droplets on homogeneous substrates. This gap limits the ability to predict and control deposit morphology in realistic printing scenarios. Here, we use mesoscale lattice Boltzmann simulations to investigate the drying of nanowire-laden elongated droplets on wettability-patterned substrates, focusing on the effects of droplet geometry, nanowire interactions, and nanowire length. The elongated droplet geometry is found to intrinsically induce distinct axial and transverse inhomogeneities in the final deposit. Increasing the effective attraction between nanowires, which mimics changes in surface chemistry or solvent conditions, can improve electrical connectivity but also promotes clustering and local ordering, reducing structural uniformity. In contrast, increasing nanowire length yields a dual benefit by improving long-range connectivity while simultaneously enhancing deposit homogeneity. Our findings provide design guidance for balancing electrical transport and structural uniformity in evaporation-driven printed electronics.
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Nuclear Experiment

Measurements of $\gamma_v p \to \pi^+ \pi^- p'$ Cross Sections with the CLAS Detector for $Q^{2}$ from 2.0–5.0~GeV$^{2}$ and $W$ from 1.400–2.125~GeV

A. Trivedi, R.W. Gothe, E. Phelps et al. (+108 more)

Observables in the electroproduction of the $\pi^+\pi^-p$ reaction channel off the proton that are sensitive to the polarization of the virtual photon are presented for the first time in addition to the extraction of the nine single-differential and fully integrated cross sections within the kinematics area of 2.0~GeV$^2 < Q^2 < 5.0$~GeV$^2$ and 1.400~GeV $< W < 2.125$~GeV measured with the CLAS detector in Hall B at Jefferson Lab. The extraction of the unpolarized cross sections has been considerably improved in comparison with previously published results from this same dataset, offering finer binning over the five-dimensional hadronic reaction phase space, and including essential advances in the acceptance evaluation by implementing a new technique to stabilize the cross section extraction and minimize the systematic uncertainty associated with the simulation statistics. These improvements are of particular importance for the extraction of the $\gamma_v p N^*$ electrocouplings from these data.
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All authors A. Trivedi, R.W. Gothe, E. Phelps, V.I. Mokeev, D.S. Carman, P. Achenbach, J. S. Alvarado, M.J. Amaryan, N.A. Baltzell, L. Barion, F. Benmokhtar, A. Bianconi, A.S. Biselli, M. Bondi, F. Bossu, K.-Th. Brinkmann, W.J. Briscoe, J. Bryce, T. Cao, P. Chatagnon, H. Chinchay, G. Ciullo, E.W. Cline, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, A. Deur, S. Diehl, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, M. Farooq, S. Fegan, I.P. Fernando, E. Ferrand, A. Filippi, K. Gates, D.I. Glazier, B. Gualtieri, H. Hakobyan, T.B. Hayward, D. Heddle, M. Hoballah, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, M. Khandaker, F.J. Klein, V. Klimenko, A. Kripko, V. Kubarovsky, C. Lama, L. Lanza, P. Lenisa, X. Li, D. Martiryan, V. Mascagna, A. Mehta, M. Mirazita, E.F. Molina Cardenas, C. Munoz Camacho, P. Nadel-Turonski, T. Nagorna, K. Neupane, S. Niccolai, G. Niculescu, M. Osipenko, A. Osmond, P. Pandey, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, C. Paudel, S.J. Paul, W. Phelps, L. Polizzi, Y. Prok, A. Radic, M. Ripani, M. Ronayette, A.A. Rusova, S. Schadmand, A. Schmidt, R.A. Schumacher, S. Shrestha, E. Sidoretti, N. Sparveris, S. Stepanyan, I.I. Strakovsky, S. Strauch, M. Tenorio, F. Touchte Codjo, R. Tyson, M. Ungaro, S. Vallarino, C. Velasquez, L. Venturelli, H. Voskanyan, E. Voutier, Y. Wang, U. Weerasinghe, X. Wei, L. Xu, Z. Xu, Z.W. Zhao, V. Ziegler

Materials Science

Symmetry-Enforced Chiral Phonons in Altermagnets via Magnon-Phonon Coupling

Philipp Rieger, Markus Weißenhofer, Sergiy Mankovsky et al. (+1 more)

Chiral phonons are attractive for spintronics applications, however, their zero-field generation in conventional antiferromagnets is forbidden by combined parity and time-reversal ($\mathcal{PT}$) symmetry. Here we demonstrate the emergence of chiral phonons in $\mathcal{PT}$-breaking altermagnetic systems at zero field arising from relativistic magnon-phonon coupling. Focusing on the prototypical altermagnet CrSb, we utilize first-principles methods to calculate the hybridized magnon-polarons across the complete Brillouin zone. We show that this coupling imprints an altermagnetic $g$-wave symmetry directly onto the phonon angular momentum. Furthermore, we demonstrate anomalous spin and phonon angular momentum Nernst responses arising from finite Berry curvatures. These findings establish that chiral lattice dynamics can arise in compensated magnetic ground states without requiring external fields, positioning bulk altermagnets as material candidates for zero-field spin caloritronics and chiral phononics.
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All authors Philipp Rieger, Markus Weißenhofer, Sergiy Mankovsky, Peter M. Oppeneer

Atomic Physics

Microsecond-Scale Coherent Control of a Forbidden Clock Transition with Doppler-Free Multiphoton Excitations

Guglielmo Panelli, Erik J. Porter, V. Rose Knight et al. (+2 more)

We demonstrate two Doppler-free (DF) excitation schemes for coherent manipulation of the ${}^1\!S_0 - {}^3\!P_0$ clock transition in $^{88}$Sr that achieve microsecond-scale excitation times. The first approach uses three-photon excitation with distinct phase-coherent spectral components to couple the ground and clock states while canceling the first-order Doppler shift. The second approach is a sequential protocol that combines a single-photon excitation with a two-photon Raman excitation, reducing coherent clock transition manipulation times to below a microsecond. With both methods, we perform high-contrast Ramsey spectroscopy on thermal ensembles of $3 \times 10^{6}$ atoms in free space. We observe three orders of magnitude suppression of Doppler dephasing compared to single-photon excitation, relaxing the need for tight confinement or ultra-low temperatures. These broadly applicable techniques enable fast, coherent manipulation of narrow-line transitions, with implications for optical atomic clocks, matter-wave interferometers, quantum-enhanced metrology, and quantum information processing.
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All authors Guglielmo Panelli, Erik J. Porter, V. Rose Knight, Shaun C. Burd, Mark Kasevich

Statistical Mechanics

Microscopic Dynamical Entropy I: Quantifying Hamiltonian Irreversibility in Large and Small Systems

Mingnan Ding and Michael E. Cates

We introduce a Microscopic Dynamical Entropy (MDE) for Hamiltonian systems, defined with respect to a chosen partition of degrees of freedom into a system X and its environment Y. The construction is based on the conditional phase-space volume (CPV), or conditional Boltzmann entropy, associated with the unmonitored degrees of freedom Y. The MDE is a microscopically defined entropy functional of the marginal distribution $\rho_X(t)$, obtained by discarding conditional microscopic information associated with Y from the Gibbs entropy of the joint XY system, while retaining exact Hamiltonian dynamics. This construction clarifies the microscopic origin of thermal entropy. The dependence of MDE solely on $\rho_X(t)$ is consistent with the thermodynamic assumption that the entropy increment of a heat bath Y depends on its heat content and temperature, not on details of its probability distribution. Indeed, the MDE recovers dS = dQ/T connecting entropy increments to heat flow between system and environment. More generally, it provides a consistent description of irreversible relaxation under exact Hamiltonian dynamics, while permitting transient entropy decreases in small systems and in spin-echo type protocols. Under time-scale separation between X and Y, the MDE becomes strictly monotonic in time, recovering the familiar structure of irreversible thermodynamics. The MDE can foreshadow thermodynamics even in a small isolated Hamiltonian system, if X is a well chosen subset of its degrees of freedom. An example is the centre of mass of interacting particles confined to a box. Even for as few as N=10 particles, the MDE increases during relaxation towards a maximum at equilibrium, with increasing monotonicity at larger N. Taken together, our results show that the MDE offers a microscopic interpretation of nonequilibrium thermal entropy and its time dependence within exact Hamiltonian dynamics.
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Quantum Physics

Secret Key Rate Analysis of Distribution Matching Algorithms for Discrete-Modulated CV-QKD

Micael Dias, Caroline Alves, Gabrielly Roman et al. (+1 more)

Continuous variable quantum key distribution protocols (CV-QKD) with discrete modulation have been intensively investigated to bridge the gap between ideal Gaussian modulation and modern coherent optical communication systems. To mitigate the penalty of discrete modulation, probabilistic constellation shaping (PCS) is applied to the modulation format and is typically performed by distribution matching (DM) algorithms. In this paper, we address the application of DM algorithms to perform PCS in CV-QKD protocols. We investigate the impact of approximating optimized Maxwell-Boltzman distributions with DM algorithms based on Huffman (HDM) and constant composition (CCDM) codes on the protocol's secret key rate (SKR) and tolerance to excess noise. Our results show that specifically symbol-by-symbol HDM degrades the SKR by at least 30%, whereas CCDM matches the optimal SKR with code length of $10^3$ or more symbols. Furthermore, we also provide a statistical analysis of symbol dependence for both approaches, showing that CCDM must operate with blocks of at least $10^5$ symbols for the correlations become negligible. Finally, we propose an algorithm to generate independent symbols following near-optimal distributions.
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All authors Micael Dias, Caroline Alves, Gabrielly Roman, Søren Forchhammer

Chemical Physics

Hydrogen-Bond Donor-Acceptor Imbalance in Low-Frequency Terahertz Water Spectra

Lilian Najm Alsayed, Florian Pabst, Giuseppe Cassone et al. (+2 more)

The low-frequency dielectric response of liquid water is commonly described by a dominant Debye relaxation together with additional faster contributions whose microscopic origin remains debated. Here we show that the dielectric function of water between 0.14 and 1.21 THz can be represented by a collective Debye relaxation plus a Drude-Smith term constrained to the zero-dc-conductivity limit. The Drude-Smith spectral weight increases upon heating pure H2O from 20 C to 50 C and decreases upon isotopic substitution (D2O at 20 C vs. H2O at 20 C). Molecular dynamics simulations including nuclear quantum effects show correlated changes in the population of water molecules with unequal numbers of donated and accepted hydrogen-bonds. Ab-initio-based spectra calculations further indicate that the ~0.1-1 THz response contains both nuclear-motion and explicit electronic-polarisation/charge-redistribution contributions. We therefore interpret the excess low-frequency THz response as a localised, mixed nuclear-electronic dielectric response correlated with transient donor-acceptor imbalance in the hydrogen-bond network.
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All authors Lilian Najm Alsayed, Florian Pabst, Giuseppe Cassone, Ali Hassanali, Fabio Novelli

High Energy Astrophysical Phenomena

Radio Observations of the Unusual Tidal Disruption Event AT 2022wtn: a Fast and Highly Energetic Outflow

Gavin Farley, Tanmoy Laskar, Noah Franz et al. (+11 more)

We present multi-epoch, multi-frequency radio observations of the tidal disruption event (TDE) AT 2022wtn, obtained with the Karl G. Jansky Very Large Array (VLA) and Giant Metrewave Radio Telescope (GMRT), spanning 97-866 days after optical detection. The peak radio flux density increases until 300 days post optical discovery, flattens out for several hundred days, then begins to decrease at 534 days. Utilizing an updated equipartition analysis framework, we estimate several physical parameters of the event and the surrounding medium. We model AT 2022wtn with two different geometries: a spherical and a conical emitting region. The spherical outflow model gives an expansion velocity of $v\approx0.21c$ and a kinetic energy of $\sim3.8\times10^{49}$ erg, and the conical outflow model yields a higher energy ($\sim1.8\times10^{50}$) and velocity ($v\approx0.41c$) than the spherical case. After ruling out the possibility of a relativistic jet, we consider several potential origins for sub-relativistic outflow regions in TDEs including unbound debris streams, collisionally-induced outflows, an accretion-driven wind, and an outflow from an accretion disk state transition, and find only an accretion disk state transition outflow to be consistent with the high energy and velocity found in our equipartition results. AT 2022wtn is a uniquely powerful non-relativistic radio-emitting TDE, and joins a growing population that display a diverse range of outflow properties.
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All authors Gavin Farley, Tanmoy Laskar, Noah Franz, Collin T. Christy, Coleman Rohde, A. J. Goodwin, Kate D. Alexander, Edo Berger, Yvette Cendes, Ryan Chornock, Tarraneh Eftekhari, Walter W. Golay, Wenbin Lu, Raffaella Margutti

High Energy Physics (Experiment)

Data Preservation in High Energy Physics: Global Report 2026

Matthew Bellis, Jamie Boyd, Daniel Britzger et al. (+46 more)

This document summarizes the contributions to the 5th DPHEP workshop March 5-6, 2026, CERN, and reflects the advancements since 2024, as well as future milestones and tendencies. Impressive progress in HEP data preservation is observed. Legacy data revival was showcased through successful reanalysis of archived data using contemporary methods, demonstrating the long-term scientific value of preservation. Sustainability challenges were noted, emphasizing the need for long-term funding and institutional support to maintain data preservation infrastructure, particularly for legacy experiments transitioning to archival modes. Innovative transverse projects display constant progress towards common technologies for a robust and transferrable DP. In particular, there is a clear shift toward automation, with increasing use of AI and machine learning for data curation, metadata extraction, and workflow optimization. Open science momentum is growing, with wider adoption of FAIR principles and open data policies, and experiments committing to public releases.
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All authors Matthew Bellis, Jamie Boyd, Daniel Britzger, Andy Buckley, Chris Burr, Micheal Buchar, Gang Chen, Andrew Chisholm, Jiri Chudoba, Michael Davis, Cristinel Diaconu, David Dobrigkeit Chinellato, Marcus Ebert, Apranik Fatehi, Dillon S. Fitzgerald, Jose Benito Gonzalez Lopez, Richard William Gran, Giovanni Guerrieri, Martin Habedank, Hao Hu, David Horvat, Luka Lambrecht, Clemens Lange, Kati Lassila-Perini, Jerome Lauret, Jean-Yves Le Meur, Dietrich Liko, Panna Liptak, Zach Marshall, Thomas McCauley, Cameron Duncan McClymont, Wesley Middelbos, Micha Moskovic, Piet Nogga, Ryunosuke O'Neil, Stefano Piano, Alan Price, Tomasz Procter, Fazhi Qi, Diana Rand, Hossein Rashidi, Emily Rensch, Pablo Saiz, Ulrich Schwickerath, Tibor Šimko, Andrii Verbytskyi, Dirk Zerwas, Zhengde Zhang, Graham Wilson

High Energy Physics (Phenomenology)

Natural Phantom Dark Energy from a $\mathbb{Z}_N$–Axion

Cédric Delaunay and Admir Greljo

We present a technically natural microscopic realization of apparent phantom dark energy based on an axion coupled to $N$ copies of two-flavor dark QCD related by a $\mathbb{Z}_N$ exchange symmetry. The symmetry exponentially suppresses the axion vacuum potential, naturally generating the dark-energy scale, while reheating into a single dark sector induces a controlled breaking of $\mathbb{Z}_N$ that simultaneously restores the physical axion periodicity, sets the dark-matter abundance, and drives the late-time dark-energy dynamics. The selected sector contains dark-pion dark matter, whose finite density initially traps the axion away from its vacuum minimum. As the Universe expands and the dark-pion density redshifts away, the axion is released and rolls on the reheating-induced vacuum potential, generating an effective phantom crossing without tuned cancellations. We identify a viable parameter region that simultaneously reproduces the observed dark-matter relic abundance and dark-energy scale, satisfies cosmological and astrophysical constraints, and qualitatively reproduces the DESI preference for an evolving dark-energy equation of state.
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High Energy Astrophysical Phenomena

A Self-Consistent Framework for Synchrotron Equipartition Analysis

Coleman Rohde, Tanmoy Laskar, Noah Franz et al. (+3 more)

Determining the energy, size, and velocity of synchrotron-emitting outflows is essential for testing models of their formation and evolution, but these quantities are often poorly constrained by observations alone. Equipartition analysis, therefore, provides a widely used framework for estimating these properties. Prior works have developed refinements to account for additional physical effects and other sources of energy (e.g., self-absorption, hot protons, and deviations from strict equipartition); however, these corrections are typically applied independently of one another, resulting in internal inconsistencies. In this work, we derive a self-consistent equipartition framework that accounts for the interdependence of various correction factors for Newtonian outflows and on- and off-axis relativistic jets. We implement our framework in an easy-to-use, publicly available code and apply it to study the tidal disruption events ASASSN-19bt and AT2019dsg, fast X-ray transient EP240414a, and active galactic nucleus J0231-0433. The interdependence of the corrections can increase energy estimates by a factor of ~5, suggesting that the energies of other synchrotron sources may be similarly underestimated in the literature. These results indicate that simultaneously incorporating these correction factors is essential for determining accurate outflow properties and constraining launch mechanisms.
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All authors Coleman Rohde, Tanmoy Laskar, Noah Franz, Gavin Farley, Collin Christy, Kate D. Alexander

Earth and Planetary Astrophysics

Unveiling the Nature of C/2023 A3 (Tsuchinshan-ATLAS): A Multi-Technique Observational Approach

Goldy Ahuja, Shashikiran Ganesh, Aravind Krishnakumar et al. (+3 more)

Comet C/2023 A3 (Tsuchinshan-ATLAS) is a non-periodic dynamically new Oort cloud comet that was discovered independently by Purple Mountain Observatory in China and Asteroid Terrestrial-impact Last Alert System (ATLAS) telescopes in South Africa. The comet passed perihelion at a distance of 0.39 AU on 27 September 2024. It was visible to the naked eye (the brightest since the comet C/1995 O1 (Hale-Bopp)) and was dubbed the great comet of 2024. In this work, we investigate the nature of this comet, which is moving in a hyperbolic orbit (e > 1), by analysing its composition using various observational techniques and tracing its orbital evolution through high-precision N-body simulations.
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All authors Goldy Ahuja, Shashikiran Ganesh, Aravind Krishnakumar, Devendra K. Sahu, Thirupathi Sivarani, Vikrant K. Agnihotri

Quantum Physics · Cross-listed from cs.AI

QANTIS: Hardware-Calibrated Sequential POMDP Belief Updates on IBM Heron

Bayram Yuksel Eker, Suayb S. Arslan, Ozgur Nazli et al. (+2 more)

Autonomous systems under partial observability act on beliefs, not raw sensor events. QANTIS treats the quantum processor as a calibrated belief-update service in that loop: it receives a prior and an observation model, estimates the rare-event evidence term, and returns an ordinary posterior to a classical planner. This paper asks whether that service can be reused across a sequential Tiger POMDP horizon on present IBM Heron hardware without corrupting the planner-facing posterior. We answer with a controlled hardware case study rather than an end-to-end autonomy or wall-clock speedup claim. The study compares no amplification, guarded Grover amplification, and all-step fixed-point amplification on the same trajectory, then checks whether the returned posterior would change the downstream action. All-step FPAA preserves the Tiger posterior across the reported 8-step and 12-step primary runs, and the 20-step and 32-step controls remain inside the same operating band. In every reported decision check, the hardware posterior and the exact Bayes posterior select the same immediate action. Boundary-aware BIQAE stabilizes amplitude estimation near zero and near one, while a rare-event sweep maps the logical sample-complexity envelope for one-in-a-million evidence. The result is an operating envelope for a hardware-calibrated belief-update primitive, not a standalone hardware-advantage claim.
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All authors Bayram Yuksel Eker, Suayb S. Arslan, Ozgur Nazli, Mustafa Serhat Demirgil, Furkan Deligoz

Accelerator Physics

Five-Dimensional Beam Sigma Matrix Determination in Transport Lines with Differentiable Simulation

Chenran Xu, Louis Emery, Osama Mohsen et al. (+4 more)

Precise measurement of the beam sigma matrix is essential for matching the optics in transport lines and ensuring reliable accelerator operation. In this work, we present a method for measuring and reconstructing the non-temporal five-dimensional beam sigma matrix using quadrupole scans performed in a dispersive transport region. The proposed approach enables characterization of the beam moments using only quadrupoles and beam transverse profile diagnostics, without requiring longitudinal diagnostics or a dedicated beamline section. To achieve robust and computationally efficient reconstruction, we formulate the problem within a differentiable simulation framework, allowing direct gradient-based optimization of the initial beam covariance matrix. We demonstrate the method experimentally in the Booster-to-Storage-ring (BTS) transport line at the Advanced Photon Source (APS), where it produces consistent reconstructions of the beam sigma matrix from measurements. We further show that the framework is flexible with respect to the number and placement of diagnostic screens, making it applicable to a broad range of existing transport-line configurations. These results establish the proposed 5D beam sigma matrix reconstruction method as a practical and broadly deployable approach for fast, efficient beam characterization during accelerator operation.
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All authors Chenran Xu, Louis Emery, Osama Mohsen, Ryan Roussel, Kent P. Wootton, Yine Sun, Michael Borland

Materials Science

Topological charge, helicity and vorticity conservation and the reverse spin-current model in the II-nd type multifferoics

Pavel A. Andreev

The topological charge and its density are related to the spin vorticity, while the spin vorticity is a part of full vorticity of the medium. The full vorticity is related to an integral of motion called the hydrodynamic helicity. Relation between two integrals of motion (the topological charge and the hydrodynamic helicity) is traced. The role of the spin-current model of the electric polarization formation due to the specific spin distribution in the helicity conservation is demonstrated. The reverse spin-current model is suggested to demonstrate the contribution of the polarization in the spin evolution equation, its importance for the helicity conservation is shown as well. Spin-field model of the electric polarization is the second model for the electric polarization (the deformation, firstly) formation due to the specific spin distribution, which appears from the same principles, but it has nonstationary origin. Moreover, the reverse spin-current model gives a mechanism for the spin structure formation due to the electric polarization in the system. It also appears as the requirement for the conservation of the helicity and the topological charge.
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Astrophysics of Galaxies

Joint constraints on gravity and stellar orbital anisotropy in massive galaxies

Wei Du, Liping Fu, Gong-Bo Zhao et al. (+5 more)

Strong gravitational lensing combined with stellar dynamics provides a complementary route for testing gravity on kiloparsec scales and probing the internal structure of massive galaxies. However, such studies remain limited by degeneracies among the mass-density profile, stellar orbital anisotropy and external convergence, and by modelling assumptions, especially when only single-aperture velocity dispersions are available. Here we develop a hierarchical Bayesian framework to disentangle gravity and stellar orbital anisotropy from other effects at the population level. By reconstructing the lens mass distribution with a flexible broken power-law model and propagating its posterior uncertainty into the predicted velocity dispersion, we obtain a likelihood for each lens in the plane of stellar orbital anisotropy and an effective mismatch parameter. This parameter encapsulates projection bias, external convergence, cosmological distance ratios and deviations from general relativity via the post-Newtonian parameter $\gamma_{\rm PPN}$. Applying this framework to 121 galaxy-scale lenses, we find $\gamma_{\rm PPN}=1.027^{+0.099}_{-0.095}$, consistent with general relativity, and obtain $2\sigma$ evidence that the stellar orbits of massive galaxies have become more radially biased over the past $\sim6$ Gyr. Forecasts show that future samples of order $10^5$ lenses could enable sub-percent tests of gravity, precise measurements of orbital-structure evolution and complementary constraints on the cosmological matter-density parameter.
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All authors Wei Du, Liping Fu, Gong-Bo Zhao, Yiping Shu, Shuo Yuan, Zuhui Fan, Huanyuan Shan, Chenggang Shu

High Energy Physics (Phenomenology)

Phenomenology of Leptophilic Gauge Interactions at Future $e^+e^-$ Colliders

S. O. Kara

We present an observable-driven study of leptophilic gauge interactions mediated by a neutral vector boson $Z_\ell$ at future $e^+e^-$ colliders. Focusing on the process $e^+e^- \to \mu^+\mu^-$, we investigate the sensitivity of angular observables to off-shell leptophilic interactions in regimes where interference effects dominate over resonant rate enhancements. The analysis is centered on the forward-backward asymmetry, which provides a robust probe of interference-induced angular deformations and retains sensitivity well beyond the resonance region. To characterize the relative angular response independently of the overall rate modification, we additionally introduce the interference-normalized quantity $\mathcal{I}_{\rm FB}$ as a diagnostic observable. Realistic collider effects, including initial-state radiation, beamstrahlung, and finite energy resolution, are consistently incorporated. Using benchmark configurations for FCC-ee, CEPC, ILC, and CLIC, we derive projected sensitivities in the $(M_{Z_\ell}, g_\ell)$ plane. The results demonstrate the complementarity between high-luminosity circular colliders and high-energy linear colliders, reflecting the interplay between precision measurements and the energy enhancement of interference effects. Overall, the present framework provides an experimentally grounded approach for probing leptophilic gauge interactions through interference-sensitive angular observables at future lepton colliders.
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Quantum Physics

Feynman's clock and hierarchy-informed sampling for quantum error mitigation

Theo Saporiti

Near-term physical implementations of quantum algorithms require efficient quantum error mitigation schemes to reduce quantum noise. In this letter we propose a new mitigation technique, by extending the applicability of our BBGKY-ISM scheme from quantum simulations of spin chains to arbitrary quantum circuits. We map executions of quantum circuits using Feynman's clock Hamiltonian to the Hamiltonian dynamics of a corresponding quantum system, whose time evolution obeys a BBGKY-like hierarchy of equations informing the BBGKY-ISM mitigation. We show that the method's classical and quantum overheads are polynomial in the circuit size and in the number of qubits. We apply our method to numerical simulations of tunable Bell state preparation circuits under state-of-the-art quantum noise, and numerically demonstrate its systematic and controllable quantum error reduction capability.
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Quantum Gases

Majorana physics in a Luttinger liquid with attractive interactions

Francesco Debortoli, Nitya Cuzzuol, Luca Barbiero et al. (+1 more)

Majorana zero modes are the hallmark of topological superconductivity. In one-dimensional systems, these zero modes are usually introduced in the context of gapped, mean-field models that do not conserve particle number, such as the Kitaev chain. By non-locally encoding a conventional fermion across spatially separated Majorana zero modes, these systems become inherently immune to local decoherence. In this work, we show that signatures of Majorana edge physics persist in a number-conserving, gapless Luttinger liquid of spinless fermions with short-range attractive interactions. We identify the two-point correlator as a sharp diagnostic, revealing an edge-to-edge revival whose sign depends on the fermion-number parity. This revival is robust in the thermodynamic limit, and persists in the excited states of the system and at different fillings. A simple particle-hole ansatz for the ground state of the system with an odd number of fermions captures the physics of the system for a wide range of interaction strengths, interpolating between the free-fermion limit and the strongly interacting Majorana regime. Finally, we propose a concrete protocol to realize this model with ultracold dipolar molecules or atoms in an optical lattice, and to detect the revival via beam-splitter interferometry, opening an experimental route to Majorana physics beyond the conventional gapped-superconductor paradigm.
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All authors Francesco Debortoli, Nitya Cuzzuol, Luca Barbiero, Fabian Grusdt

Instrumentation and Detectors

Design and Repeatability Assessment of an RF MEMS Switching Platform for Automated Microwave SOL Calibration

Edoardo Boretti, Nicola Pompeo, Enrico Silva et al. (+2 more)

This work presents a compact RF MEMS switching platform for automated one-port SOL calibration of microwave lines. The system is based on a Menlo Micro MM5230 SP4T RF MEMS switch integrated on a grounded coplanar waveguide board and driven by a dedicated MM101-based high-voltage control circuit. The board design is presented, and the repeatability of the calibrated reflection coefficient is assessed through the covariance matrix evaluated from 100 repeated SOL calibration measurements. The platform is tested from 100~kHz to 20~GHz with a Rohde & Schwarz ZNB43 VNA and the performance compared with an electromechanical microwave switch. The RF MEMS fixture shows lower dispersion of the calibrated reflection coefficient and improved temporal stability, demonstrating its suitability for repeatable automated microwave calibration in measurement environments where compactness, low mass, thermal constraints, and reduced power dissipation are key requirements.
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All authors Edoardo Boretti, Nicola Pompeo, Enrico Silva, Kostiantyn Torokhtii, Andrea Alimenti

Fluid Dynamics

Computational Fluid Dynamics and Discrete Dipole Approximation Applied to Predict Airborne Viruses Disinfection by Ultraviolet Irradiation

Talib Dbouk and Maxim Yurkin

Ultraviolet (UV) inactivation of airborne viruses involves coupled multiphysics and multiscale processes, yet UV scattering within virus-laden saliva droplets is commonly neglected. Here, for the first time we combine computational fluid dynamics (CFD) and the discrete dipole approximation (DDA) to investigate the influence of droplet-scale UV scattering on airborne virus inactivation. A benchmark CFD-DDA case study is developed and demonstrated that infected saliva droplets can exhibit highly non-uniform UV scattering under representative flow and irradiance conditions. This non-uniformity can substantially affect the predicted number of surviving viral copies, $N_s$ , indicating that UV scattering should be considered when modeling UV-based airborne disinfection systems. We systematically investigate the effect on $N_s$ by varying: the initially emitted saliva droplets diameter distribution, their number ($n(t = 0) = 10^3$ or $10^4$), volumetric airflow rate ($Q_v$ = 100, 150, or 200 $m^3/h$), droplet-wall interaction (stick vs escape), and coronavirus UV susceptibility constant (Z = 0.018 or 0.377 $m^2$/J). The simulations consider initially infected saliva droplets containing $7.4 \times 10^8$ RNA copies/mL, with a viral capsid diameter of $d_{cap}$ = 100 nm, at an air temperature of 21 {\deg}C and relative humidity of 65%. UV irradiation is represented by a 10 W cylindrical UV-lamp (34.3 mW/$cm^2$). The DDA results further enable development of an extended virus-inactivation model based on the classical Chick-Watson law that accounts for UV scattering in both spherical and nonspherical infected droplets. The results highlight the importance of resolving local UV-droplet interactions in airborne virus disinfection models and demonstrate the potential of the coupled CFD-DDA approach for improving the design and performance of UV-based airborne disinfection systems.
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Astrophysics of Galaxies

CRexit observed: probing cosmic ray transport in the circumgalactic medium with absorption line spectra

Matthias Weber, Timon Thomas, Christoph Pfrommer et al. (+1 more)

Cosmic rays (CRs) likely provide dynamically important non-thermal pressure support in the circumgalactic medium (CGM), but how their transport physics shapes observable absorption signatures remains uncertain. We investigate whether absorption-line diagnostics can distinguish between different CR transport regimes in CR-pressure-dominated halos. Using high-resolution simulations, we generate synthetic spectra along large ensembles of sightlines and measure column densities, equivalent widths, covering fractions (CFs), velocity widths, abundance ratios, and stacked absorption profiles for ions tracing cool, warm, and hot gas. We find that the effective CR transport speed strongly regulates the multiphase structure of the CGM. Efficient CR transport enhances the formation of cool ($T\sim10^4$ K) and warm ($T\sim10^5$ K) gas, leading to deeper and broader absorption lines of low- and intermediate-ionization species. The two-moment CR transport model produces the strongest MgII and SiII absorption and reaches MgII CFs consistent with the range inferred for star-forming galaxies. In contrast, slow CR transport underproduces cool, low-ionization gas and yields substantially weaker absorption. We also find that the origin of CIV-bearing gas changes with CR transport: slow transport mainly produces extended warm halo gas, whereas efficient transport shifts much of the CIV absorption into mixing layers around cool clouds. The high-ionization tracer OVI responds more weakly, indicating that CR transport primarily regulates the cool condensed phase and its interfaces rather than the volume-filling hot halo. These findings suggest that absorption-line measurements of cool and transition-phase gas can provide valuable constraints on the effective transport of CRs through the CGM.
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All authors Matthias Weber, Timon Thomas, Christoph Pfrommer, Tanya Urrutia

Materials Science

First-Principles Investigation of the Al-V Phase Diagram

AKM Sadman Mahmud, Hassan Albuhairan, Marek Mihalkovic et al. (+1 more)

The Al-V alloy system contains a number of phases including several with complex structures and at least two exhibiting sites of partial occupation. Through electronic density functional theory-based total energy calculations combined with methods of statistical mechanics, we examine the relative stability of phases at finite temperatures. We construct composition-continuous free energy models for the V-rich solid solution and for one of the complex intermetallic phases. In the V-rich region, we identify three ground states that transform to the solid solution at elevated temperatures. We also suggest that \phase{Al}{V_3} takes the Al15 structure as an intermediate-temperature phase stabilized by anharmonic vibrational free energy.
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All authors AKM Sadman Mahmud, Hassan Albuhairan, Marek Mihalkovic, Michael Widom

High Energy Physics (Theory)

Integrable systems inspired by DAHA and DIM algebra: type $C^\vee C$ versus type $A$

L. Bishler, A. Mironov and A. Popolitov

The Ding-Iohara-Miki (DIM) algebra (quantum toroidal algebra of $\widehat{gl_1}$) is related to a wide class of quantum many-particle integrable systems, a typical one being the Ruijsenaars trigonometric system with eigenfunctions that are a triad formed by the Noumi-Shiraishi power series, the Macdonald polynomials, and the Baker-Akhiezer multivariable function. Other integrable systems of this type are obtained from the Ruijsenaars system by twisting. At the same time, the Ruijsenaars Hamiltonians are directly related to the Hamiltonians of another quantum integrable system, the Cherednik DAHA Hamiltonians of type $A$ (and their twisted versions in the twisted case), due to the correspondence between the DIM algebra and the spherical DAHA. The eigenfunctions of the DAHA Hamiltonians are non-symmetric Macdonald polynomials. Similarly, there is a class of integrable DAHA Hamiltonians of type $C^\vee C$, the spherical version of which, in turn, allows one to generate integrable Koornwinder Hamiltonians. The eigenfunctions of these two integrable systems are, respectively, non-symmetric and symmetric Koornwinder polynomials, which are our main interest in this paper. Here we consider the cases of both type $A$ and type $C^\vee C$ systems, since they are sufficiently similar, and point out important distinctions between them.
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