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Physics

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Wednesday 5 August

Chaotic Dynamics

A Symplectic Map Approach to Magnetic Field-Line Dynamics in Tokamaks

Diego F. M. Oliveira and Edson D. Leonel

Magnetic field-line transport in tokamaks is governed by the interplay between chaotic dynamics and invariant phase-space structures that act as partial transport barriers. We investigate the conservative Tokamap, an exact symplectic mapping for magnetic field-line dynamics, using a unified geometrical, dynamical, and statistical framework. Phase-space portraits and Lyapunov exponents characterize the mixed Hamiltonian dynamics, while ensemble-averaged transport exhibits universal dynamic scaling with growth, crossover, and saturation regimes connected through a homogeneous scaling theory. Poincaré recurrence statistics reveal that decreasing the magnetic-shear parameter systematically slows transport, with the characteristic transport time following the algebraic scaling $\tau_c\propto x_q^{-0.213}$. This behavior reflects increasingly dominant stickiness associated with KAM islands, resonance chains, and cantori. Our results establish a direct connection between the geometrical organization of Hamiltonian phase space and macroscopic transport properties, providing a comprehensive framework for understanding long-time magnetic field-line transport in tokamaks and other Hamiltonian systems with mixed phase space.
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Quantum Physics

Interferometric Quantum Polynomial Chaos Expansion as a Generative Model for Calorimeter Shower Simulation

Jamal Slim, Saverio Monaco, Florian Rehm et al. (+3 more)

We present the quantum polynomial chaos expansion, a generative algorithm in which a single circuit is the entire model, and we use it to learn calorimeter images. In a classical chaos expansion the randomness is the input and the coefficients are fitted. Here the randomness is still the only input, entering the circuit as rotation angles and re-uploaded at every block, so that each measured observable is a chaos expansion of the latent variables whose order equals the circuit depth, and what is fitted are the gate angles themselves. Expressivity therefore grows with depth rather than with classical coefficients, correlations between outputs arise only from entangling gates, and a single latent wire read by all qubits carries the collective mode of the data. Nothing fitted stands between the circuit and the sample, so switching the entanglers off is a setting of the model itself and provably yields independent outputs, and attribution of the learned correlations to individual gates becomes a measurement. Choosing between two measurement bases shot by shot sharpens attribution into certification, and the trained model violates the Bell bound obeyed by every classical generative model with local response, whatever its size. We train the model on Geant4 shower data, execute the identical circuit on a superconducting processor with its accuracy loss predicted in advance, prove a no-go theorem for the tail dependence of every smooth generator read out through expectation values, and identify the circuit primitive that removes this limit.
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All authors Jamal Slim, Saverio Monaco, Florian Rehm, Dirk Kruecker, Frank Gaede, Kerstin Borras

Instrumentation and Methods for Astrophysics

Development of next-generation event-driven x-ray hybrid CMOS detectors

Timothy R. Emeigh, Abraham D. Falcone, Joseph M. Colosimo et al. (+14 more)

The Penn State University High Energy Astrophysics Detector and Instrumentation Lab, in collaboration with Teledyne Imaging Sensors, has developed a next-generation event-driven X-ray hybrid CMOS detector. This detector is an HCD with a 1,024x1,024 array of 21-micron pitch pixels, featuring a comparator in each pixel to enable event-driven readout. While the full frame operation of this detector can reach readout speeds of up to 150 Hz, this event-driven operation allows readout of only those pixels that surpass a user-set charge threshold, enabling effective rates of up to 10 kHz. Here we report on the past detector development efforts at Penn State and describe these new detectors and expected performance improvements.
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All authors Timothy R. Emeigh, Abraham D. Falcone, Joseph M. Colosimo, Kadri M. Nizam, Lukas R. Stone, Md. Arman Hossen, Laurel ONeill, Ian Ashcroft, Kyle Bonene, Brynn Bortree, Zachary E. Catlin, Sierra Deppe, Killian M. Gremling, Gavin Houlihan, Katie McWhirter, David M. Palmer, Abigail A. Raytsis

High Energy Physics (Phenomenology)

HiggsTools for LHC Run 3 and Beyond

Henning Bahl, Thomas Biekötter, Sven Heinemeyer et al. (+2 more)

HiggsTools, including the subpackages HiggsPredictions, HiggsBounds, and HiggsSignals, is a toolbox for Beyond-the-SM (BSM) scalar phenomenology at the LHC. It provides BSM model predictions, tests the model against experimental limits from searches for BSM scalars and derives constraints from the measurements of the properties of the discovered Higgs boson. We present a variety of improvements to the HiggsTools framework, preparing it for the results of LHC Run 3 and the HL-LHC. HiggsPredictions now provides additional cross-section predictions for centre-of-mass energies of 13.6 and 14 TeV. Moreover, it now includes cross-section predictions for resonant and non-resonant Higgs-boson pair production. For HiggsBounds, we describe the recasting of searches using multi-top final states, explain their implementation and highlight the impact of the experimental sensitivity of those results. Furthermore, we discuss the implementation of coupling-dependent limits on non-resonant Higgs boson pair production, as well as the improved handling of searches conducted prior to the Higgs boson discovery. For HiggsSignals we describe several improvements for the case of scalars with mass uncertainties.
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All authors Henning Bahl, Thomas Biekötter, Sven Heinemeyer, Kateryna Radchenko Serdula, Georg Weiglein

Computational Physics

Multiphysics tritium transport modelling of the ARC breeding blanket with FESTIM

James Dark, Arpan Sircar, Jin Whan Bae et al. (+2 more)

Accurate prediction of tritium behaviour in molten salt breeding blankets is essential for the design and safe operation of ARC-class fusion reactors. This work presents a fully open-source, component-scale multiphysics framework for modelling tritium transport in an ARC liquid immersion blanket. Neutron transport, thermal hydraulics, and hydrogen isotope transport are coupled using OpenMC, OpenFOAM, and FESTIM, leveraging dedicated tools enabling direct transfer of spatially resolved fields between solvers. Assuming a zero inlet concentration, steady-state simulations predict a total tritium inventory of approximately 243 mg, with the blanket reaching steady-state tritium throughput within approximately 30 min, which is of a similar order to previous system-level estimates. The results show that tritium transport is dominated by turbulence-enhanced diffusion, with strong localisation in flow stagnation regions and reduced accumulation in highly turbulent zones. Sensitivity analyses indicate that predicted inventories are governed primarily by the numerical stabilisation scheme, with only a modest dependence on the turbulent Schmidt number. The proposed workflow provides a transparent and extensible basis for high-fidelity analysis of tritium transport in ARC-class breeding blankets.
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All authors James Dark, Arpan Sircar, Jin Whan Bae, Jørgen S. Dokken, Rémi Delaporte-Mathurin

Instrumentation and Methods for Astrophysics

Proof of concept of the COSMOCal project at the IRAM 30m telescope

S. Savorgnano, L. Bizzarri, A. Ritacco et al. (+25 more)

This work reports on a test campaign conducted at the IRAM 30m telescope to validate the COSMOCal instrument, a novel concept for absolute calibration of polarization angle, beam properties, and instrumental efficiency. The development is motivated by the stringent calibration requirements of current and next-generation Cosmic Microwave Background (CMB) experiments, whose goal is the precise measurement of CMB polarization. Such measurements are essential to probe fundamental physics, including the possible imprint of primordial inflation. The COSMOCal concept is designed as a space-borne calibration reference intended to provide a stable and absolute polarized signal observable simultaneously by multiple large-aperture ground-based observatories. Prior to any space deployment, a terrestrial prototype was developed and characterized in the laboratory, as reported in Ritacco et al. 2024. The results presented here describe the first validation of the system coupled to an antenna, carried out at the IRAM 30m telescope in September 2024. This campaign aimed at assessing the performance of the full instrument under realistic observational conditions, including its ability to reconstruct polarization observables and interface with a state-of-the-art millimeter-wave polarimeter.
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All authors S. Savorgnano, L. Bizzarri, A. Ritacco, J. Aumont, F. Boulanger, A. Catalano, F. Cuttaia, A. Denis, F.-X. Désert, D. González Ovejero, S. Leclercq, J.-F. Macías-Pérez, B. Maffei, M. Migliaccio, L. Montier, P. Morfin, L. Mousset, M. Murgia, F. Nati, P. Ortu, M. Pérault, G. Pisano, T. Pisanu, N. Ponthieu, L. Terenzi, J. Treuttel, L. Vacher, M. Zannoni

Quantum Physics

Feasibility-Preserving Quantum Search for Constrained Transportation Routing

Dahye Kim and Monika Filipovska

Transportation routing problems such as the Traveling Salesperson Problem (TSP) and the Vehicle Routing Problem (VRP) are characterized by strict feasibility requirements involving customer assignment and visit rules, route sequencing, and depot-return logic alongside cost minimization. Most quantum routing formulations adopt Quadratic Unconstrained Binary Optimization (QUBO) encodings, where feasibility is incorporated indirectly via penalty terms in the cost Hamiltonian. While convenient for standard implementations of the Quantum Approximate Optimization Algorithm (QAOA), QUBO encodings allow the quantum search dynamics to allocate substantial probability to infeasible route configurations. This study develops a transportation-grounded constraint-aware Quantum Alternating Operator Ansatz (QAOA+) framework that embeds feasibility-preserving logic directly into the search operator. We introduce a custom mixer that functions as a quantum analogue of feasibility-preserving routing neighborhoods, using column-wise swap moves, it restricts evolution to feasible configurations while enabling structured exploration of valid routes. We compare three constraint-handling architectures: penalty-based QUBO QAOA, penalty free QAOA+ with the feasibility-preserving mixer, and a Hybrid QAOA+ combining mixer based feasibility with and penalty guidance. Results on small TSP and VRP instances show that constraint-handling architecture strongly influences feasible-route sampling, convergence behavior, and probability concentration over low-cost feasible routes. These findings position constraint-aware quantum search as a methodological extension of transportation routing search approaches, where feasibility is enforced through admissible quantum transitions rather than post-hoc penalties.
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Chemical Physics

Next Generation of Ultra-Coarse-Graining: Self-Consistent Inference of Critical Internal States

Weizhi Xue, Xiao Shuai and Gregory A. Voth

Bottom-up coarse-graining expands the length and time scales accessible to molecular dynamics (MD) simulations, but information loss can hinder accurate representation of multistate phenomena in complex biomolecular dynamics. Ultra-Coarse-Graining (UCG) projects discrete "quantum-like" extended degrees of freedom, or "internal states," onto coarse-grained (CG) molecules, extending CG model expressiveness. The rapid-local-equilibrium (RLE) approximation in UCG depends on user-defined collective variables (CVs, e.g., local density) and neglects correlations between internal states within and between CG molecules. We present Self-Consistent UCG (SC-UCG), which uses the underlying UCG interactions directly to assign internal states without designing CVs in the CG ensemble. During simulation, internal state probabilities are determined self-consistently through graph message passing. We enhance the RLE Hamiltonian with the Bethe approximation and AI-based inference to represent explicit correlations between UCG beads. For force-field training, we develop Multilayer Internal State Consistency (MISC), a machine-learning method derived from relative entropy minimization that avoids iterative sampling of intermediate force fields. We apply SC-UCG to a tetramer exhibiting a second-order symmetry-breaking phase transition from a supercritical racemic fluid to subcritical D-rich and L-rich fluids. SC-UCG captures collective switching of internal states in the subcritical region and recapitulates the phase transition across temperatures, despite being trained on a single-temperature dataset.
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Materials Science

Fine-Tuning Small Language Models for Reliable VASP INCAR Generation

Xinyue Zhang, Jixiang Li, Bin Shao et al. (+3 more)

Language models can prepare VASP INCAR files from natural-language requests, but so far only large proprietary cloud models come close to handling the tightly coupled, physics-sensitive settings reliably, a dependence that fits poorly with local, high-throughput materials workflows where privacy, cost, and offline deployment matter. We show that a small language model (SLM) can close this gap. The SLM is fine-tuned on reference VASP calculations and paired with VASPGuard, a deterministic post-processor that checks syntax, workflow, and material-dependent constraints; we call the combined model INCAR-SLM. On INCARBench, a benchmark for VASP INCAR generation, INCAR-SLM built on Qwen3-4B outperforms every general-purpose LLM evaluated, exceeding GPT-5.4 by 15.55 points on the 100-point INCAR Score. Most of this gain comes from fine-tuning, with VASPGuard correcting the errors that remain. We further find that model size matters less than expected: once fine-tuning and post-processing are applied, performance saturates at a few billion parameters, and Qwen3-4B outperforms larger models in the same family.
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All authors Xinyue Zhang, Jixiang Li, Bin Shao, Baishun Yang, Zhiyang Liu, Weichao Wang

Instrumentation and Methods for Astrophysics

Graph reconstruction from random-walk co-visitation: Geometric, empirical, and controlled networks

Marko Imbrišak and Krešimir Tisanić

Reconstructing an unknown graph from the trajectory of a random walk arises both for spatial correlation networks in astrophysics and for connectivity inference in network science. We present a reconstruction pipeline whose observable is the random-walk co-visitation matrix, whose model is a pairwise edge-weight basis, and whose fitter is a frame-balanced Levenberg-Marquardt (fbLM) scheme with per-node group weights and a self-calibrated edge readout. Unlike the marginal occupation, the co-visitation retains the ordered pair before the row sum is taken, and the pairwise basis can represent structure that an additive node-potential model cannot; neither change suffices alone. We apply the pipeline to an email communication subgraph, to Delaunay and Voronoi networks built from a COSMOS sky catalogue, and to two controlled 12-vertex test graphs, one unicyclic and one a tree, under both analytic-noise and finite-walk regimes. Reconstructions are scored against the ground-truth adjacency, which enters nowhere in the fit, by true/false positives and the Matthews correlation coefficient (MCC). All test-beds are reconstructed with high fidelity at full graph size: on finite-walk data we recover the COSMOS Delaunay and Voronoi graphs at MCC above 0.98 up to their full extent, N=119 and N=223, the whole graph rather than a cut-out of it, and the empirical email-Eu-core graph at N=240 (417 edges). On the full Delaunay graph a graphical-lasso reference returns MCC 0.540 against 0.988 for fbLM. Each reconstructed edge carries a Fisher-propagated uncertainty, and the residual misses are almost entirely confined to edges the walk never traverses. In the finite-walk regime the limiting factor is therefore walk coverage rather than the fit: essentially every edge the walk visits is recovered, so reconstructibility is governed by the sampling of the graph rather than by the estimator.
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Optics

High Spectral Energy Density All-Fiber Nanosecond Pulsed 1.7 $\mu$m Light Source for Photoacoustic Microscopy

Seongjin Bak, Sang Min Park, Yuon Song et al. (+7 more)

We present a high spectral energy density all-fiber nanosecond pulsed 1.7 $\mu$m light source specifically designed for photoacoustic microscopy (PAM). The system targets the first overtone absorption of C-H bonds near 1720 nm within the near-infrared-III (NIR-III) window, where lipids exhibit strong optical absorption and tissues benefit from reduced scattering and high permissible fluence. To achieve narrow linewidth, high pulse energy, and high pulse repetition rate (PRR), we developed a master oscillator fiber amplifier architecture based on stimulated Raman scattering. A 1589.80 nm Raman pump and a custom-built narrow-linewidth Raman seed laser were employed to generate spectrally pure 1719.44 nm pulses with an approximately 0.10 nm linewidth. The proposed light source delivers nanosecond pulses of approximately 5 ns with high pulse energy of at least 2.2 $\mu$J and tunable PRRs up to 300 kHz, resulting in a spectral energy density of approximately 22 $\mu$J/nm, which is significantly higher than that of conventional 1.7 $\mu$m light sources. The performance of the NIR-PAM system was validated through resolution testing with a 1951 USAF target, demonstrating a spatial resolution of approximately 4.14 $\mu$m and an axial resolution of approximately 85.5 $\mu$m. Phantom imaging of CH$_2$-rich polymer films and ex vivo lipid-rich biological tissues confirmed the system's high spatial fidelity and strong contrast for lipid-specific structures. This compact, stable, and spectrally refined light source with high spectral energy density can offer an effective solution for high-resolution, label-free molecular imaging and represents a promising platform for clinical photoacoustic imaging applications involving lipid detection and metabolic disease diagnostics.
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All authors Seongjin Bak, Sang Min Park, Yuon Song, Jeesu Kim, Tae Won Nam, Dong-Wook Han, Chang-Seok Kim, Soon-Woo Cho, Brett E. Bouma, Hwidon Lee

Quantum Physics

Quantum Error Mitigation with Diffusion-Like Models

Yuval Idan, Ofek Nourian, Elad Mentovich et al. (+2 more)

Coupling between a quantum system and its environment causes decoherence by transferring information from the system to environmental degrees of freedom. When discretized in time, such interactions can be interpreted as sequences of weak measurements that provide an effective model of noisy quantum dynamics. Motivated by this picture, we propose an AI-assisted error-mitigation framework for quantum diffusion processes generated by sequential local weak measurements. The forward process progressively erases information from the input state through weak measurements performed in randomly selected Pauli bases, producing basis-dependent local dephasing and locally depolarizing dynamics on average. Machine-learning models are trained on exact synthetic density matrices to learn a channel- and distribution-specific denoising map and estimate the corresponding pre-noise state. We benchmark the approach on single-qubit states and separable and entangled multi-qubit registers. We also study distribution-dependent local-to-global reconstruction, in which local reduced density matrices are used to reconstruct the global state. This experimentally motivated setting relies on locally accessible information and is therefore compatible with noisy and distributed quantum systems. More broadly, the framework provides a hybrid classical-quantum approach for approximating non-unitary dynamics and mitigating coherence loss.
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All authors Yuval Idan, Ofek Nourian, Elad Mentovich, Taylor L. Patti, Eliahu Cohen

Quantum Physics

Maximally entangled states are not complete for pseudo-telepathy

Olivier Lalonde

One of the longstanding open problems in quantum nonlocality is to determine if maximally entangled states are complete for bipartite pseudo-telepathic games: namely, if every nonlocal game which admits a perfect entangled strategy admits such a strategy which uses a maximally entangled state. We exhibit a counterexample to this in the form of a bipartite nonlocal game with input sets of size 4 and 3 and output sets both of size 6. This game is part of a new class of nonlocal games, which we call inner product games, which could be of independent interest.
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Nuclear Experiment

ePIC Early Science Report

D. Abbott, N. Abdelrahman, S. Abhijit et al. (+796 more)

This Early Science Report from the ePIC Collaboration outlines the compelling physics program achievable during the first years of operation of the Electron-Ion Collider (EIC), prior to the establishment of the full design luminosity and energy range. The analyses are based on realistic early-running beam configurations and detailed Geant4 ePIC detector simulations, hit digitization and data reconstruction. The projected studies from the physics working groups of ePIC span inclusive, semi-inclusive, exclusive, diffractive and tagging, as well as jet and heavy flavor measurements in both electron-proton and electron-ion collisions. Even before the collider reaches its full design performance, these measurements will constrain parton distribution functions in nucleons and nuclei, access transverse-momentum-dependent and spin-dependent observables, probe gluon dynamics in nuclei, and initiate a program of imaging of quarks and gluons. Each measurement is directly connected to the core science pillars of the EIC, identified in the 2018 report by the National Academy of Sciences: understanding the origin of the nucleon mass, unraveling the spin structure of the nucleon, and exploring the emergent properties of dense gluonic matter. The results presented here provide examples that demonstrate that the early years of EIC running with ePIC will deliver novel world-leading insights into Quantum Chromodynamics. In addition, the early science program will establish measurement and analysis methodologies that will pave the way to the subsequent full EIC physics program.
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All authors D. Abbott, N. Abdelrahman, S. Abhijit, I. Abualrob, R. B. Achari, J. Adam, L. Adamczyk, K. Adkins, A. Affolder, K. Agarwal, J. Agarwala, N. Agrawal, C. A. Aidala, W. Akers, A. Al-bataineh, S. N. Alam, M. Alekseev, P. R. Altieri, J.-S. Alvarado Gallenao, S. B. L. Amar, R. Ammendola, I. Amos Cali, G. An, D. Anderson, E. Anderssen, V. Andrieux, G. Andronico, P. Antonioli, N. Apadula, D. Arkhipkin, W. Armstrong, M. Arratia, S. Arrigo, J. Arrington, M. Asai, A. Asaturyan, E.-C. Aschenauer, C. Ayerbe Gayoso, B. Azmoun, J. Bae, Y. Bae, X. Bai, V. Bailey, F. Barbosa, F. Barile, K. Barish, M. Bashkanov, S. Bathe, M. Battaglieri, A. Baty, A. Bazilevsky, T. D. Beattie, B. Beauchamp, Y. Bedfer, N. K. Behera, F. Bellini, R. Bellwied, H. Ben Hannan, M. Benettoni, M. Benoit, V. Berdnikov, J. Bernauer, H. Bervas, R. Besuner, J. Bettane, R. Bhadauriya, H. Bhatt, V. Bhopatkar, S. Bhosale, A. Biagioni, J. Bielcikova, J. Bielčík, Z. Biro, G. Boca, F. Bock, J. Bok, M. Bondi, A. Bonenfant, C. Bonini, M. Borri, F. Bossù, F. Bouyjou, O. Brand-Foissac, D. Brandenburg, N. Brei, A. Bressan, T. Britton, G. E. Bruno, M. Buckland, A. Buckley, L. Bucuru, E. Buron, A. Bylinkin, D. Cacace, H. Caines, A. Calivà, M. T. Camerlingo, P. Campero Rojas, A. Camsonne, M. Capua, F. Capuani, T. Carmarda, E. Casalotti, J. Ceska, I. Chakaberia, J. Chan, W.-C. Chang, M. Chartier, P. Chatagnon, C. Chatterjee, V. Chaumat, K.-F. Chen, Z. Chen, K.-Y. Cheng, Y. Cheng, S. Chevobbe, A. Cheyne, C. Chiarini, A. Chisari, S. Choi, P. Christoph, X. Chu, J. Chwastowski, A. Ciardiello, S. Ciarlantini, A. Cimini, E. Cisbani, Z. Citron, E. Cline, I. Cloët, D. Colella, M. Connors, M. Contalbrigo, G. Contin, S. Corey, R. Corliss, T. Cornet, F. Cossio, S. Costanza, J. Crafts, D. Cristancho, R. Cruz-Torres, A. D'Angelo, A. Dabat-Blondeau, E. Dahle, S. Dalla Torre, M. Daradkeh, S. Das, A. P. Dash, J. Datta, P. Datta, K. Davies, R. Dawson, A. De Caro, D. De Gruttola, S. De Pasquale, W. Deconinck, M. Defurne, Y. Degerli, C. Delafosse, A. Delbart, F. Delcarro, G. Dellacasa, M. Demarteau, Z. S. Demiroglu, G. W. Deptuch, A. Deshpande, D. Di Bari, B. Di Ruzza, R. Di Salvo, M. Diefenthaler, C. M. S. Divincenzo, X. Dong, B. Dongwi, V. Doomra, N. Doshita, A. Drees, R. Dupre, D. Dutta, R. Dzhygadlo, A. El Ouardi, L. El Fassi, D. Elia, B. Eng, R. Ent, Y. Eo, R. Esha, A. Eslinger, A. Evdokimov, O. Evdokimov, O. Eyser, V. Fadeyev, D. Falchieri, W. Fan, C. Fanelli, A. Fantini, F. Farrokhi, R. Fatemi, S. Fazio, S. Fegan, M. Finger, M. Finger, F. Flor, L. Flores, C. Flouzat, E. Fountain, B. Fraisse, A. Francisco, J. Frantz, S. Franzese, O. Frezza, N. Funicello, S. Furletov, Y. Furletova, C. Gal, H. Gao, M. Garbini, S. Gardner, P. Garg, D. Gaskell, V. Gaur, S. Geminiani, M. Gericke, F. Geurts, O. Gevin, T. Ghosh, P. Ghoshal, A. Gibson, I. Gildea, R. Gilman, D. Giordano, A. Giri, J. Giroux, P. Giubilato, D. I. Glazier, E. Glimos, J. Glover, K. Gnanvo, Y. Go, C. Goblin, L. Godfrey, L. Gonella, S. Gopinath, D. Gorni, M. Gouighri, S. Gramigna, K. Gray, S. V. Greene, M. Grosse Perdekamp, W. Gu, F. Guilloux, T. Gunji, J. Gupta, C. Gwenlan, T. Hachiya, E. Hagen, J. Haggerty, T. Hague, W. Ham, A. Hamed, R. Hamilton, X. Han, O. Hartbrich, M. C. Harvey, H. Hashamipour, S. Hassan, M. Hattawy, L. Havener, X. He, T. Hellstern, W. Helsby, T. Hemmick, O. Hen, S. Henry, D. Higinbotham, A. Hill, M. Hoballah, A. Hoghmrtsyan, M. Hohlmann, B. Hong, Y. Hong, T. Horn, D. Hornidge, I. Hossain, T. Hotta, C.-Y. Hsieh, Y. Hu, H. Z. Huang, J. Huang, J. Huang, S. Huang, G. Huber, A. Huddart, T. Huffman, P. Hurck, T. Hwang, C. Hyde, S. Iain, P. Iapozzuto, A. Illari, M. Inaba, G. M. Innocenti, A. Iqbal, D. G. Ireland, L. Isenhower, B. Jacak, N. Jacazio, M. Jadhav, S. Jain, H. Jang, S. Jang, O. Javakhishvili, J. Jaya, F. Jeanneau, A. Jentsch, Y. Jeong, T. Jeske, O. T. Jevons, S. Ji, J. Jia, H. Jiang, N. Jindal, H.-S. Jo, P. Jones, K. Joo, S. Joosten, A. Jung, O. Ka, G. Kainth, J. Kalani, N. Kalantarians, G. Kalicy, D. Kalinkin, M. Kaneta, K. Kauder, R. Kaundal, K. Kawade, S. Kay, M. Kebbiri, M. Kesler, A. Khanov, H. Khindri, A. Khuntia, Y. Khyzhniak, C. Kierans, A. Kim, B. Kim, B. Kim, C. Kim, E.-J. Kim, E. Kim, G. Kim, J. Kim, M. Kim, M. Kim, S. H. Kim, J. Kiryluk, A. Kiselev, J. Klay, S. Klein, H. Klest, V. Klimenko, N. Kobayashi, R. Koka, O. Korchak, I. Korover, L. Kosarzewski, A. Kostina, I. Krehbiel, A. Krieger, F. Krizek, T. Kumaoka, A. Kumar, K. Kumar, L. Kumar, R. Kumar, S. Kumar, M. Kumari, R. Kunnawalkam Elayavalli, C.-M. Kuo, T. Kutz, Y. Kwon, B.-Y. Ky, P. La Rocca, M. Labiche, R. Lacey, J. Lajoie, J. Lalic, K. Lalwani, E. Lancon, J. Landgraf, L. Lanza, R. Lassiter, D. Lattuada, J. Lauret, A. Laviron, O. Le Dortz, C. Le Gaillard, Y. Le Roux, C. Lee, H. Lee, H. Lee, J. Lee, J.-H. Lee, K. Lee, S. Lee, S. Lee, S.-J. Lee, Y.-J. Lee, S. Levorato, N. Lewis, S. Li, W. Li, W. Li, X. Li, B. Liang-Gilman, H. Lim, S. Lim, P.-J. Lin, W. Lin, M. Lisa, A. Liu, J. Liu, M. Liu, M. Liu, K. Livingston, T. Ljubicic, W. Llope, F. Lo Cicero, O. Lomický, A. Lonardo, E. Long, L. Long, R. Longo, S. Longo, R.-S. Lu, A. Lumanog, R. Ma, P. Maj, J. Mammei, F. Mammoliti, G. Mandaglio, S. Mandal, I. Mandjavidze, V. Manzari, S. Maple, D. Marchand, C. Markert, A. Martin, M. Martinelli, H. Marukyan, A. Mastroserio, G. Matousek, K. Matsutani, S. Mattiazzo, J. Maxwell, S. Mazza, B. McKinnon, A. S. Menon, J. Metcalfe, Z.-E. Meziani, A. Migayron, R. Milner, R. Milton, N. Minafra, C. Mingioni, Y. Miyachi, A. Mkrtchyan, H. Mkrtchyan, E. F. Molina Cardenas, M. K. A. Mondal, R. Montgomery, I. Mooney, B. Moreno, D. Morrison, S. Mouslih, A. Movsisyan, C. Munoz Camacho, S. Muraoka, M. Murray, T. Nagorna, C. J. Naim, A. Nambrath, S. Nanda, E. Nappi, V. Narendran, A. Natochii, V. S. Nattoja, C. Nattrass, H. Nayak, G. Nebin, D. Neff, M. Nenni, P. Newman, D. Neyret, M. Nguyen, N. Nicassio, S. Niccolai, G. Nigmatkulov, F. Noferini, P. Nord, J. Norman, R. Nothnagel, F. Noto, R. Nouicer, N. Novitzky, C. Nunez, J. Nystrand, S. Obratsov, L. Occhiuto, A. Ogawa, C. Oh, S. Oh, O. Olokunboyo, J. Osborn, M. Osipenko, S. Ota, J. Ott, G. Ottino, K. Oyama, E. O'Brien, B. S. Page, S. Pal, A. Paladino, P. Palni, A. Pandav, V. Pant, A. Panta, C. Pantouvakis, D. Panzieri, Z. Papandreou, S. Park, C. Pastore, V. K. Patel, S. Paul, S. Paul, C. Pecar, C. Peng, G. Penman, R. Perrino, P. Perticaroli, N. Pilleux, C. Pinkenburg, R. Pisani, S. Plavully, L. Polizzi, I. Ponce, L. Pontisso, M. Posik, M. Potekhin, E. Pottebaum, S. Prabhakar, R. Prabir, L. Preet, R. Preghenella, S. Priens, E. Prifti, M. Priyadarshini, I. Prochazka, T. Protzman, A. Prozorov, F. Prunes, M. Przybycien, P. Pujahari, P. Purohit, M. Purschke, B. Quni, S. Radhankrishnan, M. Radici, A. Rafaat, S. Rafael-Polcher, S. Rahman, R. Rajput-Ghoshal, A. Ramalingam, S. Rana, E. Rao, A. Rathi, F. Rathmann, A. Rathore, K. Read, P. Rebesan, R. Reed, B. Rehman, P. Reimer, G. Reis Garcia, J. S. Renck, S. Rescia, R. Ricci, J. Richards, C. Riedl, A. Riggio, L. Rignanese, M. Ripani, C. Ripoli, F. Rizatdinova, D. Rizk, J. Roche, G. Roland, D. Romanov, M. Rosati, C. Rossi, F. Rossi, E. Rovati, L. Ruan, N. Rubini, M. Ruspa, D. Ruth, J. Ryu, S.-Y. Ryu, F. Sabatié, R. Sadek, H. Sadrozinski, N. Saha, T. Sakaguchi, S. Salur, D. Samuel, P. Sanethavong, N. Santiesteban, A. Saputi, A. Sarkar, M. Sarsour, J. Schambach, B. Schmookler, B. Schumm, C. Schwarz, J. Schwiening, A. Seiden, R. Seidl, B. Seitz, H. Seong, L. Serin, Y. Shabaan, N. Shah, M. Shahid, P. Shanmuganathan, A. Sharma, D. Sharma, R. Sharma, A. Shatat, A. I. Sheikh, T.-A. Shibata, K. Shigaki, G. Shildt, T. Shin, S. Shiraskar, J. Shirk, J.-G. Shiu, N. Shouryasankar, E. Shulga, E. Sichtermann, E. Sidoretti, J. Silber, F. Simula, A. Singh, B. K. Singh, G. Singh, J. Singh, K. Slifer, N. Smirnov, A. Smith, J. Smith, K. Smith, D. Sokhan, G. Sommer, T. Song, R. Souvik, N. Speece-Moyer, F. Spizzo, M. Spreafico, N. St John, M. Stefaniak, P. Steinberg, J. Stevens, S. Stoll, E. Sun, K. Suresh, B. Surrow, M. C. Sutera, K. Sutowski, T. Sykora, H. Szumila-Vance, V. Tadevosyan, T. Takahshi, C. K. Tam, A. Tamis, U. Tamponi, X. Tan, D. Tapia Takaki, S. Tarafdar, E. Tassi, Y. Tayalati, L. Teodorescu, C. Terrevoli, F. Tessarotto, A. Teymurazyan, M. Thakur, D. Thomas, F. Thomson, A. Timmins, S. Titus, T. Toll, L. Tomasek, A.-S. Torrento, P. Tribedy, B. A. Trzeciak, O. Tsai, C. S. Tse, Z. Tu, R. Turrisi, C. Tuvé, B. Ujvári, T. Ullrich, G. M. Urciuoli, S. Vallarino, N. Valle, C. Van Hulse, M. Vandenbroucke, J. Vanek, Z. Varga, N. Vasim, J. Vasquez, S. Vasquez, J. Velkovska, G. Verde, S. Vetter, P. Vicini, G. Viehhauser, A. Vijay, A. Vijayakumar, D. Violette, T. Virgili, G. Volpe, A. Vossen, E. Voutier, F. Wang, G. Wang, P.-K. Wang, Y.-T. Wang, R. Wastie, J. Watkins, I. J. Watson, D. P. Watts, S. Welch, T. Wenaus, F. Wilson, R. Wimmer, S. Wissink, H. Witte, M. Wood, C. Woody, Y.-H. Xiao, J. Xie, W. Xie, Z. Xu, Z. Xu, Z. Xue, S. Yang, S. Yang, Y. Yang, S. Yano, Z. Ye, Z. Ye, Z. Ye, E. Yeats, K. Yip, K. Yongsun, H. Yoo, I. Yoon, D. Young, C. Yuen Tsang, N. Zachariou, W. Zha, S. Zhang, W. Zhang, Y. Zhang, Y. Zhang, Z. Zhang, Z. Zhang, Y. Zhao, Z. Zhao, V. Zhezer, B. Zihlmann, C. Zorn, M. Zurek, J. de Melo, D. de Souza Lemos, A. Accardi, I. Borsa, M. Cerutti, C. Cocuzza, J. Jiménez-López, K. Kumericki, R. Martinez, L. Rossi, P. Sznajder, A. Vladimirov, K. Wichmann, S. Yadav, P. Zurita

Instrumentation and Methods for Astrophysics

Information Geometry meets Functional ANOVA: An Exact Fisher-Information Decomposition, with an Application to Radio Luminosity Functions

Marko Imbrišak and Krešimir Tisanić

Information geometry represents a fitted model as a manifold whose metric is the Fisher information. We show that, for a nonlinear regression model, this metric decomposes exactly across the Hoeffding-Sobol' (functional ANOVA) channels of its covariates. Treating the score contributions of main effects and interactions as vectors in a Hilbert space, their Gram matrix reproduces the (Gauss-Newton) Fisher information metric exactly, and this identity extends to an exact, additive decomposition of the Fisher information matrix into main-effect, interaction, and cross-channel terms: a Sobol'-type accounting for parameter information rather than output variance, and equivalently a channel-resolved pullback of the ambient Fisher metric along the model embedding. We give the exact decomposition theorem with a short proof (deriving both the centered and uncentered Fisher information), define information-theoretic analogues of Sobol' indices, characterize the sign and finite-sample behaviour of the cross-channel terms, and describe two practical estimators. As an astrophysical application we decompose the parameter information of a combined 1.4 GHz radio luminosity-function model spanning active galactic nuclei (AGN) and star-forming galaxies (SFG), fit to 6dFGS-NVSS and VLA-COSMOS 3 GHz data: the decomposition localizes where in luminosity each population and survey constrains the fit, and exposes the compensating ("sloppy") channel combinations near the luminosity-function turnover. A plant CO2-uptake experiment serves as a small, fully categorical companion example.
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Quantum Physics

QBism on Locality and Nonlocality

John B. DeBrota, Christopher A. Fuchs and Rüdiger Schack

Recently Pienaar (2026), building on work of Cavalcanti (2021), has shown that QBism cannot always assume distinct observers' quantum-measurement outcomes—say, of Wigner and his friend—are embedded in a single spacetime. This follows from QBism's rejection of the `Absoluteness of Observed Events' assumption in the Bong et al. no-go theorem. Thus, QBism has no choice but to treat the notion of spacetime every bit as personalistic as it treats quantum states and quantum measurement outcomes. In a way, this is not a surprise to QBists, as they have taken the notion of `personalist spacetimes' to be the ansatz most compatible with their other views since at least 2009. But it does enjoin us to finally make crystal clear the sense in which QBism is a purely local interpretation of quantum mechanics despite this new theorem and despite quantum theory's age-old violation of Bell's inequalities. With the extra clarity we also hope to poise QBism for a distinctly new way to approach issues at the interface of quantum theory and gravity.
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Instrumentation and Methods for Astrophysics

Comparing the contrast performance of two IFU technologies for exoplanet direct imaging with ELT-PCS

Ryan Griffiths, Siddharth Maharana and Matthias Tecza

A key science goal for the Planetary Camera and Spectrograph (ELT-PCS) instrument is to image rocky exoplanets in reflected light around nearby M- and K-dwarfs. These observations will require a contrast of 10^(-9) at 100 mas angular separation, and 10^(-8) at 10 mas. To achieve such an extreme performance, every instrument design choice must be carefully evaluated. For ELT-PCS's science instruments, perhaps the most critical design choice is which integral field unit (IFU) technology to use. To this end, we have developed a modular, lab-based integral field spectrograph test bench with which to compare the performance of two popular IFU technologies: image slicers and lenslet arrays. The test bench implements a Lyot coronagraph and a spatial light modulator to simulate a high-contrast imaging system, which feeds each IFU with a diffraction-limited PSF image. Each IFU is coupled to the spectrograph, which achieves R ~ 3000 with the image slicer and R ~ 100 with the lenslet array. The calibration and data reduction for each IFU design are described and the initial results of a contrast comparison are presented. The lenslet array achieves a deeper contrast at angular separations of less than 6 lambda/D. The image slicer, however, gains more at small separations from applying spectral deconvolution, with a 3.4x greater gain at 4 lambda/D. Spectral deconvolution further yields a contrast curve close to the detector noise floor. Further work will focus on carrying out a fully-controlled characterisation of the lenslet array IFU and a more comprehensive study into the effects of adaptive optics residuals on the contrast.
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Statistical Mechanics

Superfluid helium

Charles Radin

We are interested in modelling superfluid helium-4, the common isotope of helium, of atomic number 4. We present a mathematically solvable toy model of the phase transition between the normal liquid and superfluid phases and use it to show how an order parameter can be obtained for the superfluid.
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Solar and Stellar Astrophysics

Revisiting BV & BW Draconis: Detailed Study of Intriguing Multiple System

J. J. Tokarek, W. Dimitrov, M. Polińska et al. (+6 more)

The BV & BW Draconis system is a unique coplanar system of two eclipsing contact binaries. The main objective of this study is to develop a model based on new observations. The only model of the system was obtained 40 years ago. New photometric and spectroscopic data have been collected. Brightness measurements were performed using the differential aperture photometry method, while radial velocity measurements were performed using the cross-correlation method. The resulting curves were analyzed using the Wilson-Devinney method. The resulting model is similar to the one obtained previously; however, the masses of the four components are higher, and the differences are outside the margin of error. In the case of BW Dra, the photometric data indicate the presence of a spot on the star's surface. Based on our spectroscopic and photometric data, the latest measurements of eclipse times have been obtained. These results, together with other new measurements, confirm previous findings: both pairs exhibit eclipse time variability. In the case of BV Dra, the parabolic and sinusoidal trends were confirmed and refined. For the second pair, BW Dra, a change in behavior was observed that may be related to a change in period.
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All authors J. J. Tokarek, W. Dimitrov, M. Polińska, M. K. Kamińska, K. Kamiński, P. Koleńczuk, J. Pietrucha, Sz. Ptak, M. Witczak

Instrumentation and Methods for Astrophysics

Comparative analysis of fiber Bragg grating filter losses inscribed by continuous wave UV and femtosecond-IR lasers for astrophotonics

Aashia Rahman, Ria G. Krämer, Abani Shankar Nayak et al. (+8 more)

Fiber Bragg grating (FBG) filters have been demonstrated as promising components in astrophotonic instrumentation for near-infrared ground-based observations. Given the photon-starved nature of astronomical applications, it is critical to minimize insertion losses across astrophotonic components. In addition to the insertion loss (IL) introduced by specialty fibers and inscription techniques, FBGs exhibit cladding mode (CM) losses. In this work, we studied the loss characteristics of five filter lines in three photosensitive fibers, i.e., a low-numerical-aperture (NA) fiber, a high-NA bend-insensitive fiber, and a cladding-mode-suppressed (CMS) fiber, and in a non-photosensitive fiber, SMF-28. The filters were inscribed using two phase mask-based illumination methods: a continuous wave ultraviolet (UV) laser with a complex phase mask allowing for multi-channel filters, and a femtosecond infrared (fs-IR) laser with phase mask integrated shaping apertures for spectral profile control. Our results show that UV-inscribed gratings in high-NA bend-insensitive fiber yield the lowest CM losses ($\approx$ 0.5 dB) among photosensitive fibers, but exhibit the highest IL (4.6 dB), and FBGs in non-photosensitive SMF-28 fiber, inscribed with fs-IR, achieve the lowest IL (< 0.05 dB) with a comparatively higher CM loss (0.93 dB). To reduce the high IL in high-NA fiber, we explored tapering and bridging methods and report that bridging reduces IL by $\sim$ 3 dB. We show that both filter platforms remain viable for integration into an astrophotonic system, with IL below 1 dB. Finally, we propose a compact bridge-fiber scheme with the potential to further reduce IL to below 0.5 dB while reducing the number of bridging fibers and, consequently, the number of splice junctions by 50%.
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All authors Aashia Rahman, Ria G. Krämer, Abani Shankar Nayak, Julius Göhring, Piyamas Choochalerm, Anna Maria Weiß, Samuel L. Döpfner, Tim Schleifer, Kalaga Madhav, Martin M. Roth, Stefan Nolte

Optics

Overcoming Scattering in High-Cell-Density Tomographic Volumetric Bioprinting Using Computational Light Optimization

Qianyi Zhang, Felix Wechsler, Viola Sgarminato et al. (+2 more)

Tomographic volumetric additive manufacturing has emerged as a transformative 3D printing technology for rapidly fabricating complex geometries. It offers significant advantages for bioprinting due to its contactless and short process time (a few tens of seconds). However, the presence of high cell densities ($>10^7$ cells mL-1) in bioresins introduces substantial light scattering, which degrades printing resolution and fidelity, hindering the fabrication of biologically relevant microstructures such as vascular channels and cavities. To address this challenge, we utilize a computational patterning framework leveraging physically based inverse rendering to optimize light delivery in scattering environments. This method iteratively refines tomographic projections by simulating light-matter interactions in cell-laden hydrogels, enabling precise compensation for scattering effects. Experimental results demonstrate that our approach achieves 500 ${\mu}m$ diameter vascular channels at $2*10^7$ cells mL-1. Furthermore, we integrate this computational method with refractive index matching strategies, reducing scattering artifacts by minimizing optical mismatch between cells and the hydrogel matrix, enabling printing at $4.1*10^7$ cells mL-1. The compatibility of these dual strategies enables unprecedented print fidelity in turbid bioresins. This advancement expands the scope of tomographic volumetric additive manufacturing for engineering functional tissues with intricate microarchitectures.
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All authors Qianyi Zhang, Felix Wechsler, Viola Sgarminato, Christophe Moser, Riccardo Rizzo

Fluid Dynamics

Confinement-induced evolution and breakup of viscoelastic filaments in microfluidic coflows

U. K. Kar, T. Sujith, D. Ghosh et al. (+1 more)

Viscoelastic filament thinning is classically described by elastocapillary dynamics in extensional flows, yet in confined microchannels the combined effects of wall-induced shear, elasticity, and capillarity remain poorly understood. Here, we experimentally investigate the breakup of a shear-thinning viscoelastic liquid coflowing with an immiscible Newtonian fluid in a rectangular microchannel, focusing on the formation, stretching, instability, and breakup of the thin filament connecting the primary droplet to the upstream liquid. Four regimes: stable coflow, squeezing, dripping, and jetting are identified and mapped using the capillary numbers of the dispersed and continuous phases and an elastocapillary parameter. Although elasticity weakly affects the onset of primary droplet formation, it strongly alters later filament dynamics by delaying capillary breakup and stabilising long-lived filaments. Scaling analyses based on capillary, viscous, and elastic force balances predict the primary droplet size, critical filament thickness at instability onset, maximum filament length, and critical jet length. Particle tracking shows that confinement creates a non-uniform wall-induced shear field along the inclined filament, producing spatial variations in interfacial velocity and initiating the first bead-on-a-string instability at the location of maximum shear. A Rayleigh-Plateau analysis incorporating an effective viscosity derived from the Oldroyd-B model predicts the instability wavelength and growth rate to the correct order of magnitude. These results show that confined viscoelastic breakup is governed not solely by classical elastocapillary thinning, but by a coupled wall-shear-elasticity mechanism controlling filament stretching, instability, and secondary droplet formation, thereby providing a predictive framework for filament-mediated breakup in confined viscoelastic multiphase flows.
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All authors U. K. Kar, T. Sujith, D. Ghosh, A. K. Sen

Mathematical Physics

Transparent boundary conditions for the spatially discrete Schrödinger equation: Reflectionless quantum transport in 1D lattices

Mashrab E. Akramov, Jambul R. Yusupov, Matthias Ehrhardt et al. (+1 more)

We construct exact transparent boundary conditions (TBCs) for a time-continuous, spatially discrete Schrödinger equation that models a one-dimensional quantum lattice. Using a recently developed exact solution for the discrete system, we derive the Dirichlet-to-Neumann maps analytically via Laplace transforms. This yields a convolution-type boundary condition governed by Bessel functions. We rigorously demonstrate the consistency of this discrete formulation with its continuous counterpart in the continuum limit. Additionally, we present an efficient time-discretization scheme based on the trapezoidal rule for practical implementation. Numerical experiments using a Crank-Nicolson solver verify that our proposed TBCs eliminate spurious backscattering entirely and preserve reflectionless propagation of a Gaussian wave packet exiting the computational domain
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All authors Mashrab E. Akramov, Jambul R. Yusupov, Matthias Ehrhardt, Davron U. Matrasulov

Chemical Physics

Physics-Based Molecular Fingerprints from Spectral Graph Theory Provide Efficient Geometry-Aware Measures of Chemical Similarity

Jacob W. Toney, Ayleen Y. Farnood, Samir Darouich et al. (+1 more)

Molecular representations are essential for the evaluation of molecular similarity and the development of structure-property relationships. Despite the known importance of 3D structure to determine chemical and physical properties, the most widely used molecular fingerprints encode only two-dimensional connectivity. Such representations fail to distinguish similar but distinct stereoisomers and conformers. Alternative 3D methods are typically defined pairwise, making their application to large chemical spaces prohibitive, while deep learning embeddings are expressive but uninterpretable and limited by their training data diversity. Here, we introduce novel physics-inspired molecular fingerprints based on principles from spectral graph theory. We represent molecules as a complete graph in 3D space, with edge weights encoding heuristic physical interactions. Eigenvalue decomposition of the resulting graph Laplacian matrix results in a computationally efficient fixed-length chemical fingerprint that encodes 3D structure while obeying necessary physical symmetries of permutation and E(3) invariance. Spectral fingerprints differentiate between unique molecular structures with identical 2D connectivity, overcoming a limitation of 2D descriptors, while maintaining the low computational cost needed for efficient screening of vast chemical spaces. We evaluate our fingerprints with community detection algorithms and observe strong performance against representative baselines across datasets from organic, inorganic, biological, reticular, and reaction chemistry. Nearest-neighbor property estimation and applicability domain analyses reveal the utility of our molecular representation in machine learning and cheminformatics. We anticipate that spectral fingerprints will serve as generalizable, interpretable, and efficient measures of chemical similarity that incorporate 3D information at minimal cost.
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All authors Jacob W. Toney, Ayleen Y. Farnood, Samir Darouich, Heather J. Kulik

High Energy Physics (Phenomenology)

Photon-nucleon entanglement in Compton scattering at low and high energies

Yoshitaka Hatta and Víctor Martínez-Fernández

We study spin-spin entanglement in the final state photon-nucleon system in Compton scattering, both at low energy below the pion threshold and at high energy in perturbative QCD to next-to-leading order. We first establish a no-go theorem showing that, for any spin-$\frac{1}{2}$ target, entanglement cannot be generated in unpolarized Compton scattering if the scattering amplitudes are real. We then consider polarized Compton scattering off the electron, the proton and the neutron. At low energy, we uncover a rich variety of maximally entangled Bell states and their unitary equivalents realized across different regions of the kinematic plane. Interestingly, the proton and neutron targets exhibit distinct patterns of entanglement. In the neutron case, the electric and magnetic polarizabilities dramatically influence the pattern and even the existence of entanglement. This suggests that entanglement can serve as a novel tool for investigating the detailed electromagnetic properties of the nucleons.
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Solar and Stellar Astrophysics

White Dwarf Stellar Structure from Effective Polymer Geometry in Loop Quantum Gravity

Edson Otoniel, Jonathan A. Rebouças, M. C. Araújo et al. (+1 more)

We construct an effective Tolman Oppenheimer Volkoff system for cold carbon white dwarfs using the areal radius form of a polymer metric sector motivated by loop quantum gravity. The two asymptotic mass parameters of the geometry are retained in the stellar prescription through $M_B\rightarrow m(R)$ and $M_W=\eta m(R)$, while the polymer amplitude is controlled by $A_\lambda$. The matter sector is kept fixed and is described by the Chandrasekhar equation of state and by the same carbon model with the Coulomb lattice correction. The resulting equations recover the general relativistic TOV system and the symmetric polymer limit. For the undeformed sequences we obtain $M_{\max}=1.4166\,M_\odot$ for the Chandrasekhar model and $M_{\max}=1.3850\,M_\odot$ when the lattice correction is included. Turning on $A_\lambda$ shifts the massive part of the equilibrium sequence upward without stiffening the equation of state, reaching $M_{\max}=1.7125\,M_\odot$ and $1.6907\,M_\odot$ at $A_\lambda=100$ for the two matter models. These configurations remain within the matter domain imposed by the inverse beta decay boundary used in the scan. The asymmetric ratio $\eta=M_W/M_B$ changes the metric function near the polymer transition region, but its effect on white dwarf observables is small: across the selected configurations, $M_{\max}$ changes by less than $0.1\%$ and the corresponding radius by less than $0.33\%$. The calculation therefore identifies $A_\lambda$ as the parameter controlling the super Chandrasekhar displacement of the mass radius relation, while $\eta$ acts mainly as a geometric asymmetry parameter in the low compactness regime probed by white dwarfs.
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All authors Edson Otoniel, Jonathan A. Rebouças, M. C. Araújo, J. Furtado

Astrophysics of Galaxies

Scylla: Observational Evidence for an Order of Magnitude in Dust Mass Opacity Evolution with ISM Density in the Large Magellanic Cloud

Christina W. Lindberg, Christopher J. R. Clark, Claire E. Murray et al. (+11 more)

The emissivity of dust is known to vary greatly with radiative environment, density, grain chemistry, and geometry. Discrepancies between dust mass surface densities derived from far-infrared (FIR) emission and visible extinction persist across and within galaxies in the local Universe. Here, we use new extinction and emission measurements towards the LMC to show that this discrepancy is driven by the dust mass opacity evolving with the intrinsic density of the ISM, and that the ratio between FIR and optical dust mass opacity varies with gas surface density. These new findings imply that the dust mass opacity in the FIR could increase by nearly an order of magnitude (e.g., $\kappa_{160} = 0.3 - 6\ m^2\ kg^{-2}$) across over an order of magnitude of total hydrogen surface density $(\Sigma_H = 4 - 100 M_{\odot}\ pc^{-2})$, corroborating previous theoretical models for dust mass opacity evolution in the FIR, and providing new implications for emission-based dust mass estimates.
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All authors Christina W. Lindberg, Christopher J. R. Clark, Claire E. Murray, Julia Roman-Duval, Caroline Bot, Yumi Choi, Roger E. Cohen, Steven R. Goldman, Karl D. Gordon, Kristen B. W. McQuinn, Elizabeth Tarantino, Benjamin F. Williams, Petia Yanchulova Merica-Jones, Catherine Zucker

High Energy Physics (Theory)

Interacting Galilean and Finite-Energy Carroll Fermions

Pulastya Parekh, Aditya Sharma and Mauricio Valenzuela

We present a unified derivation of the Galilean and Carrollian limits of the massive Dirac action based on a similarity transformation depending on the mass and the speed of light. The two choices of Dirac conjugation, combined with different mass scalings, generate distinct families of limiting actions. This construction recovers known Galilei and Carroll fermion models and yields new systems, one in each regime. We classify a sufficient set of boost-compatible local (self-)interactions, which includes Nambu–Jona-Lasinio (NJL). The new Galilean free action possesses a local fermionic gauge symmetry that eliminates its local field content. A selected quartic interaction, preserving the Bargmann boost, explicitly breaks the original fermionic gauge symmetry so that the argument that eliminates the field content no longer applies. The NJL limit interaction merely deforms the realization of that gauge symmetry. We show that the energy parameter in several Carroll actions can be eliminated by a time-dependent phase redefinition; conversely, in the new Carrollian extension the energy cannot be removed.
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High Energy Physics (Experiment)

Search for resonant production of lepton-enriched semivisible jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV

CMS Collaboration

This search targets the resonant production of lepton-enriched semivisible jets (SVJs) from a strongly coupled dark sector, using 138 fb$^{-1}$ of proton-proton collision data collected with the CMS detector at the CERN LHC at $\sqrt{s}$ = 13 TeV. Two scenarios are investigated: jets enriched in all lepton flavors (SVJ$\ell$ signature) and jets predominantly enriched in tau leptons (SVJ$\tau$ signature). The analysis focuses on final states in which the missing transverse momentum is aligned with jets containing nonisolated leptons. A dual machine-learning strategy is employed, using a graph neural network for jet identification and a fully connected neural network that combines jet- and event-level information to enhance signal sensitivity and background estimation. The signal models assume a heavy Z' mediator with a benchmark coupling of 0.25 to standard model quarks, together with prompt decays of unstable dark hadrons. In the SVJ$\ell$ scenario, mediator masses up to 4.7 TeV are excluded at 95% confidence level, while masses between 1.8 and 3.5 TeV are excluded in the SVJ$\tau$ scenario. These results provide the first experimental constraints on lepton-enriched semivisible jets.
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High Energy Physics (Phenomenology)

Beyond Borel Windows: A Systematic Optimization Framework for QCD Sum Rules

Raphael M. Albuquerque

We propose a systematic optimization framework for determining the sum rule window in QCD Laplace sum rules. Instead of relying primarily on fixed convergence percentages and visual plateau selection, the procedure combines an OPE entropy criterion, local mass stationarity, and a correlated analysis of the Laplace parameter $\tau$, the continuum threshold $t_c$, and the interpolating-current mixing angle $\theta$. The normalized OPE entropy is introduced to quantify the redistribution of the QCD contributions between the perturbative and nonperturbative sectors and to delimit an initial Working Region. This domain is subsequently refined by minimizing the residual variation of the mass estimator and requiring weak sensitivity to the continuum threshold and to the current composition. As an application, we study the lowest fully charmed tetraquark state with quantum numbers $J^{PC}=2^{++}$ using a mixed diquark–antidiquark and meson–meson interpolating current. The optimization selects $\theta=17.2^\circ\pm0.4^\circ$, $\sqrt{t_c}=7.08\pm0.08~\mathrm{GeV}$, and $\tau=0.410\pm0.010~\mathrm{GeV}^{-2}$, leading to the mass prediction $M_{c\bar c c\bar c}^{2^{++}}=(6.32\pm0.11)~\mathrm{GeV}$. The predicted state lies in the near-threshold region of the di-$J/\psi$ spectrum and is compatible, within uncertainties, with the lowest resonant component reported by ATLAS and with the enhancement parametrized as $BW_0$ in the recent CMS publication. The proposed framework provides a reproducible way of identifying finite domains of reduced auxiliary-parameter sensitivity and of incorporating the remaining dependence into the final uncertainty.
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