Peer Revenue Returns subject to peer review

Papers

Fresh from arXiv, typeset properly. Highlighted words trade on the market.

Physics

Watch Physics

Wednesday 24 June

Quantum Physics

Quantum Detectability in Invisibility Cloaks

Mohammad Mehdi Sadeghi

Classical invisibility cloaks are designed to suppress selected scattering signatures and thereby make an object appear absent to external electromagnetic probes. However, the suppression of a classical scattering observable does not, by itself, establish that all information about the concealed object has been removed from the detected quantum state of light. Here we formulate the detectability of classically cloaked objects as a quantum-state distinguishability problem. Treating a linear passive cloak as an effective Gaussian quantum channel acting on the accessible detected modes, we show that local quantum undetectability requires the detected first and second moments to be independent of the hidden-object parameter. In this framework, quantum Fisher information provides an operational criterion for whether the concealed parameter remains estimable from the detected output state. We derive displacement- and covariance-level detectability conditions and show that a nonzero parameter imprint surviving in the detected Gaussian state leads to a nonzero accessible quantum Fisher information. To connect the criterion with a physical cloaking model, we analyze a regularized cylindrical transformation-optical cloak in the Born limit and compare the scaling of the classical scattering response with the derivative-based quantum sensitivity. The analysis shows that reducing a scattering amplitude is not equivalent to eliminating local quantum-state sensitivity. Loss, environmental noise, and finite numerical aperture degrade the accessible information, but quantum undetectability is reached only when the parameter imprint is removed from the detected state or projected entirely outside the accessible subspace. These results provide a Gaussian-channel framework for assessing when classical cloaking does, and does not, imply quantum-state undetectability.
Read the full abstract

Instrumentation and Methods for Astrophysics

VLT Beyond 2030 and Call for White Papers

Céline Péroux, Antoine Mérand and Martyna Chruślińska

The VLT Beyond 2030 conference gathered participants from the community and ESO experts to present and discuss science and technological ideas for the future of both the Very Large Telescope (VLT) and its interferometer (VLTI). An effort was made to pair participants with science and engineering backgrounds so as to optimise cross-field fertilisation and initiate 'out-of-the-main-room' discussions. The well-attended conference reflected the continued interest within our community in developing new projects for the VLT/I and the will to use this facility to answer key science questions that are likely to be crucial in the decades to come. This article presents a summary of the overall points of focus during the conference and also serves as the opening of the call for White Papers with a deadline of 15 January 2027. Proposers are encouraged to fast-forward to the years beyond 2030 to identify essential areas of research so that together we can shape a long-term roadmap for the VLT/I.
Read the full abstract

Accelerator Physics

Features of long particle beam self-modulated in plasma

Vlada Yarygova and Konstantin Lotov

Under certain conditions, a long particle beam self-modulates in a dense plasma, that is, it breaks down into a train of short, stable microbunches under the influence of its own wakefield. During this process, the beam also changes its radial profile: initially having a Gaussian shape, it evolves to a highly peaked equilibrium state with a density singularity on the axis. This change makes individual beam slices several times more efficient at exciting the wakefield. We have developed an analytical iterative model describing the transverse equilibrium state of the microbunches, which is applicable to most beam cross-sections. The model is based either on the conservation of the transverse adiabatic invariant or on empirically established relationships in cases where adiabaticity is violated. It predicts the radial profiles of beam density and wakefield potential, as well as the particle distribution in the transverse phase space. The model is benchmarked against numerical simulations and demonstrates a high degree of accuracy. In addition to the full model, we present simplified engineering formulas based on elementary functions that bypass iterative procedures
Read the full abstract

Astrophysics of Galaxies

Optical constants of Ih, Ic, and amorphous H$_2$O ices in the THz and IR ranges

A.A. Gavdush, F. Ribeiro, M.K. Matveishina et al. (+9 more)

Direct measurements of optical constants in the THz spectral region for astrophysically relevant H$_2$O ice samples are scarce. Extrapolation of optical properties in the THz spectral region from IR data can introduce uncertainties into astrophysical models. We measured the optical properties of water ice samples in the Ih and Ic forms as well as amorphous solid water (ASW) in the THz region in order to derive broad optical constants using literature and experimental data in the THz-IR range. In our experiments, the Ih, Ic, and ASW ices were grown by vapour deposition onto a cold substrate and measured by THz pulsed spectroscopy. Their THz optical properties were retrieved, compared with the THz-IR literature data, and approximated using the multiple-Lorentz model. From the existing literature data on the Ih, Ic, and ASW ices, we selected samples with the highest optical constants and classified them as compact. Their optical properties were merged in the frequency range of $\nu = 0.3$-$120$~THz (the wavelength range of $\lambda = 1$~mm-2.5$~\mu$m). The underlying absorption bands were attributed to vibrational modes and approximated using the multiple-Lorentz model while accounting for anharmonicity. Discrepancies primarily arising in low-absorption regions between the experimental data and broadband models were attributed to factors such as the model's complexity and the baseline-subtraction procedure. The THz response of all ices is formed by the low-frequency wings of the IR bands and the single broad low-intense THz peak around $1.8$~THz, which is very similar for all phases. The opacity calculation for dust grains covered by H$_2$O ice mantles based on experimental data shows discrepancies with data derived by extrapolation. The inferred THz-IR optical constants of water ice are important for future observations and modelling of cold clouds and protoplanetary disks.
Read the full abstract

All authors A.A. Gavdush, F. Ribeiro, M.K. Matveishina, A.Vyjidak, F. Kruczkiewicz, G.A. Komandin, S.V. Garnov, K.I. Zaytsev, A.V. Ivlev, T. Grassi, B.M. Giuliano, P. Caselli

Statistical Mechanics

Lattice non-invertible symmetry from non-commuting transfer matrices

Eric Vernier, Yuan Miao and Masahito Yamazaki

Conventional quantum integrability is encoded in a commuting algebra of transfer matrices. By contrast, several models possess additional non-commuting conserved charges with important physical consequences, yet the nature of the corresponding symmetry has remained elusive. Focusing on the XXZ spin chain at roots of unity, we show that the non-Abelian analogue of the commuting transfer-matrix algebra is governed by quadratic relations following from a new class of unbalanced Yang–Baxter/RLL relations. This quadratic algebra is shown to encode precisely the Onsager algebra, for which we construct explicit matrix-product representations of both its generators and its duality defect line. The latter obeys $\mathbb{Z}_N$ Tambara–Yamagami fusion rules, thereby providing a lattice realization of the topological defect lines of the compactified boson conformal field theory. Our results identify non-Abelian transfer-matrix algebras as a microscopic origin for Onsager symmetry and dualities in lattice models.
Read the full abstract

Instrumentation and Detectors

First evaluation of the tracking performance of the ARCADIA Fully Depleted MAPS with high-energy proton beam

M. Rignanese, S. Ciarlantini, C. Pantouvakis et al. (+19 more)

This work presents test beam characterization of the ARCADIA Main Demonstrator 3, a 200 $\mu$m thick Fully Depleted MAPS developed using a custom LFoundry 110 nm CIS process on a high-resistivity substrate. Measurements using a 120 GeV proton beam demonstrate a detection efficiency exceeding 99% and a spatial resolution down to 3.8 $\mu$m. The study evaluates cluster size, spatial resolution, and efficiency as a function of the threshold and reverse bias voltage.
Read the full abstract

All authors M. Rignanese, S. Ciarlantini, C. Pantouvakis, A. Zingaretti, A. Apresyan, P. Azzi, N. Bacchetta, C. Bonini, D. Chiappara, D. Falchieri, S. Garbolino, A. Hayrapetyan, S. Mattiazzo, L. Pancheri, D. Pantano, A. Rivetti, M. Rolo, R. Santoro, R. Turrisi, J. Wyss, I. Zoi, P. Giubilato

High Energy Astrophysical Phenomena

A magnetically-supported disk-corona model for Changing-Look AGN transitions

Marios Kouzis, Agata Różańska, Debora Lančová et al. (+2 more)

Changing-Look Active Galactic Nuclei (CLAGN) undergo dramatic spectral and luminosity transitions on timescales of months to a few years – orders of magnitude shorter than the viscous timescale of a standard $\alpha$-disk at the radii where the optical/UV continuum is generated, for typical supermassive black hole masses. We show that a magnetically supported disk-corona model reproduces both the observed Eddington ratio at which changing event occurs and the observed transition duration. Using the diskvert code, which solves the steady vertical structure under simultaneous gas, radiation and magnetic pressure support with a self-consistent warm corona, we (i) construct thermal-viscous S-curves, and (ii) calculate the integrated thermal timescale together with the front propagation timescale. We compute a large grid of models of different black hole masses, Eddington ratios, magnetic viscosities, and disk radii, showing that magnetized disks push the S-curve knee down to an Eddington ratio of $ \approx 0.01-0.03$, and introduce a new stable branch of high luminosity solutions, while the limit-cycle timescale enters the months-to-years range for $M_\mathrm{BH} = 10^{7}-10^{9}\,\mathrm{M_\odot}$. Confronted with a sample of five CLAGN (Mkn 590, NGC 1566, IRAS 23226$-$3843, Mkn 1018, NGC 2617), the model jointly reproduces the empirical Eddington rates and the observed event durations only when the inner disk is strongly magnetized. The case of Mkn 590 is especially constraining: the recent tightly-determined transition Eddington ratio is matched by a highly magnetized disk-corona flow at small radii.
Read the full abstract

All authors Marios Kouzis, Agata Różańska, Debora Lančová, Bożena Czerny, Dominik Gronkiewicz

Quantum Physics

Long-lasting Topological Entanglement in a Monitored Rashba Nanowire

Emanuele Guida, Giulia Salatino, Gianluca Passarelli et al. (+2 more)

We study the topological properties of a monitored Rashba chain along quantum-jump trajectories, investigating the persistence of the initial topological value of the disconnected entanglement entropy (DEE). We find that the DEE persists in its topological value for a time linear in the system size, even if the dissipation acts on the boundary and affects the topological Majorana modes. The reason for this phenomenon lies in the absence of particle conservation and in the degeneracy of the topological manifold, allowing the monitoring to let the system switch between different topological states – alternatively creating and annihilating a Majorana mode – while producing a poisoning of finite-energy ballistically propagating quasiparticles that eventually destroy the topological entanglement structure.
Read the full abstract

All authors Emanuele Guida, Giulia Salatino, Gianluca Passarelli, Angelo Russomanno, Procolo Lucignano

Quantum Physics

Spin-Momentum Impedance and Filtering by a Spin-Coupled Absorbing Boundary Condition

Alireza Jozani

Absorbing boundaries are often treated as scalar sinks. Here we show that a spin-coupled absorbing boundary for a Pauli particle acts instead as a spin–momentum impedance. Its tangential boundary symbol has two branches, $i\kappa\pm|\boldsymbol{\xi}|$, coupling normal absorption to in-plane momentum. In a harmonic guide, the transverse ground state samples $|\boldsymbol{\xi}|\sim \ell_\perp^{-1}\sim\sqrt{\omega}$; narrowing the guide therefore strengthens a local evanescent boundary response without introducing a bulk potential barrier. Solving the detector-present spinor absorbing-boundary evolution, we identify boundary-induced filtering: the prompt detector flux is suppressed, the fixed-window detected fraction is reduced, and a delayed oscillatory sector appears. Over that window the restricted mean detection time is fitted by $A+B\sqrt{\omega}$, with setup-dependent coefficients. The robust result is a spin–momentum filtering mechanism with boundary scale $|\boldsymbol{\xi}|\sim\sqrt{\omega}$, not a universal arrival-time law.
Read the full abstract

Solar and Stellar Astrophysics

Long-term Orbital Period Variations of the Eclipsing Dwarf Nova HT Cas

Aykut Ozdonmez, Huseyin Er, Ilham Nasiroglu et al. (+7 more)

We present a comprehensive analysis of the long-term orbital period variations in the short-period eclipsing dwarf nova HT Cas. By combining our new high-precision mid-eclipse times obtained between 2015 and 2026 with archival data, we constructed an updated $O-C$ diagram spanning a $\sim$48-years. Statistical analysis confirms outbursts do not cause systematic phase shifts, validating the use of all activity states. Through MCMC modeling, we show that the $O-C$ variations require a two-companion configuration. A free-eccentricity LTT model captures the variations but yields unconstrained posteriors and a highly eccentric outer orbit ($e_3 \sim 0.94$) that instantly collapses in N-body dynamical simulations. Imposing a circular constraint ($e=0$) resolves these mathematical degeneracies, yielding well-constrained posterior distributions. This dynamically stable model identifies two hypothetical circumbinary companions with minimum masses of $\sim 9.8 M_{Jup}$ and $\sim 5.0 M_{Jup}$, and periods of $\sim 32.6$ and $\sim 15.1$ years. Besides, this configuration inherently produces a negative quadratic term ($Q = -1.23 \times 10^{-14}$ days), aligning with secular period decrease predicted by standard CV evolution theory below the period gap. Refined energy-budget tests reveal that classical Applegate mechanisms require significantly more energy than the secondary star provides, indicating they cannot independently drive the modulations. While advanced magnetic frameworks may offer theoretical alternatives, our findings demonstrate that a dynamically stable two-companion architecture provides a highly robust and physically viable explanation, consistent with second-generation planet formation within a post-common-envelope disk.
Read the full abstract

All authors Aykut Ozdonmez, Huseyin Er, Ilham Nasiroglu, M. Emir Kenger, Murat Tekkesinoglu, Ergun Ege, Burak Batuhan Gürbulak, Ali Takey, Nazl{\i} Karaman, M. Abdelkareem

Quantum Physics

Towards Robust Optimal Measurements Against Noise in Quantum Metrology

Xinglei Yu, Xinzhi Zhao, Liangsheng Li et al. (+4 more)

Quantum parameter estimation utilizes quantum mechanical effects to attain higher measurement precision than classical schemes. In practical implementations, however, noise is inevitably present during the measurement process, causing a decrease in precision. Quantifying the impact of noise on different measurements is of considerable significance. Here, we experimentally investigate robust optimal measurements based on the theory of Fisher information measurement noise susceptibility (FI MENOS), which quantifies how susceptible a measurement is to noise. By constructing a polarizing Mach-Zehnder interferometer, we implement phase estimation under controlled noise. Our results indicate that different measurements exhibit distinct sensitivities to noise. To assess the influence of diverse noise types on precision, we further construct an experimental setup capable of introducing various forms of noise. The experimental results affirm that FI MENOS represents the worst-case scenario for estimation precision, enabling us to evaluate the noise immunity of optimal measurements. Our work provides a deeper insight into quantum metrology with noise, marking a notable advancement in quantifying the robustness of quantum estimation schemes against measurement noise effects.
Read the full abstract

All authors Xinglei Yu, Xinzhi Zhao, Liangsheng Li, Stanisław Kurdziałek, Chengjie Zhang, Chuan-Feng Li, Guang-Can Guo

Instrumentation and Methods for Astrophysics

A Wideband Millimeter-wave Receiver at 210-350 GHz for LMT-FINER

Haoran Kang, Takafumi Kojima, Takeshi Sakai et al. (+9 more)

The Far-Infrared Nebular Emission Receiver (FINER) project is developing two wideband dual-polarization sideband-separating receivers covering 120-210 GHz and 210-350 GHz to efficiently identify high-redshift galaxy candidates in the early universe. Based on high-critical-current-density superconductor-insulator-superconductor mixer technology originally developed for the ALMA wideband sensitivity upgrade, the FINER receivers are designed to provide an intermediate-frequency bandwidth of 3-21 GHz per sideband and per polarization, approximately five times wider than the current ALMA specifications. After installation on the Large Millimeter Telescope, these receivers are expected to offer highly efficient spectral-scanning capability among (sub)millimeterwave facilities in the northern-hemisphere. This paper reports the initial laboratory characterization of the 210-350 GHz receiver. The measured single sideband receiver noise temperature is approximately 100 K over most of the radio-frequency band. Digital sideband separation was also demonstrated using a wideband spectrometer array (DRS4), achieving an image rejection ratio of around 20 dB in the initial tests. These results represent an important step toward the realization of a wideband spectral-scanning receiver system for FINER.
Read the full abstract

All authors Haoran Kang, Takafumi Kojima, Takeshi Sakai, Yoichi Tamura, Shun Ishii, Akio Taniguchi, Masato Hagimoto, Masato Kato, Taku Nakajima, Tai Oshima, Sho Masui, Issei Watanabe

High Energy Astrophysical Phenomena

Observation of A Solar Like Magnetic Reconnection Event in an AGN Corona with XRISM

Gal Vardi, Ehud Behar, Liyi Gu et al. (+14 more)

The X-ray source in AGN is commonly referred to as the corona by analogy to stellar coronae. The similarities between the two suggest that the heating mechanism of AGN coronae is magnetic reconnection – as in cool stars – but this has not yet been directly observed. This work presents the first observational evidence for a magnetic reconnection flare in an AGN corona. We report on a flare in NGC 3783, which was observed with XRISM/Xtend and XMM-Newton/EPIC-PN exhibiting distinct temporal evolution in soft ($<2.0\,$keV) and hard ($>2.0\,$keV) X-rays. An Ultra-Fast Outflow (UFO) was detected during the event. The flare features the Neupert effect – a temporal signature of the hard light curve correlating with the time derivative of the soft light curve, which shows that the flare is powered by magnetic reconnection, The Neupert effect is widely observed in the Sun, with Coronal Mass Ejections (CMEs) playing a role analogous to the UFO. We derive an upper limit of $30 \, R_g$ on the height of the magnetic loop from which the flare originates. Using the UFO's measured properties to characterize the magnetic field, we obtain $B > 1.3 \times 10^4\,$G for the field annihilated during the flare from total energy considerations, and $B \approx 500\,$G for the momentary magnetic field during reconnection from a dynamical consideration.
Read the full abstract

All authors Gal Vardi, Ehud Behar, Liyi Gu, Jelle Kaastra, Matteo Guainazzi, Missagh Mehdipour, Keigo Fukumura, Jon Miller, Ari Laor, Erin Kara, Megan E. Eckart, Misaki Mizumoto, Christos Panagiotou, Chen Li, Ogawa Shoji, Matilde Signorini, Keqin Zhao

Quantum Physics

Anomalous topological superradiant phases

You-Qi Lu, Yu-Yu Zhang and Zi-Xiang Hu

We present a novel set of light-matter topology realized by implementing a finite-component quantum Rabi array with a photonic analog of the Su-Schrieffer-Heeger (SSH) configuration. We demonstrate how complex light-matter couplings with species-dependent phases lead to the closure of superradiance-induced band gap in a manner that differs from that in the SSH model. We uncover an topological superradiant phase transition from a normal phase to a topological superradiant electromagnet phase, which is characterized both by a local order parameter and a global topological invariant. Novel superradiance-enhanced edge states emerge with significantly amplified excitations superior to those in topological normal phase. Strikingly, tuning light-atom coupling induces novel topological superradiant electric and magnetic phases, exhibiting chiral edge-mode excitation at opposite boundaries. Our proposed setup offers a tunable platform for topological quantum optics, advancing applications in topological superradiant lasers.
Read the full abstract

Instrumentation and Methods for Astrophysics

A Non-Negativity Iterative Approach to Image Deconvolution for SKA

Le Zhang and Shiyu Li

We introduce a novel algorithm for image deconvolution applicable to interferometric radio observations, based on the assumption of non-negative source fluxes. The method enables rapid and efficient image reconstruction in an iterative manner, without requiring prior knowledge or training. Its computational cost scales linearly with the number of pixels: for example, a $512\times 512$ image can be processed in about 1-2 seconds on a standard laptop. We validate the algorithm using both point sources and an extended galaxy image, incorporating a realistic SKA-Low PSF with incomplete $uv$-coverage, though tests are conducted in noise-free simulations. Comparison with the CLEAN method demonstrates that our approach yields a good reconstruction, showing particular promise for the SKA and VLBI observations with sparse $uv$-coverage.
Read the full abstract

Instrumentation and Methods for Astrophysics

Application of Bayesian Statistical Tools to SKA Telescopes Polarization Surveys to Study Magnetization of the Large-scale Structure of the Universe

Valentina Vacca, Sebastian Hutschenreuter, Andrea Cabriolu et al. (+18 more)

Understanding cosmological magnetic fields requires a detailed knowledge of magnetism in the different environments of the large-scale structure of the Universe. Magnetic fields are well known to inhabit galaxy clusters, and recently their presence has been detected between galaxy clusters, along filaments extending up to 10-15 Mpc. Beyond that, there is limited information on the existence of magnetic fields in sheets and voids of the cosmic web. We propose a Bayesian statistical approach to study magnetic fields on large scales through observations of the Faraday rotation effect in large samples of polarized point-like background radio sources. We present the expectations to detect magnetization in environments of the large-scale structure with the SKA-Mid polarization survey planned by the SKAO Magnetism Science Working Group and with SKA-Low with AA4 telescopes, and discuss the required level of accuracy on the redshifts of the host galaxies for such a study. We find that about 50,000 mid-frequency Faraday rotation measurements complemented by high-precision redshifts are needed to constrain magnetization of dense environments as galaxy clusters. Investigation of magnetization in weakly-magnetized low-density enviroments, as filaments, will remain challenging, but low frequencies radio observations and spectroscopic redhifts for at least 17,000 will allow us to put first constraints.
Read the full abstract

All authors Valentina Vacca, Sebastian Hutschenreuter, Andrea Cabriolu, Torsten A. Ensslin, Philipp Frank, Jakob Roth, Martin Reinecke, Jens Jasche, Florent Leclercq, Ettore Carretti, Luigina Feretti, Chiara Ferrari, Federica Govoni, Cathy Horellou, Melanie Johnston-Hollitt, Francesca Loi, Matteo Murgia, Shane O'Sullivan, Rosita Paladino, Tessa Vernstrom, Gianni Fenu

Soft Condensed Matter

Bath-modes quantitatively capture the nonlinear microrheology of micellar solutions

Pierre Champagnac, Clemens Bechinger, Juliana Caspers et al. (+3 more)

Active microrheology experiments, in which a probe is driven through a complex fluid, often exhibit nonlinear responses that cannot be captured by generalized Langevin equations. Models that couple the probe to a Gaussian field reproduce such nonlinear effects qualitatively, but their large number of parameters hinders direct comparison with experiments. Here, we restrict these models to a small number of field modes and demonstrate that this reduced description quantitatively reproduces a broad range of active microrheology experiments in a micellar solution using a single set of parameters. We further show that the same framework extends naturally to multi-probe systems, such as colloidal dumbbells.
Read the full abstract

All authors Pierre Champagnac, Clemens Bechinger, Juliana Caspers, Pierre Illien, Matthias Krüger, Vincent Démery

Cosmology and Nongalactic Astrophysics

Euclid: Precise inference of defocus wavefront error from image diffraction spike measurements

D. Neumann, L. Miller, H. Hoekstra et al. (+146 more)

The success of the Euclid cosmological weak lensing measurements requires unprecedented knowledge of the point spread function (PSF) shape. Defocus wavefront errors induce variations in PSF size that directly bias inferred galaxy shapes. We present a rapid, model-independent estimator of the Euclid visible instrument defocus based on measuring subpixel shifts in diffraction spikes from bright stars, arising from the non-mirror-symmetric placement of the telescope spiders. This estimate requires no a-priori PSF model and can be directly inferred from individual survey exposures within seconds. We express defocus as the secondary mirror displacement along the optical axis, $\Delta z$, achieving a per-exposure precision of $\sigma(\Delta z) = 0.022\,\mu\text{m}$ in standard Euclid wide-survey images, corresponding to a peak-to-valley optical-path difference of $0.75\,\text{nm}$. This sensitivity resolves thermally induced shifts, typically 0.1-0.3$\,\mu\text{m}$, and enables tracking of temporal evolution and field-of-view variations when combining exposures within periods of stability. Since July 2024, the Euclid telescope has been exceptionally stable, while changes to defocus are effectively homogeneous across the field of view. By correlating defocus with PSF size, we find that the Euclid DR3 requirement of a fractional PSF size bias of $\left|\Delta R_\mathrm{PSF}^2/R_\mathrm{PSF}^2\right|<10^{-3}$ corresponds to field-averaged secondary mirror displacements exceeding $\langle \Delta z_\mathrm{thr}\rangle = (0.0683 \pm 0.0024)\,\mu\text{m}$. Our estimator provides a robust real-time monitoring tool, supplies a stringent prior for computationally intensive PSF model fitting, and is applicable not only to the Euclid telescope, but to other telescopes whose spider vanes are not mirror-symmetrically arranged.
Read the full abstract

All authors D. Neumann, L. Miller, H. Hoekstra, K. Kuijken, I. H. Whittam, N. E. Chisari, R. Nakajima, B. Altieri, A. Amara, S. Andreon, N. Auricchio, C. Baccigalupi, M. Baldi, S. Bardelli, A. Basset, P. Battaglia, A. Biviano, E. Branchini, M. Brescia, S. Camera, G. Cañas-Herrera, V. Capobianco, C. Carbone, J. Carretero, M. Castellano, G. Castignani, S. Cavuoti, K. C. Chambers, A. Cimatti, C. Colodro-Conde, G. Congedo, C. J. Conselice, L. Conversi, Y. Copin, F. Courbin, H. M. Courtois, M. Cropper, H. Degaudenzi, G. De Lucia, H. Dole, F. Dubath, X. Dupac, M. Farina, R. Farinelli, S. Farrens, S. Ferriol, S. Fotopoulou, N. Fourmanoit, M. Frailis, E. Franceschi, M. Fumana, S. Galeotta, K. George, B. Gillis, C. Giocoli, P. Gómez-Alvarez, J. Gracia-Carpio, A. Grazian, F. Grupp, S. V. H. Haugan, W. Holmes, F. Hormuth, A. Hornstrup, K. Jahnke, M. Jhabvala, B. Joachimi, S. Kermiche, A. Kiessling, M. Kilbinger, R. Kohley, B. Kubik, M. Kunz, H. Kurki-Suonio, R. Laureijs, A. M. C. Le Brun, S. Ligori, P. B. Lilje, V. Lindholm, I. Lloro, G. Mainetti, O. Mansutti, O. Marggraf, M. Martinelli, N. Martinet, F. Marulli, R. J. Massey, E. Medinaceli, S. Mei, M. Meneghetti, E. Merlin, G. Meylan, A. Mora, M. Moresco, C. Moretti, L. Moscardini, C. Neissner, R. C. Nichol, S.-M. Niemi, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, W. J. Percival, V. Pettorino, A. Pezzotta, S. Pires, G. Polenta, M. Poncet, L. A. Popa, G. D. Racca, F. Raison, A. Renzi, J. Rhodes, G. Riccio, E. Romelli, M. Roncarelli, R. Saglia, Z. Sakr, D. Sapone, B. Sartoris, M. Schirmer, P. Schneider, T. Schrabback, A. Secroun, E. Sihvola, P. Simon, C. Sirignano, G. Sirri, A. Spurio Mancini, L. Stanco, P. Tallada-Crespí, A. N. Taylor, I. Tereno, N. Tessore, S. Toft, R. Toledo-Moreo, F. Torradeflot, I. Tutusaus, L. Valenziano, J. Valiviita, T. Vassallo, A. Veropalumbo, Y. Wang, J. Weller, G. Zamorani, F. M. Zerbi, A. Gregorio, A. Loureiro, M. Sereno

Solar and Stellar Astrophysics

New Online Database of Symbiotic Variables: Catalog and Statistical Overview of Symbiotic Binaries

Jaroslav Merc, Rudolf Gális and Marek Wolf

We present the New Online Database of Symbiotic Variables (NODSV), a comprehensive and publicly accessible catalog of known and candidate symbiotic stars in the Milky Way and nearby galaxies. The database provides an up-to-date census of confirmed symbiotic binaries and systematically compiles information previously scattered across the literature, including photometric and spectroscopic properties, orbital parameters, and characteristics of both their cool and hot stellar components. It further records auxiliary diagnostics such as detected emission lines, flickering, X-ray emission, jets, or information about outburst activity. In its current release, NODSV contains nearly 1 400 objects, classified into confirmed symbiotic stars, three categories of candidates, and misidentified sources. Based on the collected data, though originating from heterogeneous studies, we present a statistical overview of the confirmed symbiotic population, highlighting the distributions of orbital parameters and the properties of the cool giants and their hot companions. Designed as a dynamic and evolving resource, NODSV provides a foundation for future observational campaigns and theoretical investigations of symbiotic binaries.
Read the full abstract

Disordered Systems and Neural Networks

Critical Universality of the SU (2) Gauge Glass Model Analyzed by the Dynamical Scaling Method

Yosei Takada, Yusuke Terasawa, Yuma Osada et al. (+1 more)

We investigate the critical phenomena of the three-dimensional (3D) $SU(2)$ gauge glass model, which can be regarded as the $O(4)$ spin-glass model with gauge symmetry. Using Monte Carlo simulations and the non-equilibrium relaxation method, we examine the critical behavior along phase boundaries across various degrees of disorder. Consistent with previous studies, we verify that weak disorder is irrelevant to the universality class; the critical behavior of the ferromagnetic-paramagnetic transition remains in the 3D $O(4)$ universality class of the pure ferromagnetic system. Additionally, we demonstrate that the paramagnetic-spin glass transition exhibits universal critical behavior independent of the disorder. Our findings provide valuable insights into the fundamental properties and universality of gauge glass models.
Read the full abstract

All authors Yosei Takada, Yusuke Terasawa, Yuma Osada, Yukiyasu Ozeki

Materials Science

Valence-change-driven reduction of antiphase boundaries in spinel ferrite epitaxial films

Kouki Takeo, Eiji Kita and Hideto Yanagihara

Antiphase boundaries (APBs) formed in thin films sometimes cause severe degradation of their physical properties. In particular, a high density of APBs in spinel ferrite films generates a non-negligible magnetic dead layer near the interface. In this study, we examined the effect of post-oxidation annealing in an oxygen plasma atmosphere on Co$_{0.125}$Fe$_{2.875}$O$_4$(001) thin films grown on MgO(001) as a model system. The thickness of the magnetic dead layer was found to be significantly reduced after post-oxidation, resulting in an increase in the saturation magnetization and an improved squareness ratio. Dark-field transmission electron microscopy analysis revealed that the post-oxidation process increased the antiphase domain size, indicating a substantial reduction in APB density. Furthermore, reflection high-energy electron diffraction and x-ray diffraction measurements confirmed that the spinel crystal structure and epitaxial strain were preserved after post-oxidation. These results suggest that post-oxidation proceeds through a topotactic solid-state reaction in which Fe$^{2.5+}$ ions are oxidized to Fe$^{3+}$, accompanied by cation rearrangement across APBs, thereby reducing APB density without degrading crystallinity and leading to improved magnetic properties in spinel ferrite epitaxial films.
Read the full abstract

Cosmology and Nongalactic Astrophysics

Study of Polarized Emission in Radio Halos and Filaments in the SKA Telescopes Era

Valentina Vacca, Federica Govoni, Matteo Murgia et al. (+12 more)

Synchrotron diffuse emission in merging galaxy clusters and along filaments connecting them demonstrates the presence of relativistic particles and magnetic fields in these environments. The study of the polarized signal associated with this emission represents a powerful tool to constrain the properties of intracluster magnetic fields and the physics of acceleration and transport of relativistic particles. Despite technological progress, detecting this polarized signal is still very challenging. In order to shed light on the capabilities of the SKA telescopes to study this emission, we use the data of cosmological magneto-hydro-dynamic simulations to predict the expected polarized surface brightness of diffuse synchrotron sources from the center of galaxy clusters to filaments of the cosmic web at 1.4 GHz. We explore the possibility to detect these sources with a polarization survey with SKA-Mid with AA4 telescopes and compare the results with those from pointed observations corresponding to longer exposure times. These simulations provide precious information to understand the potential of the SKA telescopes for studying the origin and evolution of cosmological magnetic fields. We discuss how these observations can be used in order to characterize the magnetic field and the distribution and energy content of the radio emitting plasma and to shed light on the link between non-thermal and thermal properties and the dynamical state of the system.
Read the full abstract

All authors Valentina Vacca, Federica Govoni, Matteo Murgia, Paolo Marchegiani, Hui Li, Myriam Gitti, Francesca Loi, Luigina Feretti, Ettore Carretti, Elia Battistelli, Andrea Cabriolu, Torsten A. Ensslin, Chiara Ferrari, Gabriele Giovannini, Richard A. Perley

High Energy Physics (Theory)

Holographic correlation functions of fermions in anisotropic plasma

Si-wen Li and Yan-qing Zhao

By using the gauge-gravity duality, we study the holographic fermionic correlation functions in strongly coupled anisotropic plasmas. Starting from the isotropic AdS-Schwarzschild black brane background, we revisit the prescription for computing the retarded Green's function of a probe Dirac fermion and then generalize the formulas with respect to the anisotropic geometries. The method is applied to three distinct holographic models that capture different physical origins of anisotropy: axion-induced, magnetic-field-induced and unquenched-flavor-induced. Numerical results for the holographic correlation functions reveal direction-dependent corrections, negative dips in the imaginary part, Landau levels in the fermionic dispersion (magnetic field), and a momentum-independent pseudogap indicating an incoherent metallic phase (flavors). Our results complement and go beyond the hard thermal loop approximation, providing non-perturbative insights into fermionic excitations in strongly coupled anisotropic plasmas relevant for heavy-ion collisions and certain condensed matter systems.
Read the full abstract

General Relativity and Quantum Cosmology

Times of arrival (TOA) of signals in the Kerr-MOG black hole

G. Y. Tuleganova, R. N. Izmailov, R. Kh. Karimov et al. (+2 more)

Modified gravity (MOG) theories are alternatives to general relativity (GR) that arose primarily from the need to explain the observed galactic flat rotation curves without invoking the elusive dark matter hypothesized by GR. A well known MOG is the Scalar-Tensor-Vector-Gravity (STVG) developed by Moffat, who has also found a spinning solution called the Kerr-MOG black hole (BH) characterized by the spin $a$ and MOG parameter $\alpha$, the latter determining the strength of the gravitational vector forces. We consider the static-MOG metric ($a=0$) to first understand how the nature of geometry drastically changes depending on different sectors of $\alpha $. Then we study the influence of $\alpha $ in each sector on a new astrophysical diagnostic caused by frame dragging, viz., the difference $\Delta t$ in the times of arrival (TOA) at the observer of signals emanating from a variable pulsar (PSR) passing behind a Kerr-MOG lens in a PSR-BH binary system. The study generalizes the zeroth order Laguna-Wolszczan formula up to third PPN order in $\left(1/r\right)$ using thin-lens approximation, which reveals how $\Delta t$ is influenced both by $a$ and $\alpha$. The magnitude and sign of $\alpha $ indicate deviations from GR ($\alpha =0$) and future measurements may constrain $\alpha$ provided a suitable binary is identified.
Read the full abstract

All authors G. Y. Tuleganova, R. N. Izmailov, R. Kh. Karimov, A. A. Potapov, K. K. Nandi

Instrumentation and Methods for Astrophysics

The Galaxy's Guide to the Tokenizer: A Benchmark for Scientific Foundation Models

Sogol Sanjaripour, Michael J. Smith, Manuel Pérez-Carrasco et al. (+3 more)

Tokenization is central to adapting scientific data for transformer-based foundation models, yet its impact on learned representations remains poorly understood. We compare four tokenization strategies, Affine, AIM, JetFormer, and VQ-VAE, within a unified transformer framework for astronomical imaging. Using 640,000 galaxy images from the DESI Legacy Survey and a shared AstroPT backbone, we evaluate each method on reconstruction fidelity and prediction of physical properties. Our results reveal trade-offs across approaches. The flow-based JetFormer achieves higher reconstruction quality, while VQ-VAE yields strong probe performance for galaxy physical properties. Affine and AIM better preserve localized morphological information. We find that reconstruction and representation quality are decoupled, and no single method consistently performs best across the tasks considered here. By grounding our evaluation in independently measured physical quantities, we hope this study serves to highlight the potential of scientific data as a basis for constructing interpretable benchmarks for foundation models.
Read the full abstract

All authors Sogol Sanjaripour, Michael J. Smith, Manuel Pérez-Carrasco, Juan Rafael Martínez-Galarza, Bahram Mobasher, Gabriela Canalizo

High Energy Astrophysical Phenomena

Probing Physical Conditions in Classical and Symbiotic Novae with the Square Kilometre Array Observatory

Rocco Lico, Marcello Giroletti, Arnau Aguasca-Cabot et al. (+9 more)

Cataclysmic variables and symbiotic stars are interacting binary systems in which a hot white dwarf (WD) orbits a companion main-sequence or red giant star, respectively. Accumulation of hydrogen-rich material on the WD surface may trigger re-ignition of thermonuclear reactions that, under degenerate conditions, lead to an explosive ejection of the accreted layer mixed with WD material. These explosions, known as classical novae, provide opportunities to study key astrophysical processes such as binary evolution, accretion, ionisation of circumstellar material, mass ejection, jet formation, and thermonuclear burning. Radio emission in these systems arises from both thermal and non-thermal processes, which manifest differently in classical and symbiotic novae. $\gamma$-ray emission has also been detected in several cases, and recent progress, driven by coordinated radio and multiwavelength observations, has greatly advanced our understanding of both types of novae. Multi-frequency, multi-epoch, and multi-scale interferometric observations are powerful probes of the evolving physical conditions following thermonuclear explosions, revealing information from both ionised and relativistic particle populations. The SKAO, particularly its SKA-Mid component, will enable regular monitoring of Galactic novae, multiple times per year for classical novae and every few years for symbiotic systems. It will explore a wide range of conditions, including companion types, WD masses, accretion regimes, and surrounding environments. The VLBI capabilities of the SKAO will target compact shocked regions, while its exceptional sensitivity will also allow characterisation of emission during quiescent phases of the binaries.
Read the full abstract

All authors Rocco Lico, Marcello Giroletti, Arnau Aguasca-Cabot, Joris Kersten, Benito Marcote, Ulisse Munari, Miriam M. Nyamai, Timothy J. O'Brien, Zsolt Paragi, Iris de Ruiter, Kirill Sokolovsky, David R. A. Williams

Solar and Stellar Astrophysics

Evolved massive stars and their impact on their environment

C.S. Buemi, G. Umana, C. Trigilio et al. (+15 more)

The comprehension of the final stages of massive star evolution and their path toward the eventual supernova explosion necessarily involves the study of stellar winds and the circumstellar environment (CSE) surrounding them in the transitional phases, during which stellar winds and eruptive mass loss profoundly shape the surrounding environment. The study of the pre-supernova progenitors, from Red Supergiants, passing through the Luminous Blue Variable stage to Wolf-Rayet stars, is of key importance because, focusing on their nebulae, they directly prove the mass-loss activity of the star that, through wind and eruptive events, shapes the environment in which the supernova will explode. Such environment, interacting with the ejecta, will heavily affect supernovae spectrophotometric signatures. The Square Kilometre Array, with its extraordinary capabilities to combine high spatial resolution, sensitivity and wide frequency coverage will adress the most critical observational issues that currently prevent detailed characterization of CSE and, thus limit our ability to constrain its connections to supernova and remnants proprierties.
Read the full abstract

All authors C.S. Buemi, G. Umana, C. Trigilio, C. Bordiu, F. Bufano, J. van den Eijnden, S. Orlando, P. Leto, F. Bocchino, M. Miceli, M. Pérez-Torres, A. Alberdi, F. Cavallaro, L. Cerrigone, A. Ingallinera, S. Loru, S. Riggi, A.C. Ruggeri

Soft Condensed Matter

Mechanical response of quasi-two-dimensional colloidal clusters under uniaxial tension

Yanhui Yang, Jiawei Kang, Yao Li et al. (+1 more)

Despite extensive studies of equilibrium conformations of colloidal clusters, little is known about their mechanical response. Here, we investigate the tensile behavior of a quasi-two-dimensional colloidal cluster subjected to uniaxial tension up to fracture. The sample is a ribbon-shaped assembly of 16 colloidal beads bound by short-range depletion attraction. Using multiple optical tweezers, we clamp the cluster at both ends and perform a tensile test along its long axis. Combining video microscopy with particle tracking, we measure the tensile stress, strain, and particle configurations during deformation. We observe diverse mechanical response behaviors, including elastic, plastic, and soft-mode deformation, with fracture occurring at a strain near 10%. To explain these behaviors, we construct a spring-mass frame model with breakable elastic bonds. We perform canonical Monte Carlo simulations on the full model with 32 degrees of freedom and compute the statistical distributions of mechanical observables using a simplified model with only 7 degrees of freedom. Both the simulations and the theoretical calculations accurately reproduce the experimental stress–strain curves. Moreover, the configuration distributions predicted by the simplified model agree well with both experiment and simulation in the elastic and soft-mode regimes, with only minor discrepancies in the plastic regime. This work demonstrates that the simplified spring-mass model captures the essential physics governing the rich tensile response behavior of the colloidal cluster.
Read the full abstract

All authors Yanhui Yang, Jiawei Kang, Yao Li, Xiaoguang Ma

Cosmology and Nongalactic Astrophysics

Constraining supermassive primordial black hole clustering with the angular auto-correlation of $z\simeq 6$ quasars

Zhan-He Wang, Hai-Long Huang and Yun-Song Piao

High-redshift quasars provide a direct probe of the origin and environment of the earliest supermassive black holes. We use their angular auto-correlation function at $z\simeq 6$ to test scenarios in which supermassive primordial black holes (SMPBHs) are associated with the observed quasar population. The evolved PBH correlation functions, for both Poisson fluctuations and initial PBH clustering, are projected over the quasar redshift window and compared with the measured angular correlation function using Markov chain Monte Carlo inference. It is observed that for the Poisson model, the posterior favors a small abundance, $f_{\rm PBH}\sim 10^{-3}$, and a supermassive effective mass scale, $m_{\rm PBH}\sim 10^{12}M_\odot$, interpreted here as a scale controlling quasar host-halo formation and clustering, and for the initially clustered model, the data prefer an effective clustering amplitude $\xi_{\rm eff}\simeq 2.1$ and a top-hat boundary scale $r_{\rm cl}\simeq 76\,{\rm Mpc}$, corresponding to weak relative contraction of PBH pairs in comoving coordinates.
Read the full abstract

Quantum Physics

Two-dimensional Hyperbolic RNN Neural Quantum State

H. L. Dao

In the first part of this work, we construct the first type of two-dimensional (2D) hyperbolic neural quantum state (NQS) in the form of the Lorentz 2DRNN (Recurrent Neural Network) and benchmark its performance against the Euclidean 2DRNN in the paradigmatic $N \times N$ 2D Transverse Field Ising Model (2DTFIM) setting with different lattice sizes up to N = 12 at different transverse magnetic field strengths. We find that hyperbolic Lorentz 2DRNN NQS robustly outperforms Euclidean 2DRNN NQS in our experiments when the system is at the phase transition point, where the physics can be described by a conformal field theory (CFT) - known via the AdS/CFT holographic duality to possess an underlying hyperbolic geometry. In the second part of this work, we benchmark the performances of recently introduced one-dimensional (1D) hyperbolic NQS ansatzes (including Poincare RNN/GRU and Lorentz RNN/GRU) against their Euclidean versions in $N \times N$ 2DTFIM, converted to a one-dimensional sequence. The findings extend our previous results showing that 1D hyperbolic NQS robustly outperforms 1D Euclidean NQS, thanks to the combined effects of the induced 1st and Nth neighbor interaction hierarchy and the CFT physics at criticality. While studies on larger system sizes remain future work, this study serves as a proof-of-concept for the utility, effectiveness, and superior performance of 1D and 2D hyperbolic NQS ansatzes compared to conventional Euclidean NQS models in many-body quantum systems - particularly those exhibiting structural hierarchy, criticality, or a combination of both.
Read the full abstract