Current date: 2025-10-16

Setting default datestamp limit: 0

Datestamp limit: 2025-10-16 (0 days ago)

Created/updated limit: 2025-10-09 (7 days ago)

Suggested sets: physics, physics:astro-ph, physics:gr-qc, physics:physics

Setting default set: physics

OAI-PMH request: http://export.arxiv.org/oai2?verb=ListRecords&from=2025-10-16&until=2025-10-16&set=physics&metadataPrefix=arXiv

Scoring abstracts

Number of records retrieved: 625

Keyword score statistics

score 11 -- 1 abstracts

score 7 -- 1 abstracts

score 6 -- 1 abstracts

score 4 -- 4 abstracts

score 3 -- 10 abstracts

score 2 -- 22 abstracts

in total -- 39 abstracts

Articles that appeared on 2025-10-16

[abstract 1 / 39] Wow! (score: 11)
arXiv:2510.13776 [pdf, ps, other]

Title: Polarization dynamics of X-ray SYNCHROTRON emission from a multi-zone BLAZAR JET

Authors: Benjamin de Jonge, Haocheng Zhang, Manel Errando, Andrea Gokus, Pazit Rabinowitz,

Comments: 15 pages, 11 figures

Subjects: astro-ph.HE

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

The POLARIZATION of X-ray SYNCHROTRON emission in BLAZARs offers a direct probe into the MAGNETic field geometry and particle acceleration processes operating in RELATIVISTIC JETs. We use particle-in-cell simulations of MAGNETic RECONNECTion and MAGNETized turbulence, coupled to POLARIZATION-sensitive radiative transfer code, to interpret IXPE observations of Mrk 421 during a high flux state recorded in December of 2023. To evaluate the fitness of the theoretical scenarios, we rely on a quantitative comparison the statistical properties of simulated and observed X-ray flux and POLARIZATION light curves using five evaluation metrics, rather than attempting to fit individual data points. We propose a multi-zone model where JET emission is represented as the sum of the radiative output of many independent cells, each described by a simulation run viewed at different orientations. Comparison of ensembles of simulated Stokes-parameter light curves with IXPE data shows that MAGNETic RECONNECTion dominated models provide the best match to the observed X-ray flux and POLARIZATION dynamics. The optimal configuration corresponds to N = 15 emitting cells, which reproduces the observed amplitudes and timescales of the X-ray flux and POLARIZATION variations. Magnetized turbulence models underpredict both the flux and POLARIZATION variability. Our results indicate that a multi-zone, RECONNECTion-powered emission scenario can describe the X-ray POLARIZATION behavior of Mrk 421 and establish a quantitative framework for testing theoretical models against IXPE observations of other high-SYNCHROTRON-peaked BLAZARs.

[abstract 2 / 39] Wow! (score: 7)
arXiv:2510.13337 [pdf, ps, other]

Title: Relativistic reflection within an extended hot plasma geometry

Authors: Alexey D. Nekrasov, Thomas Dauser, Javier A. Garcia, Dominic J. Walton, Christian M. Fromm, Andrew J. Young, Fergus J. E. Baker, Amy M. Joyce, Ole Koenig, Stefan Licklederer, Julia Haefner, Joern Wilms,

Comments: 14 pages, 10 figures, accepted for publication by A&A, the new RELXILL model can be downloaded at https://www.sternwarte.uni-erlangen.de/research/relxill/

Subjects: astro-ph.HE

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Reflection of X-rays at the inner accretion disk around BLACK HOLEs imprints RELATIVISTICally broadened features in the observed spectrum. Besides the BLACK HOLE properties and the ionization and density of the accretion disk the features also depend on the location and geometry of the primary source of X-rays, often called the corona. We present a fast general RELATIVISTIC model for spectral fitting of a radially extended, ring-like corona above the accretion disk. A commonly used model to explain observed X-ray reflection spectra is the lamp post, which assumes a point-like source on the rotational axis of the BLACK HOLE. While often being able to explain the observations, this geometric model does not allow for a constraint on the radial size of the corona. We therefore extend the publicly available RELATIVISTIC reflection model RELXILL by implementing a radially extended, ring-like primary source. With the new RELXILL model allowing us to vary the position of the primary source in two dimensions, we present simulated line profiles and spectra and discuss implications of data fitting compared to the lamp post model. We then apply this extended RELXILL model to XMM-Newton and NUSTAR data of the radio-quiet Seyfert-2 AGN ESO 033-G002. The new model describes the data well, and we are able to constrain the distance of the source to the BLACK HOLE to be less than three gravitational radii, while the angular position of the source is poorly constrained. We show that a compact, radially extended corona close to the ISCO can explain the observed RELATIVISTIC reflection equally well as the point-like lamp post corona. The model is made freely available to the community.

[abstract 3 / 39] Yes (score: 6)
arXiv:2510.13249 [pdf, ps, other]

Title: Monte Carlo simulation of the Compton scattering and disk reflection of a cylinder with hot electrons moving away from a BLACK HOLE

Authors: Wei Meng, Yuan You, Shuang-Nan Zhang, Jia-Ying Cao,

Comments: 26 pages, 27 figures, 2 tables, submitted

Subjects: astro-ph.HE

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

For accreting BLACK HOLEs (BHs), the lamp-post scenario is a simple and popular model: a hot and point-like corona is located above the BLACK HOLE, irradiating the accretion disk with hard X-ray radiation, which is believed to be generated by inverse Compton scattering in the corona. Although the lamp-post model successfully explains the disk reflection component, it fails to address the origin of seed photons and the geometry of the hot corona, because this model simplistically treats the corona as a point-like source generating a cutoff powerlaw spectrum. In this paper, we make simulations on a possible physical realization of the lamp-post scenario: the shape of the scattering zone is set to be a cylinder, corresponding to the JET base near a BH. The source of seed photons in this system is assumed to be the multicolor blackbody radiation of the accretion disk. In our simulations, the Compton scattering process is simulated with a custom Monte Carlo program based on the Geant4 package and the disk reflection process is simulated with the xilconv model in XSPEC. Our simulation results have confirmed that the RELATIVISTIC motion of the JET can weaken or even completely suppress the reflection of the accretion disk, and simultaneously, the Comptonization of disk photons in the JET can still make a major contribution to the observed X-ray spectrum in high energy range. We discuss the implications of our simulation results, in light of the recent observations of a very weak reflection component in the presence of a strong hard X-ray radiation from the outburst of SWIFT J1727.8-1613.

[abstract 4 / 39] Yes (score: 4)
arXiv:2510.11772 [pdf, ps, other]

Title: MESA-QUEST: Tracing the formation of direct collapse BLACK HOLE seeds via quasi-stars

Authors: Andrew D. Santarelli, Claire B. Campbell, Ebraheem Farag, Earl P. Bellinger, Priyamvada Natarajan, Matthew E. Caplan,

Comments: 14 pages, 3 figures, submitted to the Astrophysical Journal

Subjects: astro-ph.HE astro-ph.CO astro-ph.GA

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

The origin of the first supermassive BLACK HOLEs (SMBHs) observed at redshifts $z\geq 9$ remains one of the most challenging open questions in astrophysics. Their rapid emergence suggests that massive ``heavy seeds'' must have formed early, possibly through the direct collapse of pristine gas clouds in the first galaxies. We present MESA-QUEST, a new framework built upon the Modules for Experiments in Stellar Astrophysics (MESA) code, designed to model the structure and evolution of quasi-stars -- massive, radiation-supported envelopes hosting accreting BLACK HOLEs at their cores -- believed to be the progenitors of direct-collapse BLACK HOLE (DCBH) seeds. Our implementation introduces flexible boundary conditions representing both Bondi accretion and saturated-convection regimes, and explores the impact of several stellar wind and mass-loss prescriptions, including Reimers, Dutch, and super-Eddington radiation-driven winds. We find that quasi-stars can grow central BLACK HOLEs to $\geq 10^3\,M_{\odot}$ under favorable conditions, with saturated-convection models yielding BH-to-total mass ratios up to 0.55$M_*$ -- five times higher than Bondi-limited cases. However, strong radiation-driven winds can dramatically curtail growth, potentially quenching heavy-seed formation unless balanced by sustained envelope accretion. Our results delineate the physical limits under which quasi-stars can remain stable and produce heavy seeds capable of evolving into the earliest SMBHs detected by JWST and Chandra. Future extensions will incorporate rotation, MAGNETic fields, and GR-radiation hydrodynamics to refine accretion physics and constrain the viability of the quasi-star pathway for early SMBH formation.

[abstract 5 / 39] Yes (score: 4)
arXiv:2510.12869 [pdf, ps, other]

Title: Unified kinetic theory of induced scattering: Compton, Brillouin, and Raman processes in MAGNETized electron and positron pair plasma

Authors: Rei Nishiura, Shoma F. Kamijima, Kunihito Ioka,

Comments: 34 pages, 6 figures. Comments welcome

Subjects: astro-ph.HE physics.plasm-ph

Created: 2025-10-14; Updated: 2025-10-16; Datestamp: 2025-10-16

We present a unified theoretical framework for induced (stimulated) scattering-parametric instabilities of electroMAGNETic waves, including induced Compton, stimulated Brillouin, and stimulated Raman scattering (SRS) in strongly MAGNETized electron-positron pair plasma. By solving the dispersion relations derived from kinetic theory, taking into account the ponderomotive force due to the beat of incident and scattered waves, we obtain analytical expressions for the linear growth rates of the ordinary, neutral, and charged modes of density fluctuations. Our results clarify which type of scattering dominates under different thermal coupling, resonance, and density conditions. In strong MAGNETic fields, scattering of perpendicularly polarized waves is generally suppressed, but by different powers of the cyclotron frequency. Moreover, SRS, which is forbidden in unMAGNETized electron and positron pair plasma, becomes possible in the charged mode. This framework enables a comprehensive evaluation of induced scattering in extreme astrophysical and laboratory plasma, such as fast radio burst (FRB) emission and propagation in MAGNETar MAGNETospheres.

[abstract 6 / 39] Yes (score: 4)
arXiv:2510.12895 [pdf, ps, other]

Title: Mean Motion Resonances in AGN Disks

Authors: Marguerite Epstein-Martin, Nicholas Stone, Juliette Becker,

Comments: 23 pages, 7 figures

Subjects: astro-ph.HE

Created: 2025-10-14; Updated: 2025-10-16; Datestamp: 2025-10-16

Mean motion resonances (MMRs) are a generic outcome of convergent migration for bodies embedded in accretion disks around a central mass. Long studied in planetary systems, the same phenomenon should occur for stellar-mass BLACK HOLEs (BHs) in AGN disks. In this work, we derive simple analytic criteria describing when BH pairs are driven out of resonance, and use them to chart MMR stability across AGN parameter space, accounting for disruption from general-RELATIVISTIC apsidal precession, hydrodynamic turbulence, and stellar stirring. Across plausible AGN disk models, we find three MBH mass regimes: (i) for $M/ M_\odot\gtrsim 10^{7.5}$, first order resonances are generically unstable; (ii) for $M/ M_\odot\lesssim 10^{6.5}$, stable MMRs are always present; (iii) for $10^{6.5}\lesssim M / M_\odot \lesssim 10^{7.5}$, stability depends on disk mass flux, the summed mass of the orbiters, and the nuclear-cusp slope. When present, stable MMRs commonly occur between an inner anti-trap and an outer trap set by thermal torque, a region where embedded objects migrate outward in the disk. These results imply that high-mass AGN allow convergent migration to proceed to LVK-band mergers largely without resonant chains, whereas low/intermediate-mass AGN can host MMRs, with the potential to reshape merger pathways.

[abstract 7 / 39] Yes (score: 4)
arXiv:2510.12965 [pdf, ps, other]

Title: Cosmic Ray Transport and Gamma-Ray Signatures in the Interstellar Medium

Authors: Lucas Barreto-Mota, Elisabete M. de Gouveia Dal Pino, Siyao Xu, Alexandre Lazarian, Rafael Alves-Batista, Gaetano Di Marco, Stela Adduci Faria,

Comments: Proceeding ICRC 2025

Subjects: astro-ph.HE

Created: 2025-10-14; Updated: 2025-10-16; Datestamp: 2025-10-16

The interaction of COSMIC RAYs (CRs) with MAGNETic fields and the interstelar medium (ISM) leads to the production of nonthermal radiation. Although this has been a topic of study for many years, it still poses many challenges to the understanding of these processes. In this work we present a short review of recent advances in the understanding of CR propagation in MAGNETohydrodynamical (MHD) turbulence, in particular the process of mirror diffusion, and how it can help explain recent observational constraints for CR diffusion away from sources. We also present preliminary results from Monte Carlo simulations of CR cascading and propagation within a young massive stellar cluster (YMSC), aimed at probing the origin of very-high-energy (VHE) emission from these sources.

[abstract 8 / 39] (score: 3)
arXiv:2501.19404 [pdf, ps, other]

Title: Spin oscillations of neutrinos scattered by the supermassive BLACK HOLE in the galactic center

Authors: Mridupawan Deka, Maxim Dvornikov,

Comments: 40 pages, 23 figures

Subjects: hep-ph astro-ph.HE gr-qc

Created: 2025-10-14; Updated: 2025-10-16; Datestamp: 2025-10-16

In this work, we study the propagation and spin oscillations of neutrinos in their scattering by a supermassive BLACK HOLE (SMBH) surrounded by a realistic accretion disk. We review various descriptions of the fermion spin evolution in a curved spacetime under the influence of external fields. The overview of the test particle motion in the gravitational field of a rotating SMBH is also present. The external fields which a neutrino spin interacts with are the electroweak forces in plasma and the toroidal MAGNETic field in the accretion disk surrounding SMBH. Spin precession of neutrinos, which are supposed to be Dirac particles, is caused by the interaction of the neutrino MAGNETic moment with the MAGNETic field in the disk. We use a semi-analytical model of a thick accretion disk and review its characteristics. The cases of co-rotating and counter-rotating disks with respect to BH are discussed. We consider the incoming flux of neutrinos having an arbitrary angle with respect to the BH spin since the recent results of the Event Horizon Telescope indicate that the BH spin in the galactic center is not always perpendicular to the galactic plane. For our study, we consider a large number of incoming test neutrinos. We briefly discuss our results and their applications in the observations of astrophysical neutrinos.

[abstract 9 / 39] (score: 3)
arXiv:2507.07209 [pdf, ps, other]

Title: 20 GeV halo-like excess of the Galactic diffuse emission and implications for DARK MATTER annihilation

Authors: Tomonori Totani,

Comments: 32 pages, 16 figures. Accepted for publication in JCAP

Subjects: astro-ph.HE astro-ph.CO hep-ph

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Fifteen years of the FERMI Large Area Telescope (LAT) data in the halo region of the Milky Way (MW) are analyzed to search for gamma rays from DARK MATTER annihilation. Gamma-ray maps within the region of interest ($|l| \le 60^\circ$, $10^\circ \le |b| \le 60^\circ$) are modeled using point sources, the GALPROP models of cosmic-ray interactions, isotropic background, and templates of Loop I and the FERMI bubbles, and then the presence of a halo-like component is further examined. A statistically significant halo-like excess is found with a spectral peak around 20 GeV, while its flux is consistent with zero below 2 GeV and above 200 GeV. Examination of the fit residual maps indicates that a spherically symmetric halo component fits the map data well. The radial profile agrees with annihilation by the smooth NFW density profile, and may be slightly shallower than this, especially in the central region. Various systematic uncertainties are investigated, but the 20 GeV peak remains significant. In particular, the halo excess with a similar spectrum is detected even relative to the LAT standard background model, which contains non-template patches adjusted to match the observed map. The halo excess spectrum can be fitted by annihilation with a particle mass $m_χ\sim$ 0.5-0.8 TeV and cross section $\langle σ\upsilon \rangle \sim$ (5-8)$\times 10^{-25} \ \rm cm^3 \, s^{-1}$ for the $b\bar{b}$ channel. This cross section is larger than the upper limits from dwarf galaxies and the canonical thermal relic value, but considering various uncertainties, especially the density profile of the MW halo, the DARK MATTER interpretation of the 20 GeV ``FERMI halo'' remains feasible. The prospects for verification through future observations are briefly discussed.

[abstract 10 / 39] (score: 3)
arXiv:2508.04375 [pdf, ps, other]

Title: Low-frequency spectra of neutron star + OB supergiant binaries: Does wind density drive persistent and flaring modes of accretion?

Authors: J. van den Eijnden, L. Sidoli, M. Díaz Trigo, I. El Mellah, V. Sguera, N. Degenaar, F. Fürst, V. Grinberg, P. Kretschmar, S. Martínez-Núñez, J. C. A. Miller-Jones, K. Postnov, T. D. Russell,

Comments: Accepted for publication in MNRAS. 20 pages, 10 figures, 4 tables. Updated Zenodo DOI for Data Reproduction Package

Subjects: astro-ph.HE astro-ph.SR

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Neutron star high-mass X-ray binaries are well-studied in wavebands between the infrared and hard X-rays. Their low-frequency millimeter and radio properties, on the other hand, remain poorly understood. We present observations of the millimeter and radio emission of binaries where a neutron star accretes from an OB supergiant. We report ALMA and NOEMA millimeter observations of twelve systems, supplemented by VLA radio observations of six of those targets. Our targets include six Supergiant X-ray Binaries (SgXBs), four Supergiant Fast X-ray Transients (SFXTs), and two intermediate systems. Nine out of twelve targets, including all SFXTs, are detected in at least one millimeter band, while in the radio, only two targets are detected. All detected targets display inverted radio/millimeter spectra, with spectral indices in the range $α=0.6-0.8$ for those systems where accurate SED fits could be performed. We conclude, firstly, that the low-frequency SEDs of neutron star SFXTs and SgXBs are dominated by free-free emission from the OB supergiant's stellar wind, and that JET emission is unlikely to be observed unless the systems can be detected at sub-GHz frequencies. Secondly, we find that SFXTs are fainter at 100 GHz than prototypical SgXBs, probably due to systematically less dense winds in the former, as supported further by the differences in their fluorescence Fe K$α$ lines. We furthermore compare the stellar wind constraints obtained from our millimeter observations with those from IR/optical/UV studies and bow shock detections, and present evidence for long-term stellar wind variability visible in the thermal emission.

[abstract 11 / 39] (score: 3)
arXiv:2509.17535 [pdf, ps, other]

Title: Observational features of the Bardeen-BOSON star with thin disk accretion

Authors: Chen-Yu Yang, Huan Ye, Xiao-Xiong Zeng,

Comments: some figures and statement are added

Subjects: gr-qc

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

In this work, we construct spherically symmetric solutions of Bardeen--BOSON stars within the framework of the Einstein--Klein--Gordon theory coupled to nonlinear electrodynamics by employing numerical methods. Considering a thin accretion disk in the equatorial plane as the light source, we systematically investigate the optical appearance of BOSON stars using the ray-tracing method and the stereographic projection technique. Particular attention is paid to the influence of the initial scalar field $ϕ_0$, the MAGNETic charge $\mathcal{G}$, and the observation angle $θ_o$, on the image structure. As compact horizonless objects, BOSON stars produce optical images dominated by direct emission, while their morphology undergoes significant distortions as $θ_o$ increases. Higher values of $ϕ_0$ and $θ_o$ can give rise to lensing images. For all the parameters, the image center exhibits a brightness depression similar to the inner shadow of BLACK HOLEs, which poses challenges for distinguishing between BOSON stars and BLACK HOLEs. To address this, we propose two possible approaches: (i) combining the analysis of lensing bands with the effective potential to determine the existence of photon rings; and (ii) examining the POLARIZATION effects under SYNCHROTRON emission mechanisms. These results provide theoretical support for future high-resolution imaging efforts aimed at discriminating BOSON stars from BLACK HOLEs.

[abstract 12 / 39] (score: 3)
arXiv:2510.12860 [pdf, ps, other]

Title: Spatial Variations of Polarized Synchrotron Emission in the QUIJOTE MFI Data

Authors: J. M. Casas, L. Bonavera, J. González-Nuevo, J. A. Rubiño-Martín, R. T. Génova-Santos, R. B. Barreiro, M. M. Cueli, D. Crespo, R. Fernández-Fernández, J. A. Cano,

Comments: Submitted to Astronomy & Astrophysics

Subjects: astro-ph.GA astro-ph.CO

Created: 2025-10-14; Updated: 2025-10-16; Datestamp: 2025-10-16

Polarized SYNCHROTRON emission from ultra-RELATIVISTIC electrons spiraling the Galactic MAGNETic field has become one of the most relevant emissions in the Interstellar medium these last years due to the improvement in the quality of low-frequency observations. One of the recent experiments designed to explore this emission is the QUIJOTE experiment. We aim to study the spatial variations of the SYNCHROTRON emission in the QUIJOTE MFI data, by dividing the sky into physically separated regions. For such task, we firstly use a novel component separation method based on artificial neural networks to clean the SYNCHROTRON maps. After training the network with simulations, we fit both $EE$ and $BB$ spectra by assuming a power-law model. Then, we give estimations for the index $α_{S}$, the amplitude, and the ratio between $B$ and $E$ amplitudes. When analyzing the real data, we found a clear spatial variation of the SYNCHROTRON properties along the sky at 11 GHz, obtaining a steeper index in the Galactic plane of $α_{S}^{EE} = -3.1 \pm 0.3$ and $α_{S}^{BB} = -3.1 \pm 0.4$ and a flatter one at high Galactic latitudes of $α_{S}^{EE} = -3.05 \pm 0.2$ and $α_{S}^{B} = -2.98 \pm 0.27$. We found average values at all sky of $α_{S}^{EE} = -3.04 \pm 0.21$ and $α_{S}^{BB} = -3.00 \pm 0.34$. Furthermore, after obtaining an average value of $A_{S}^{EE} = 3.31 \pm 0.08$ $μK^{2}$ and $A_{S}^{BB} = 0.93 \pm 0.02$ $μK^{2}$, we estimate a ratio between $B$ and $E$ amplitudes of $A_{S}^{BB}/A_{S}^{EE} = 0.28 \pm 0.08$. Based on the results we conclude that, although neural networks seem to be valuable methods to apply on real ISM observations, combined analyses with Planck, WMAP and/or CBASS data are mandatory to reduce the contamination from QUIJOTE maps and then improve the accuracy of the estimations.

[abstract 13 / 39] (score: 3)
arXiv:2510.13403 [pdf, ps, other]

Title: Evidence for Neutrino Emission from X-ray Bright Active Galactic Nuclei with IceCube

Authors: R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J. M. Alameddine, S. Ali, N. M. Amin, K. Andeen, C. Argüelles, Y. Ashida, S. Athanasiadou, S. N. Axani, R. Babu, X. Bai, J. Baines-Holmes, A. Balagopal V., S. W. Barwick, S. Bash, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, P. Behrens, J. Beise, C. Bellenghi, B. Benkel, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, E. Blaufuss, L. Bloom, S. Blot, I. Bodo, F. Bontempo, J. Y. Book Motzkin, C. Boscolo Meneguolo, S. Böser, O. Botner, J. Böttcher, J. Braun, B. Brinson, Z. Brisson-Tsavoussis, R. T. Burley, D. Butterfield, M. A. Campana, K. Carloni, J. Carpio, S. Chattopadhyay, N. Chau, Z. Chen, D. Chirkin, S. Choi, B. A. Clark, A. Coleman, P. Coleman, G. H. Collin, D. A. Coloma Borja, A. Connolly, J. M. Conrad, D. F. Cowen, C. De Clercq, J. J. DeLaunay, D. Delgado, T. Delmeulle, S. Deng, P. Desiati, K. D. de Vries, G. de Wasseige, T. DeYoung, J. C. Díaz-Vélez, S. DiKerby, T. Ding, M. Dittmer, A. Domi, L. Draper, L. Dueser, D. Durnford, K. Dutta, M. A. DuVernois, T. Ehrhardt, L. Eidenschink, A. Eimer, P. Eller, E. Ellinger, D. Elsässer, R. Engel, H. Erpenbeck, W. Esmail, S. Eulig, J. Evans, P. A. Evenson, K. L. Fan, K. Fang, K. Farrag, A. R. Fazely, A. Fedynitch, N. Feigl, C. Finley, L. Fischer, D. Fox, A. Franckowiak, S. Fukami, P. Fürst, J. Gallagher, E. Ganster, A. Garcia, M. Garcia, G. Garg, E. Genton, L. Gerhardt, A. Ghadimi, T. Glüsenkamp, J. G. Gonzalez, S. Goswami, A. Granados, D. Grant, S. J. Gray, S. Griffin, S. Griswold, K. M. Groth, D. Guevel, C. Günther, P. Gutjahr, C. Ha, C. Haack, A. Hallgren, L. Halve, F. Halzen, L. Hamacher, M. Ha Minh, M. Handt, K. Hanson, J. Hardin, A. A. Harnisch, P. Hatch, A. Haungs, J. Häußler, K. Helbing, J. Hellrung, B. Henke, L. Hennig, F. Henningsen, L. Heuermann, R. Hewett, N. Heyer, S. Hickford, A. Hidvegi, C. Hill, G. C. Hill, R. Hmaid, K. D. Hoffman, D. Hooper, S. Hori, K. Hoshina, M. Hostert, W. Hou, M. Hrywniak, T. Huber, K. Hultqvist, K. Hymon, A. Ishihara, W. Iwakiri, M. Jacquart, S. Jain, O. Janik, M. Jansson, M. Jeong, M. Jin, N. Kamp, D. Kang, W. Kang, X. Kang, A. Kappes, L. Kardum, T. Karg, M. Karl, A. Karle, A. Katil, M. Kauer, J. L. Kelley, M. Khanal, A. Khatee Zathul, A. Kheirandish, H. Kimku, J. Kiryluk, C. Klein, S. R. Klein, Y. Kobayashi, A. Kochocki, R. Koirala, H. Kolanoski, T. Kontrimas, L. Köpke, C. Kopper, D. J. Koskinen, P. Koundal, M. Kowalski, T. Kozynets, A. Kravka, N. Krieger, J. Krishnamoorthi, T. Krishnan, K. Kruiswijk, E. Krupczak, A. Kumar, E. Kun, N. Kurahashi, N. Lad, C. Lagunas Gualda, L. Lallement Arnaud, M. Lamoureux, M. J. Larson, F. Lauber, J. P. Lazar, K. Leonard DeHolton, A. Leszczyńska, J. Liao, C. Lin, Q. R. Liu, Y. T. Liu, M. Liubarska, C. Love, L. Lu, F. Lucarelli, W. Luszczak, Y. Lyu, M. Macdonald, J. Madsen, E. Magnus, Y. Makino, E. Manao, S. Mancina, A. Mand, I. C. Mariş, S. Marka, Z. Marka, L. Marten, I. Martinez-Soler, R. Maruyama, J. Mauro, F. Mayhew, F. McNally, J. V. Mead, K. Meagher, S. Mechbal, A. Medina, M. Meier, Y. Merckx, L. Merten, J. Mitchell, L. Molchany, S. Mondal, T. Montaruli, R. W. Moore, Y. Morii, A. Mosbrugger, M. Moulai, D. Mousadi, E. Moyaux, T. Mukherjee, R. Naab, M. Nakos, U. Naumann, J. Necker, L. Neste, M. Neumann, H. Niederhausen, M. U. Nisa, K. Noda, A. Noell, A. Novikov, A. Obertacke, V. O'Dell, A. Olivas, R. Orsoe, J. Osborn, E. O'Sullivan, V. Palusova, H. Pandya, A. Parenti, N. Park, V. Parrish, E. N. Paudel, L. Paul, C. Pérez de los Heros, T. Pernice, T. C. Petersen, J. Peterson, M. Plum, A. Pontén, V. Poojyam, Y. Popovych, M. Prado Rodriguez, B. Pries, R. Procter-Murphy, G. T. Przybylski, L. Pyras, C. Raab, J. Rack-Helleis, N. Rad, M. Ravn, K. Rawlins, Z. Rechav, A. Rehman, I. Reistroffer, E. Resconi, S. Reusch, C. D. Rho, W. Rhode, L. Ricca, B. Riedel, A. Rifaie, E. J. Roberts, M. Rongen, A. Rosted, C. Rott, T. Ruhe, L. Ruohan, D. Ryckbosch, J. Saffer, D. Salazar-Gallegos, P. Sampathkumar, A. Sandrock, G. Sanger-Johnson, M. Santander, S. Sarkar, J. Savelberg, M. Scarnera, P. Schaile, M. Schaufel, H. Schieler, S. Schindler, L. Schlickmann, B. Schlüter, F. Schlüter, N. Schmeisser, T. Schmidt, F. G. Schröder, L. Schumacher, S. Schwirn, S. Sclafani, D. Seckel, L. Seen, M. Seikh, S. Seunarine, P. A. Sevle Myhr, R. Shah, S. Shefali, N. Shimizu, B. Skrzypek, R. Snihur, J. Soedingrekso, A. Søgaard, D. Soldin, P. Soldin, G. Sommani, C. Spannfellner, G. M. Spiczak, C. Spiering, J. Stachurska, M. Stamatikos, T. Stanev, T. Stezelberger, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, S. Ter-Antonyan, A. Terliuk, A. Thakuri, M. Thiesmeyer, W. G. Thompson, J. Thwaites, S. Tilav, K. Tollefson, S. Toscano, D. Tosi, A. Trettin, A. K. Upadhyay, K. Upshaw, A. Vaidyanathan, N. Valtonen-Mattila, J. Valverde, J. Vandenbroucke, T. Van Eeden, N. van Eijndhoven, L. Van Rootselaar, J. van Santen, J. Vara, F. Varsi, M. Venugopal, M. Vereecken, S. Vergara Carrasco, S. Verpoest, D. Veske, A. Vijai, J. Villarreal, C. Walck, A. Wang, E. H. S. Warrick, C. Weaver, P. Weigel, A. Weindl, J. Weldert, A. Y. Wen, C. Wendt, J. Werthebach, M. Weyrauch, N. Whitehorn, C. H. Wiebusch, D. R. Williams, L. Witthaus, M. Wolf, G. Wrede, X. W. Xu, J. P. Yanez, Y. Yao, E. Yildizci, S. Yoshida, R. Young, F. Yu, S. Yu, T. Yuan, A. Zander Jurowitzki, A. Zegarelli, S. Zhang, Z. Zhang, P. Zhelnin, P. Zilberman,

Comments: 24 pages, 13 figures, 3 tables

Subjects: astro-ph.HE

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Recently, IceCube reported neutrino emission from the Seyfert galaxy NGC 1068. Using 13.1 years of IceCube data, we present a follow-up search for neutrino sources in the northern sky. NGC 1068 remains the most significant neutrino source among 110 preselected gamma-ray emitters while also being spatially compatible with the most significant location in the northern sky. Its energy spectrum is characterized by an unbroken power-law with spectral index $γ= 3.4 \pm 0.2$. Consistent with previous results, the observed neutrino flux exceeds its gamma-ray counterpart by at least two orders of magnitude. Motivated by this disparity and the high X-ray luminosity of the source, we selected 47 X-ray bright Seyfert galaxies from the SWIFT/BAT spectroscopic survey that were not included in the list of gamma-ray emitters. When testing this collection for neutrino emission, we observe a 3.3$σ$ excess from an ensemble of 11 sources, with NGC 1068 excluded from the sample. Our results strengthen the evidence that X-ray bright cores of ACTIVE GALACTIC NUCLEi are neutrino emitters.

[abstract 14 / 39] (score: 3)
arXiv:2510.13521 [pdf, ps, other]

Title: Narrow Operator Models of Stellarator Equilibria in Fourier Zernike Basis

Authors: Timo Thun, Rory Conlin, Dario Panici, Daniel Böckenhoff,

Comments: 15 pages, 6 figures, 1 table

Subjects: physics.plasm-ph cs.AI cs.LG

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Numerical computation of the ideal Magnetohydrodynamic (MHD) equilibrium MAGNETic field is at the base of stellarator optimisation and provides the starting point for solving more sophisticated Partial Differential Equations (PDEs) like transport or turbulence models. Conventional approaches solve for a single stationary point of the ideal MHD equations, which is fully defined by three invariants and the numerical scheme employed by the solver. We present the first numerical approach that can solve for a continuous distribution of equilibria with fixed boundary and rotational transform, varying only the pressure invariant. This approach minimises the force residual by optimising parameters of multilayer perceptrons (MLP) that map from a scalar pressure multiplier to the Fourier Zernike basis as implemented in the modern stellarator equilibrium solver DESC.

[abstract 15 / 39] (score: 3)
arXiv:2510.13569 [pdf, ps, other]

Title: Orbital dynamics and precession in MAGNETized Kerr spacetime

Authors: Karthik Iyer, Chandrachur Chakraborty,

Comments: 24 pages, 8 figures,

Subjects: gr-qc astro-ph.HE

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

We study the orbital structure and precession dynamics of neutral test particles in the MAGNETized Kerr BLACK HOLE (MKBH) spacetime-an exact electrovacuum solution of the Einstein-Maxwell equations that self-consistently incorporates the curvature effects of an external MAGNETic field. This geometry allows a unified treatment of gravitational and MAGNETic influences across weak to ultra-strong regimes. The analysis reveals a critical MAGNETic field strength above which no circular geodesics, timelike or null, can exist, establishing an upper MAGNETic bound for orbital motion. For subcritical fields, the photon circular orbit admits two real roots, the outer of which defines an outermost stable circular orbit (OSCO), complementing the conventional innermost stable circular orbit (ISCO) and confining stable motion within a finite radial domain. Exact expressions for the orbital, radial, and vertical epicyclic frequencies, and their associated precession rates, show substantial deviations from Kerr behavior, including a MAGNETically induced reversal of periastron precession within a finite radial range. For astrophysically relevant MAGNETic field strengths, the retrograde precession could be observable at large radii around astrophysical BHs, offering a potential diagnostic of large-scale MAGNETization. These findings highlight the geometric influence of MAGNETic curvature on strong-field dynamics, providing a self-consistent framework to interpret quasi-periodic oscillation phenomenology and potential MAGNETic imprints in precision timing observations of compact objects.

[abstract 16 / 39] (score: 3)
arXiv:2510.13610 [pdf, ps, other]

Title: Solar Cycle Variation of Sustained Gamma-ray Emission Events from the Sun and Related Energetic Events

Authors: N. Gopalswamy, P. Mäkela, S. Akiyama, S. Yashiro, H. Xie,

Comments: 10 pages, 5 figures, 2 tables, Proc 17th workshop on Solar Influences on the Magnetosphere, Ionosphere and Atmosphere Primorsko, Bulgaria, June 2025

Subjects: astro-ph.HE astro-ph.SR

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

The sustained gamma ray emission (SGRE) from the Sun is one of the fascinating high energy phenomena closely related to the acceleration of protons to energies >300 MeV. Here we report on the solar cycle variation of SGRE events based on observations from FERMI's Large Area Telescope (LAT). This report covers solar cycles (SCs) 24 and 25 during which FERMI has been operating. Since SGRE events are closely related to solar energetic particle (SEP) events and interplanetary type II radio bursts caused by fast and wide coronal mass ejections (CMEs), we consider these phenomena as well. Many studies have shown that SC 25 is similar or slightly stronger than SC 24. The number of SEP events, GLE events, IP type II bursts, and fast and wide CMEs confirm this conclusion. However, the number of SGRE events observed by FERMI LAT has diminished significantly in SC 25 relative to SC 24. One of the issues has been the reduced coverage of the Sun since 2018 due to a mechanical problem with a solar array of the FERMI mission. By identifying the FERMI LAT gaps and the number of energetic events (fast and wide CMEs, interplanetary type II bursts) we conclude that about three times more SGRE events must have occurred than the 15 events observed by FERMI.

[abstract 17 / 39] (score: 3)
arXiv:2510.13737 [pdf, ps, other]

Title: Comparing subgrid models for COSMIC RAY diffusion in a MAGNETized isolated galaxy simulation

Authors: Sarah Thiele, Romain Teyssier,

Comments: Accepted version for MNRAS, 12 figures

Subjects: astro-ph.GA

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Galactic COSMIC RAYs (CRs) play a crucial role in galaxy formation and evolution by altering gas dynamics and chemistry across multiple scales. Typical numerical simulations of CR transport assume a constant diffusion coefficient for the entire galaxy, despite both numerical and theoretical studies showing that it can change by orders of magnitude depending on the phase of the interstellar medium. Only a few simulations exist that self-consistently calculate CR transport with diffusion, streaming, and advection by the background gas. In this study we explore three subgrid models for CR diffusion, based on popular theories of CR transport. We post-process an isolated, star-forming MHD galactic disk simulated using the RAMSES code. The resulting diffusion coefficients depend solely on the subgrid turbulent kinetic energy and the MHD state variables of the plasma. We use these models to calculate coefficients for vertical transport. We find that they depend critically on the local MAGNETic field tilt angle. Across models, our resulting diffusion coefficients range from $10^{26}~\rm cm^2s^{-1}$ to $10^{31}~\rm cm^2s^{-1}$, and yield CR energy densities at the midplane from $1$ to $100 ~\rm eV cm^{-3}$, suggesting varied degrees of backreaction on their environment. Using simple approximations, we show that the gamma ray luminosity of the galaxy depends primarily on the gas surface density and the turbulent confinement of CRs by the galactic corona.

[abstract 18 / 39] (score: 2)
arXiv:2407.18867 [pdf, ps, other]

Title: Catalog of outbursts of neutron star LMXBs

Authors: Craig O. Heinke, Junwen Zheng, Thomas J. Maccarone, Nathalie Degenaar, Arash Bahramian, Gregory R. Sivakoff, Simrat Toor,

Comments: Published in ApJS. 60 pages, 11 figures, 10 (very long) tables. Outbursts continue to be updated at https://tinyurl.com/5euncwmh ; please contact C Heinke (heinke@ualberta.ca) with missed outburst information

Subjects: astro-ph.HE

Created: 2025-10-11; Updated: 2025-10-16; Datestamp: 2025-10-16

Many X-ray binaries are transiently accreting. Having statistics on their recurrence times is helpful to address questions related to binary evolution and populations, as well as the physics of binary systems. We compile a catalog of known outbursts of 87 transient neutron star (identified through bursts or pulsations) low-mass X-ray binaries, until mid-2025. Most outbursts are taken from the literature, but we also identify some outbursts from public X-ray monitoring lightcurves. We find 109 outbursts not previously identified in the literature; most are from the frequent transients GRS 1747-312 and the Rapid Burster MXB 1730-335, though we suspect that two outbursts from Liller 1 may be from another transient, besides the Rapid Burster. We also find new outbursts for 10 other systems, and verify substantial quiescent intervals for XMM J174457-2850.3, XMMU J174716.1-281048, and AX J1754.2-2754. Outburst detection has been relatively efficient since 1996 for outbursts above $F_X$(2-10)$=3\times10^{-10}$ ergs/s/cm$^2$. While several systems have many known outbursts, 40 of the 87 systems we track have zero or one recorded outburst between 1996 and 2023. This suggests that many faint Galactic Center X-ray binaries may be neutron star X-ray binaries, though we cannot completely rule out the proposition that most neutron star X-ray binaries undergo frequent outbursts below all-sky monitor detection limits.

[abstract 19 / 39] (score: 2)
arXiv:2504.13313 [pdf, ps, other]

Title: Machine-learning Closure for Vlasov-Poisson Dynamics in Fourier-Hermite Space

Authors: Nathaniel Barbour, William Dorland, Ian G. Abel, Matt Landreman,

Comments: Updated version that was accepted for publication in Journal of Plasma Physics. Includes a new section, appendix, and four new figures. 24 pages, 15 figures, 1 table in total

Subjects: physics.plasm-ph

Created: 2025-10-14; Updated: 2025-10-16; Datestamp: 2025-10-16

Accurate reduced models of turbulence are desirable to facilitate the optimization of MAGNETic-confinement fusion reactor designs. As a first step toward higher-dimensional turbulence applications, we use reservoir computing, a machine-learning (ML) architecture, to develop a closure model for a limiting case of electrostatic gyrokinetics. We implement a pseudo-spectral Eulerian code to solve the one-dimensional Vlasov-Poisson system on a basis of Fourier modes in configuration space and Hermite polynomials in velocity space. When cast onto the Hermite basis, the Vlasov equation becomes an infinitely coupled hierarchy of fluid moments, presenting a closure problem. We exploit the locality of interactions in the Hermite representation to introduce an ML closure model of the small-scale dynamics in velocity space. In the linear limit, when the kinetic Fourier-Hermite solver is augmented with the reservoir closure, the closure permits a reduction of the velocity resolution, with a relative error within two percent for the Hermite moment where the reservoir closes the hierarchy. In the strongly-nonlinear regime, the ML closure model more accurately resolves the low-order Fourier and Hermite spectra when compared to a naïve closure by truncation and reduces the required velocity resolution by a factor of sixteen.

[abstract 20 / 39] (score: 2)
arXiv:2504.14190 [pdf, ps, other]

Title: Matter Dipole and Hubble Tension due to Large Wavelength Perturbations

Authors: Gopal Kashyap, Naveen K. Singh, Pankaj Jain,

Comments: 11 pages, 6 figures

Subjects: astro-ph.CO

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

We theoretically analyze the dipole anisotropy observed in the QUASAR distribution from the CatWISE2020 catalog. The catalog data shows a peak around $z\approx 1$, suggesting the presence of a large-scale dipole component. We explore the possibility that this dipole could be driven by primordial density fluctuations from modes that were superhorizon at the time of CMB decoupling but have since entered the horizon and become subhorizon. In particular, we consider the impact of adiabatic modes with wave numbers $k$ in the range $(10^{-4} - 4 \times 10^{-3})~\mathrm{Mpc}^{-1} $, corresponding to wavelength scales of several Gpc. Such modes can create large-scale density variations, likely causing anisotropies in the distribution of matter and, as a result, affecting the number density of observed QUASARs. We find that these can lead to a significant contribution to the dipole for sources up to redshifts of about 1, but are unable to explain the observed dipole. We also demonstrate that a superhorizon curvature perturbations mode, with a comoving wavenumber $k\lesssim0.3H_0$ can lead to a significant enhancement in the locally inferred Hubble constant. This effect offers a viable explanation for the observed discrepancy between local and CMB inferred measurements of $H_0$.

[abstract 21 / 39] (score: 2)
arXiv:2505.13883 [pdf, ps, other]

Title: Influence of ambient temperature on cavitation bubble dynamics

Authors: Shaocong Pei, A-Man Zhang, Chang Liu, Tianyuan Zhang, Rui Han, Shuai Li,

Comments:

Subjects: physics.flu-dyn

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

We investigate the influence of ambient temperature on the dynamics of spark-generated cavitation bubbles over a broad temperature range of 23 to 90$^\circ \text{C}$. Increasing temperature, the attenuation of collapse intensity of a bubble in a free field is quantitatively characterised through the Rayleigh factor, minimum bubble volume, and maximum collapse velocity. In scenarios where the bubble is initiated near a rigid boundary, this temperature-dependent weakening effect manifests further as a reduction in JET velocity and bubble migration. Additionally, our findings demonstrate that when ambient temperature exceeds 70$^\circ \text{C}$, secondary cavitation forms near the bubble surface around the moment of maximum bubble expansion, followed by coalescence-induced surface wrinkles. These perturbations trigger Rayleigh-Taylor instability and enhance bubble fission. We determine the internal gas pressure of the bubble at its maximum expansion via the Rayleigh-Plesset equation with the input of bubble radius from experimental measurements. It reveals that the secondary cavitation is derived from the gas pressure descending below the saturated vapor pressure, which provides nucleation-favorable conditions. This study sheds light on the physics behind erosion mitigation in high-temperature fluids from the perspective of cavitation bubble dynamics.

[abstract 22 / 39] (score: 2)
arXiv:2506.00907 [pdf, ps, other]

Title: Lattice Boltzmann Boundary Conditions for Flow, Convection-Diffusion and MHD Simulations

Authors: Jun Li, Wai Hong Ronald Chan, Zhe Feng, Chenglei Wang,

Comments: 1. General derivation of LBM schemes for Dirichlet, Neumann and Robin-like boundaries; 2. Simple interpolation or extrapolation scheme for arbitrary boundary-to-grid distances; 3. Boundary schemes valid for both flat and curved boundaries; 4. Boundary schemes valid for both static and moving boundaries; 5. Boundary schemes compatible in fully coupled simulations of multi-physics

Subjects: physics.comp-ph physics.flu-dyn

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

A general derivation is proposed for several boundary conditions arisen in the lattice Boltzmann simulations of various physical problems. Pair-wise moment conservations are proposed to enforce the boundary conditions with given macroscopic quantities, including the velocity and pressure in flow simulations, concentration in convection-diffusion (CD) simulations, as well as MAGNETic field components in MAGNETohydrodynamical (MHD) simulations. Additionally, the CD and MHD simulations might involve the Robin boundary condition for surface reactions and a Robin-like boundary condition for thin walls with finite electrical conductivities, respectively, both of which can be written in a form with a variable flux term. In this case, the proposed boundary scheme takes the flux term as an increment to the bounced distribution function and a reference frame transformation is used to obtain a correction term for moving boundaries. Spatial interpolation and extrapolation are used for arbitrary boundary locations between computational grid points. Due to using the same approach in derivations, the obtained boundary schemes for different physical processes in a coupled simulation are compatible for arbitrary boundary-to-grid distances (not limited to the popular half-grid boundary layout) and arbitrary moving speeds. Simulations using half-grid and full-grid boundary layouts for flat boundaries are conducted for demonstrations and validations. Moving boundaries are simulated in hydrodynamic and MHD flows, while static boundaries are used in the CD simulations with surface reactions. The numerical and analytical solutions are in excellent agreement in the studied cases. The proposed boundary schemes are also applied in simulating fully coupled MHD pipe flows of a curved boundary with various boundary-to-grid distances and excellent agreement with analytical solutions is also obtained.

[abstract 23 / 39] (score: 2)
arXiv:2507.17621 [pdf, ps, other]

Title: Chaotic/turbulent cross-helical MHD dynamo: from laboratory to the Sun

Authors: A. Bershadskii,

Comments: Extended (new data have been added)

Subjects: physics.flu-dyn

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Using the results of laboratory experiments and direct numerical simulations, as well as observations of the full-disc solar MAGNETic field and sunspot number dynamics, it is demonstrated that cross-helicity can dominate the frequency power spectra of the MAGNETic field generated by a MAGNETohydrodynamic (MHD) dynamo in chaotic/turbulent swirling flows. The theoretical consideration is based on a Kolmogorov-like phenomenology within the framework of the distributed chaos concept. It is shown that the solar full-disc MAGNETic field for the last two solar cycles with weak MAGNETic activity exhibits deterministic chaotic behavior concentrated around the equator. There is also observational indication that for the past periods of strong solar MAGNETic activity, there are two regimes of the smooth chaotic (but non-deterministic) cross-helical dynamo (high frequency and low frequency) separated by the 11-year phenomenon.

[abstract 24 / 39] (score: 2)
arXiv:2510.01376 [pdf, ps, other]

Title: Quasinormal ringing and Unruh-Verlinde temperature of the Frolov Black Hole

Authors: Akshat Pathrikar,

Comments: 14 pages, 11 figures, 8 tables

Subjects: gr-qc astro-ph.GA

Created: 2025-10-14; Updated: 2025-10-16; Datestamp: 2025-10-16

In this study, we investigate electroMAGNETic and Dirac field axial-perturbations of a charged regular BLACK HOLE arising from quantum gravity effects, commonly referred to as the Frolov BLACK HOLE, a regular (nonsingular) BLACK HOLE solution. We derive the master wave equations for massless electroMAGNETic and Dirac perturbations and solve them using the standard Wentzel-Kramers-Brillouin (WKB) method along with Padé approximation. From these solutions, we extract the dominant and overtone quasinormal mode (QNM) frequencies along with the associated grey-body factors, highlighting the deviations introduced by quantum gravity corrections compared to the classical case of Reissner-Nordström BLACK HOLE. Furthermore, we analyze the Unruh-Verlinde temperature of this spacetime, providing quantitative estimates of how quantum gravity effects influence both quasinormal ringing and particle emission in nonsingular BLACK HOLE models.

[abstract 25 / 39] (score: 2)
arXiv:2510.09437 [pdf, ps, other]

Title: Long Living Hot and Dense Plasma from Relativistic Laser-Nanowire Array Interaction

Authors: Ehsan Eftekhari-Zadeh, Mikhail Gyrdymov, Parysatis Tavana, Robert Loetzsch, Ingo Uschmann, Thomas Siefke, Thomas Käsebier, Uwe Zeitner, Adriana Szeghalmi, Alexander Pukhov, Dmitri Serebryakov, Evgeni Nerush, Igor Kostyukov, Olga Rosmej, Christian Spielmann, Daniil Kartashov,

Comments:

Subjects: physics.plasm-ph hep-ex physics.optics

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Long-living, hot and dense plasmas generated by ultra-intense LASER beams are of critical importance for LASER-driven nuclear physics, bright hard X-ray sources, and laboratory astrophysics. We report the experimental observation of plasmas with nanosecond-scale lifetimes, near-solid density, and keV-level temperatures, produced by irradiating periodic arrays of composite nanowires with ultra-high contrast, RELATIVISTICally intense femtosecond LASER pulses. Jet-like plasma structures extending up to 1~mm from the nanowire surface were observed, emitting K-shell radiation from He-like Ti$^{20+}$ ions. High-resolution X-ray spectra were analyzed using 3D Particle-in-Cell (PIC) simulations of the LASER-plasma interaction combined with collisional--radiative modeling (FLYCHK). The results indicate that the JETs consist of plasma with densities of $10^{20}$-$10^{22}$ cm$^{-3}$ and keV-scale temperatures, persisting for several nanoseconds. We attribute the formation of these JETs to the generation of kiloTesla-scale global MAGNETic fields during the LASER interaction, as predicted by PIC simulations. These fields may drive long-timescale current instabilities that sustain MAGNETic fields of several hundred tesla, sufficient to confine hot, dense plasma over nanosecond durations.

[abstract 26 / 39] (score: 2)
arXiv:2510.11180 [pdf, ps, other]

Title: Tuning Layer Orbital Hall Effect via Spin Rotation in FerroMAGNETic Transition Metal Dichalcogenides

Authors: Shilei Ji, Jianping Yang, Li Gao, Xing'ao Li,

Comments:

Subjects: physics.comp-ph

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Orbitronics, which leverages the angular momentum of atomic orbitals for information transmission, provides a novel strategy to overcome the limitations of electronic devices. Unlike electron spin, orbital angular momentum (OAM) is strongly influenced by crystal field effects and band topology, making its orientation difficult to manipulate with external fields. In this work, by using first principle calculations, we investigate quantum anomalous Hall insulators (QAHIs) as a model system to study the layer orbital Hall effect (OHE). Due to band inversion, only one valley remains orbital POLARIZATION, and thus the OHE originates from a single valley. Based on stacking symmetry analysis, we investigated both AA and AB stacking configurations, which possess mirror and inversion symmetries, respectively. The excitation of OAM exhibits valley selectivity, determined jointly by valley POLARIZATION and orbital POLARIZATION. In AA stacking, the absence of inversion center gives rise to intrinsic orbital POLARIZATION, leading to OAM excitations from different valleys in the two layers. In contrast, AB stacking is protected by inversion symmetry, which enforces valley POLARIZATION and causes OAM in both layers to originate from the same valley. Furthermore, the direction of spin POLARIZATION tunes the sign of the Berry curvature, thereby dictating the transport of OAM. As a result, in bilayer antiferroMAGNETic QAHI systems, orbital currents display a distinct layer-contrasting behavior in both flow direction and OAM accumulation.

[abstract 27 / 39] (score: 2)
arXiv:2510.11790 [pdf, ps, other]

Title: False Alarm Rates in Detecting Gravitational Wave Lensing from Astrophysical Coincidences: Insights with Model-Independent Technique GLANCE

Authors: Aniruddha Chakraborty, Suvodip Mukherjee,

Comments: 18 pages, 10 figures (including appendices)

Subjects: gr-qc astro-ph.CO astro-ph.GA astro-ph.HE

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

The strong lensing gravitational waves (GWs) due to intervening massive astrophysical systems between the source and an observer are an inevitable consequence of the general theory of relativity, which can produce multiple GW events in overlapping sky localization error. However, the confirmed detection of such a unique astrophysical phenomenon is challenging due to several sources of contamination, arising from detector noise to astrophysical uncertainties. Robust model-independent search techniques that can mitigate noise contamination were developed in the past. In this study, we explore the astrophysical uncertainty associated with incorrectly classifying a pair of unlensed GW events as a lensed event, and the associated False Alarm Rate (FAR) depending on the GW source properties. To understand the effect of unlensed astrophysical GW sources in producing false lensing detections, we have performed a model-independent test using the pipeline GLANCE on a simulated population of merging binary-BLACK HOLEs (BBHs). We find that $\sim$ 0.01\% of the event pairs can be falsely classified as lensed with a lensing threshold signal-to-noise ratio of 1.5, appearing at a time delay between the event pairs of $\sim$ 1000 days or more. We show the FAR distribution for the parameter space of GW source masses, delay time, and lensing magnification parameter over which the model-independent technique GLANCE can confidently detect lensed GW pair with the current LIGO detector sensitivity. In the future, this technique will be useful for understanding the FAR of the upcoming next-generation GW detectors, which can observe many more GW sources.

[abstract 28 / 39] (score: 2)
arXiv:2510.11861 [pdf, ps, other]

Title: Impact of facility timing and coordination for next-generation gravitational-wave detectors

Authors: Ssohrab Borhanian, Arianna Renzini, Philippa S. Cole, Costantino Pacilio, Michele Mancarella, Davide Gerosa,

Comments: 29 pages, 8 figures, 3 tables

Subjects: gr-qc astro-ph.HE

Created: 2025-10-13; Updated: 2025-10-16; Datestamp: 2025-10-16

While the Einstein Telescope and Cosmic Explorer proposals for next-generation, ground-based detectors promise vastly improved sensitivities to gravitational-wave signals, only joint observations are expected to enable the full scientific potential of these facilities, making timing and coordination between the efforts crucial to avoid missed opportunities. This study investigates the impact of long-term delays on the scientific capabilities of next-generation detector networks. We use the Fisher information formalism to simulate the performance of a set of detector networks for large, fiducial populations of binary BLACK HOLEs, binary neutron stars, and primordial black-hole binaries. Bootstrapping the simulated populations, we map the expected observation times required to reach a number of observations fulfilling scientific targets for key sensitivity and localization metrics across various network configurations. We also investigate the sensitivity to stochastic backgrounds. We find that purely sensitivity-driven metrics such as the signal-to-noise ratio are not strongly affected by delays between facilities. This is contrasted by the localization metrics, which are very sensitive to the number of detectors in the network and, by extension, to delayed observation campaigns for a detector. Effectively, delays in one detector behave like network-wide interruptions for the localization metrics for networks consisting of two next-generation facilities. We examine the impact of a supporting, current-generation detector such as LIGO India operating concurrently with next-generation facilities and find such an addition will greatly mitigate the negative effects of delays for localization metrics, with important consequences on multi-messenger science and stochastic searches.

[abstract 29 / 39] (score: 2)
arXiv:2510.12855 [pdf, ps, other]

Title: Differential topology and micro-structure of BLACK HOLE in Einstein-Euler-Heisenberg spacetimes with exponential entropy

Authors: Muhammad Yasir, Tong Lining, Kazuharu Bamba,

Comments:

Subjects: gr-qc

Created: 2025-10-14; Updated: 2025-10-16; Datestamp: 2025-10-16

Exact BLACK HOLEs in the Einstein Euler-Heisenberg theory are explored with an exponential entropy framework by using the topological current $Ψ$-mapping theory. The topology classes are investigated through the canonical, mixed, and grand canonical ensembles. In particular, the MAGNETic charge is fixed for the canonical ensemble, whereas the MAGNETic potential is included for the mixed ensemble and the grand canonical ensemble with maintaining its consistency through the MAGNETic potential. The topological charges are analyzed for each ensemble through critical points. As a result, it is found that the canonical, mixed, and grand canonical ensembles lead to either $1$, $-1$, or no generation/annihilation points. Moreover, it is shown how temperature and heat capacity depend on the horizon radius in order to verify the stability of a BLACK HOLE. Furthermore, the behavior of the thermodynamic curvatures of a BLACK HOLE is investigated through the geometric methods.

[abstract 30 / 39] (score: 2)
arXiv:2510.12877 [pdf, ps, other]

Title: Dark Matter-Electron Interactions Alter the Luminosity and Spectral Index of M87

Authors: Abdelaziz Hussein, Gonzalo Herrera,

Comments: 6+6 pages, 3+2 figures. Comments are welcome

Subjects: hep-ph astro-ph.CO astro-ph.HE

Created: 2025-10-14; Updated: 2025-10-16; Datestamp: 2025-10-16

We investigate the possibility that cosmic-ray electron cooling through DARK MATTER-electron scatterings contributes to the low radiative efficiency observed in radio-loud galaxies such as M87. Light DARK MATTER can scatter efficiently off electrons in M87, lowering the observed bolometric luminosity compared to astrophysical expectations. This consideration allows us to probe previously unexplored regions of the parameter space of DARK MATTER-electron interactions. We further model the cosmic-ray electron distribution by numerically solving a diffusion equation along the JET and find that efficient DARK MATTER-electron interactions can induce a flattening of the spectral index at different distances from the central supermassive BLACK HOLE, in better alignment with radio observations from M87.

[abstract 31 / 39] (score: 2)
arXiv:2510.13066 [pdf, ps, other]

Title: Gravitational-Wave Signatures of Highly Eccentric Stellar-Mass Binary Black Holes in Galactic Nuclei

Authors: Evgeni Grishin, Isobel M. Romero-Shaw, Alessandro A. Trani,

Comments: MNRAS submitted, comments welcome!

Subjects: astro-ph.HE gr-qc

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

A significant fraction of compact-object mergers in galactic nuclei are expected to be eccentric in the Laser-Interferometer-Space-Antenna (LISA) frequency sensitivity range, $10^{-4} - 10^{-1}\ \rm Hz$. Several compact binaries detected by the LIGO-Virgo-KAGRA Collaboration may retain hints of residual eccentricity at $10$~Hz, suggesting dynamical or triple origins for a significant fraction of the gravitational-wave-observable population. In triple systems, von-Zeipel-Lidov-Kozai oscillations perturb both the eccentricity and the argument of pericentre, $ω$, of the inner BLACK HOLE binary. The latter could be fully \textit{circulating}, where $ω$ cycles through $2π$, or may \textit{librate}, with $ω$ ranges about a fixed value with small or large variation. We use \texttt{TSUNAMI}, a regularised N-body code with up to 3.5 post-Newtonian (PN) term corrections, to identify four different families of orbits: (i) circulating, (ii) small and (iii) large amplitude librating, and (iv) merging orbits. We develop and demonstrate a new method to construct gravitational waveforms using the quadrupole formula utilising the instantaneous {\it total} acceleration of each binary component in \texttt{TSUNAMI}. We show that the four orbital families have distinct waveform phenomenologies, enabling them to be distinguished if observed in LISA. The orbits are also distinguishable from an isolated binary or from a binary perturbed by a different tertiary orbit, even if the secular timescale is the same. Future burst timing models will be able to distinguish the different orbital configurations. For efficient binary formation, about $\sim 50$ binaries can have librating orbits in the Galactic Centre.

[abstract 32 / 39] (score: 2)
arXiv:2510.13073 [pdf, ps, other]

Title: The broken link between space and time in elastic turbulence

Authors: Giulio Foggi Rota, Rahul K. Singh, Alessandro Chiarini, Christian Amor, Giovanni Soligo, Dhrubaditya Mitra, Marco Edoardo Rosti,

Comments: 14 pages, 6 figures

Subjects: physics.flu-dyn

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Elastic turbulence (ET), observed in flows of sufficiently elastic polymer solution at small inertia, is characterized by chaotic motions and power-law scaling of energy spectrum ($E$) in both wavenumber ($k$) and frequency ($ω$): $E(k) \sim k^{-α}$ and $E(ω) \sim ω^{-β}$. Experiments of ET have obtained a vast range of values for the exponent $β$. In inertial turbulence, Taylor's frozen-flow hypothesis implies $α= β$, i.e., spatial and temporal scales are linearly related to each other. In contrast, from high-resolution simulation in three different setups, a tri-periodic box, a channel, and a planar JET, we show that in ET $α\approx 4$ while $β$ varies significantly. Our analysis shows that in general Taylor's hypothesis does not hold in ET as there is no universal relation, linear or otherwise, between space and time. Thus, we clear the confusion of the different scaling exponents found in ET, and focus the attention of future research on understanding $α$. We introduce a fundamentally new way of looking not only at polymeric turbulence, but also at smooth chaotic flows in general, e.g., active turbulence.

[abstract 33 / 39] (score: 2)
arXiv:2510.13294 [pdf, ps, other]

Title: Global linear analysis of the MAGNETo-thermal instability in a stratified spherical model of the intracluster medium

Authors: J. M. Kempf, H. Latter,

Comments: 20 pages, 6 figures, accepted for publication in A&A, arXiv abstract slightly shortened

Subjects: astro-ph.CO astro-ph.HE

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

The buoyancy stability properties of the ICM are modified because of the anisotropic transport of heat along the MAGNETic field lines. This feature gives rise to the MTI when the temperature gradient is aligned with the gravity, which occurs in the outskirts of galaxy clusters. Most previous linear analyses of the MTI adopted a local, Boussinesq approach. However, the conduction length, which sets the characteristic length scale of the MTI, might be a non-negligible fraction of the scale height in the ICM. We want to assess the impact of locality assumptions on the linear physics of the MTI. Another goal is to unveil the deeper connections between these global MTI modes and their MRI counterparts in accretion discs. Our third objective is to provide a new benchmark against which any numerical code implementing the Braginskii heat flux in spherical geometry can be tested. We perform a global linear analysis of the MTI in a spherical stratified model of the ICM. We use a combination of analytical results, corroborated by numerical results obtained with both a pseudo-spectral solver and IDEFIX, to better explain the physics of the global MTI modes. We obtain scaling laws and approximate expressions for the growth rates of the global modes. We show that the associated functions are confined within an inner region, limited by a turning point, where the mode is allowed to grow. The most unstable local MTI modes correspond to the portion of the global mode localised near the turning point. This phenomenology is similar to that of the global MRI modes. Finally, direct simulations successfully reproduce the global MTI modes and their growth rates, with errors smaller than 1%. Overall, this study provides us with new insights on the linear theory of the global MTI in the ICM, and a useful numerical test bench for any astrophysical fluid dynamics code embedding anisotropic heat flux.

[abstract 34 / 39] (score: 2)
arXiv:2510.13482 [pdf, ps, other]

Title: Low-impedance stripline kicker for the transverse instability suppression system of the SYNCHROTRON radiation facility "SKIF" light source

Authors: M. A. Baistrukov, E. A. Bekhtenev, A. A. Krasnov, D. A. Nikiforov, P. A. Piminov,

Comments: 14 pages, 7 figures

Subjects: physics.acc-ph

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Construction of the new fourth generation SYNCHROTRON radiation facility (SRF) "SKIF" near Novosibirsk is nearing completion. "SKIF" uniqueness is ultra-low 75 pm natural emittance at 400 mA beam current and 3 GeV beam energy. Collective effects (beam interaction with the vacuum chamber) are the main obstacles of achieving such emittance and beam current. To suppress these effects the storage ring will be equipped with a bunch-by-bunch feedback system. Important components of the feedback system are a stripline (fast) kicker and a beam position monitor. The paper describes design of the low-impedance stripline kicker for SRF "SKIF" storage ring, optimized for the manufacturing and for the uniformity of the imparted transverse kick. The kicker qualities such as S-parameters, imparted transverse momentum, transfer and beam impedances are presented. The chosen length of the stripline kicker allows its use as a beam position monitor.

[abstract 35 / 39] (score: 2)
arXiv:2510.13533 [pdf, ps, other]

Title: The Formation Rate and Luminosity Function of Fast X-ray transients from Einstein probe

Authors: Yizhou Guo, Houdun Zeng, Junjie Wei, Hao Zhou, Zhiping Jin, Xuefeng Wu, Daming Wei,

Comments: 9 pages, 4 figures, and 1 table

Subjects: astro-ph.HE hep-ph

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Following its launch on January 9, 2024, the Einstein Probe (EP) telescope has detected hundreds of fast X-ray transients (FXTs), yet their physical origins remain elusive. Understanding their luminosity function and formation rate is crucial for elucidating their nature. Based on the latest catalog of EP-detected FXTs, we present, a model-independent, non-parametric approach to derive the luminosity function and formation rate of FXTs. Our analysis reveals significant cosmological luminosity evolution, characterized by a scaling relationship of $(1+z)^{3.58}$. After accounting for this evolution, we establish that the local luminosity function is best represented by a broken power law, with a break luminosity of $(4.17 \pm 0.34) \times 10^{46}$ erg/s. The formation rate exhibits a gentle decline with redshift, following the relation $(1+z)^{-0.21}$, yielding a local rate of approximately $28.0_{-16.4}^{+27.3}$ Gpc$^{-3}$ yr$^{-1}$. This rate is comparable to that of low-luminosity long GAMMA-RAY BURSTs (LGRBs). Our findings indicate a potential correlation between FXTs and LGRBs, supporting the majority of FXTs may be linked to collapsar progenitors.

[abstract 36 / 39] (score: 2)
arXiv:2510.13552 [pdf, ps, other]

Title: Probing thermodynamic phase transitions by dynamics of timelike particle around a MAGNETic AdS BLACK HOLE

Authors: R. H. Ali, Zi-Yu Tang, Xiao-Mei Kuang,

Comments: 17pages

Subjects: gr-qc hep-th

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

In this paper, we investigate the phase structure of a nonminimal coupled MAGNETic AdS BLACK HOLE by connecting its thermodynamic properties with the dynamical behavior of orbiting particles, within the framework of Lyapunov exponent and quasi-periodic oscillation. The analysis of the free energy as a function of the Hawking temperature reveals a Van der Waals-like phase transition, characterized by the coexistence of small, intermediate, and large BLACK HOLE phases. By examining timelike geodesics corresponding to unstable circular orbits, we evaluate the Lyapunov exponent of the test particles crossing the phase transition and explore its role as dynamical indicator of stability. Furthermore, by perturbing the unstable circular orbit and employing the RELATIVISTIC precession model, we explore the associated upper and lower quasi-periodic oscillation frequencies. Our findings show that the occurrence of thermodynamic phase transitions induces marked changes in both Lyapunov exponent and quasi-periodic oscillation spectra, indicating that these dynamical quantities can serve as sensitive probes of the underlying thermodynamic phase structure of the BLACK HOLE.

[abstract 37 / 39] (score: 2)
arXiv:2510.13736 [pdf, ps, other]

Title: The collision and merger products of stars do not look alike: A MAGNETohydrodynamics comparison

Authors: Pavan Vynatheya, Taeho Ryu, Chen Wang, Alison Sills, Rüdiger Pakmor,

Comments: 16 pages, 7 figures, 3 tables, Submitted to ApJ

Subjects: astro-ph.SR astro-ph.HE

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

A significant fraction of stars experience close interactions, including collisions resulting from gravitational encounters and mergers within close binary systems. These processes can produce more massive stars that may give rise to relatively rare objects such as blue stragglers. Distinguishing the outcomes of collisions and mergers is challenging yet essential for interpreting observations. This study utilizes the MAGNETohydrodynamics code AREPO to simulate collisions and mergers of $5$ to $10 \,\mathrm{M}_{\odot}$ main-sequence stars, systematically comparing the properties of the resulting products. Both collisions and mergers yield more massive, strongly MAGNETized, rapidly and differentially rotating stars with cores enriched in hydrogen, but notable quantitative differences emerge. Merger products exhibit core hydrogen fractions up to $10\%$ higher than those of collision products. In both scenarios, turbulent mixing amplifies MAGNETic field energies by $9$ to $12$ orders of magnitude. However, MAGNETic fields in small-impact-parameter collision products display small-scale reversals that may dissipate over time, whereas merger products and large-impact-parameter collision products develop large-scale ordered, potentially long-lived MAGNETic fields. Additionally, only merger products display MAGNETically driven, bipolar outflows with radial velocities exceeding $300$ to $400 \,\mathrm{km}\,\mathrm{s}^{-1}$. These distinctions may result in divergent long-term evolutionary outcomes, which warrant further investigation in future studies.

[abstract 38 / 39] (score: 2)
arXiv:2510.13739 [pdf, ps, other]

Title: XRISM Resolves Relativistic Effects from the Innermost Accretion Disk in Serpens X-1

Authors: R. M. Ludlam, J. M. Miller, E. M Cackett, J. A. Garcia,

Comments: 10 pages, 4 figures, 2 tables, accepted for publication in ApJL

Subjects: astro-ph.HE

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

We present the first XRISM/Resolve observation of the persistently accreting neutron star (NS) low-mass X-ray binary Serpens X-1. The source was observed on October 17th, 2024, for approximately 350 ks of elapsed time, resulting in 171 ks of exposure. The source exhibited 22% variability with respect to the average count rate of 73.1 count/s during the observation, but remained in a spectrally soft state throughout. The time averaged spectrum was analyzed in conjunction with spectra extracted from periods of different count rate to check for variations in spectral components. The unprecedented energy resolution of 4.5 eV at 6 keV of XRISM/Resolve provides a detailed look at the shape and structure of the Fe emission line within the data, which shows a dual-peaked structure with an extended red-wing, and steep decline in the blue-wing of the line profile. Fits with the reflection model relxillNS are able to describe the structure in the Fe line region, and confirms previous results that the disk is close to the NS ($R_{\rm in}$ = $1.02_{-0.01}^{+0.21}\ R_{\rm ISCO}$). These models also measure a low systemic inclination ($i=5^{\circ}\pm1^{\circ}$), confirming prior X-ray and optical studies. Alternative models were explored to describe the structure of the Fe line profile, however, RELATIVISTIC reflection provides the simplest and statistically best explanation of the data.

[abstract 39 / 39] (score: 2)
arXiv:2510.13788 [pdf, ps, other]

Title: Investigating double bump air showers with the SKA-Low

Authors: V. De Henau, S. Bouma, J. Bray, S. Buitink, A. Corstanje, M. Desmet, E. Dickinson, L. van Dongen, B. Hare, H. He, J. R. Hörandel, T. Huege, C. W. James, M. Jetti, P. Laub, H. -J. Mathes, K. Mulrey, A. Nelles, O. Scholten, C. Sterpka, S. ter Veen, K. Terveer, P. Turekova, T. N. G. Trinh, S. Saha, S. Sharma, R. Spencer, D. Veberič, K. Watanabe, M. Waterson, C. Zhang, P. Zhang, Y. Zhang,

Comments: Presented at the 39th International Cosmic Ray Conference (ICRC 2025). 9 pages, 6 figures

Subjects: astro-ph.HE

Created: 2025-10-15; Updated: 2025-10-16; Datestamp: 2025-10-16

Double-bump showers are a rare class of extensive air showers (EAS) predicted by Monte Carlo simulations. They occur when a high-energy secondary particle, the leading particle, travels significantly farther than the rest, creating a distinct double-peaked longitudinal profile. So far, no experiment has been able to directly detect these showers. The unique radio footprint of double-bump showers, characterized by multiple Cherenkov rings, provides a way to reconstruct longitudinal profiles from radio observations. With its dense antenna array and broad frequency range, the Square Kilometer Array Observatory (SKAO) will be the first experiment capable of detecting these features, offering a new opportunity to probe hadronic interactions and constrain particle cross sections at high energies. In our analysis, we simulate the EAS using CORSIKA with the CoREAS plugin for radio. We developed a new method based on the Akaike information criterion to identify double bump showers in simulations by analyzing their longitudinal profiles. Then we investigate the prevalence of these double bump showers across different COSMIC RAY primary particles and various hadronic interaction models. We create a skeleton of the EAS which consists of all the particles with at least $1\%$ of the primary energy, allowing us to confirm the leading particle hypothesis and track shower development following these particles. This will enable us to relate the attributes of the leading particle to measurable parameters. Depending on the exact shower properties, the radio footprint of a double bump shower can create a complex interference pattern, consisting of multiple rings. From this information, the longitudinal profiles can be extracted. SKA due to its dense antenna array and frequency range will be the first experiment able to observe these double bump showers in detail.