Current date: 2026-08-03
Setting default datestamp limit: 0
Datestamp limit: 2026-08-03 (0 days ago)
Created/updated limit: 2026-07-27 (7 days ago)
Found keywords_cs.datFound keywords_cis.dat
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=2026-08-03&until=2026-08-03&set=physics&metadataPrefix=arXiv
Scoring abstracts
Number of records retrieved: 171
Keyword score statistics
score 6 -- 2 abstracts
score 5 -- 1 abstracts
score 4 -- 2 abstracts
score 3 -- 2 abstracts
score 2 -- 6 abstracts
in total -- 13 abstracts
Articles that appeared on 2026-08-03
-
[abstract 1 / 13] Yes (score: 6)
- Title: Peering through the dip: IXPE unveils the extended scattering environment of GX 13+1Authors: Alessandro Di Marco, Fabio La Monaca, Luigi Stella, Anagha P. Nitindala, Alexandra Veledina, Anna Bobrikova, Eleonora Veronica Lai, Alessandro Papitto, Maura Pilia, Juri Poutanen, Daniele Rogantini, Matteo Bachetti, Maria Cristina Baglio, Caterina Ballocco, Ettore Del Monte, Wei Deng, Giulia Illiano, Vladislav Loktev, Sara Motta, Fei Xie,Comments: Submitted on A&ASubjects: astro-ph.HECreated: 2026-07-30; Updated: 2026-08-03; Datestamp: 2026-08-03
Neutron star low-mass X-ray binaries feature complex accretion geometries, often including an accretion disk corona or disk winds. Here, a study of the highly inclined dipping source GX 13+1, using coordinated observations from the IXPE, NUSTAR, and SWIFT-XRT, is presented; this is the first time that such a campaign was conducted to monitor its periodic dip. Our analysis reveals significant variations in polarimetric properties tracking the dip. At the center of the dip, the POLARIZATION degree reaches a maximum of ${\sim}$9% (at more than $8σ$ confidence level). This is accompanied by a highly significant POLARIZATION angle rotation of roughly 60$^\circ$ when passing from the dip to the subsequent off-dip state. Furthermore, the dip state exhibits energy-dependent POLARIZATION. By modeling the POLARIZATION during the periodic dip, we constrain the geometry of the scattering medium. In the scenario of an oblate extended accretion disk corona (ADC), an equatorial radius at least 1.5 times its polar radius is needed with $τ{\sim}0.3$. Alternatively, the results can be modeled as scattering in a disk wind with a most probable electron density of $1.3\times10^{14}$ cm$^{-3}$ and an opening angle near 40$^\circ$, corresponding to an optical depth of ${\sim}0.2$. The obtained results highlight the crucial role of X-ray polarimetric data to unveil the geometry of the extended scattering environment surrounding the accretion disks, advancing our understanding of neutron star low-mass X-ray binaries.
[abstract 2 / 13] Yes (score: 6) - Title: Strongly Magnetized Super-Eddington Accretion: How Spin and Accretion Rate Regulate Energy Output and Mass LossAuthors: Tom Man Kwan, Lixin Dai, Cheuk Kwan Kan, Zepei Xing, Tassos Fragos, Matthew Middleton, Tao Ji, Feng Yuan,Comments: 15 main figures, 4 tables, submittedSubjects: astro-ph.HECreated: 2026-07-31; Updated: 2026-08-03; Datestamp: 2026-08-03
Strongly MAGNETized super-Eddington accretion flows power many important astrophysical systems, but how BLACK HOLE parameters control their output is unclear. We present 32 general RELATIVISTIC radiation MAGNETohydrodynamics simulations of super-Eddington MAGNETically arrested disks onto stellar-mass BLACK HOLEs, varying mass ($M_{\rm BH}= 5, 15, 30\,M_{\odot}$), spin ($a=0,0.9$), and accretion rate ($\dot{M}_{\rm acc} \approx 1-2000\,\dot{M}_{\rm Edd}$). We find that BLACK HOLE spin and accretion rate jointly regulate wind loss rates and energy output efficiencies, while BLACK HOLE mass has no effect over the mass range studied here. The BH accretes only $10-40\%$ of the mass supplied to the accretion flow, while the rest is expelled in winds. This accretion fraction decreases with mass supply rate and is lower for high-spin systems. Both spin states produce strong MAGNETically driven outflows. For $a = 0$, the wind kinetic, radiative, and electroMAGNETic efficiencies are modest and show little variation across the full simulated range of accretion rates. For $a = 0.9$, both wind power and JET power increase super-linearly with $\dot{M}_{\rm acc}$, with the JET power saturating beyond $\dot{M}_{\rm acc} \sim 100\,\dot{M}_{\rm Edd}$. Radiation is strongly beamed along the funnel, with inverse beaming factors exceeding $100$ for high-spin, high-$\dot{m}$ models viewed face-on. Our results establish that rapid BH spin boosts energy-extraction efficiency, while high accretion rate amplifies total power. We provide scaling relations for luminosities, JET power, accretion ratio, and beaming, offering a framework for interpreting observations of ULXs and other super-Eddington systems.
[abstract 3 / 13] Yes (score: 5) - Title: Extending the Comisso-Asenjo Energy Extraction Mechanism to Pure Lovelock GravityAuthors: Chen Zhou, Ikhtiyor Eshtursunov, Sanjar Shaymatov, Chengxun Yuan,Comments: 13 pages, 7 captioned figuresSubjects: gr-qcCreated: 2026-07-30; Updated: 2026-08-03; Datestamp: 2026-08-03
In this paper, we extend the Comisso-Asenjo MAGNETic RECONNECTion (MR) mechanism to rotating BLACK HOLEs (BHs) in pure Lovelock/Gauss-Bonnet (GB) gravity in dimension $2N+2\leq D\leq 4N+1$ (where $N$ is the Lovelock polynomial degree of $N$th order term in the action). We perform a comprehensive analysis of the efficiency and power of extracted energy by exploring the effects of the spin parameter, plasma MAGNETization, MAGNETic field orientation, and RECONNECTion location. Our results reveal distinctive energetic features of pure Lovelock BHs relative to their Einstein counterparts, except in the special case of $D=3N+1$, where the two theories coincide. Our results demonstrate that MAGNETic RECONNECTion becomes increasingly efficient in extracting rotational energy from rapidly rotating pure Lovelock BHs with single rotation configuration as the spacetime dimension increases from $D=6$ to $9$. Furthermore, the Comisso-Asenjo MR mechanism can produce higher extraction power than the Blandford-Znajek (BZ) process in certain regions of parameter space because of its enhanced energy extraction rate. These results show that MAGNETic RECONNECTion is an efficient mechanism for extracting rotational energy from rapidly rotating pure Lovelock/GB BHs, highlighting their relevance to high-energy astrophysical phenomena.
[abstract 4 / 13] Yes (score: 4) - Title: Deep Learning-Based Classification and Analysis of Pulsar Candidates in FERMI-LAT Unassociated SourcesAuthors: C. Pozo González, R. López-Coto, J. Méndez-Gallego, E. de Oña Wilhelm,Comments: Accepted in Astronomy & Astrophysics (A&A)Subjects: astro-ph.HECreated: 2026-07-30; Updated: 2026-08-03; Datestamp: 2026-08-03
The Large Area Telescope (LAT) has revolutionized our understanding of the high-energy sky, yet approximately one-third of the sources in the Fourth FERMI-LAT Source Catalog (4FGL) remain unassociated. Conventional machine learning, such as Decision Trees, often treat spectral features as independent tabular entries, neglecting the sequential topological information inherent in the Spectral Energy Distribution (SED). We aim to classify unassociated FERMI-LAT sources by exploiting the intrinsic shape of their spectra and variability features, avoiding the use of galactic coordinates as training features. Our primary objective is to generate a high-confidence list of PSRs candidates, further distinguishing between Young Pulsars (YPs) and Millisecond Pulsars (MSPs). We developed a hierarchical deep learning framework based on a 1D Convolutional Neural Network (1D-CNN), named TabularResCNN. This architecture treats the spectral data from the 4FGL catalog, allowing the model spectral shape. The classification is performed in two stages: first discriminating between AGNs and PSRs, and subsequently categorizing PSRs into YPs and MSPs. We implemented a cost-sensitive learning strategy to handle class imbalance and utilized Grad-CAM techniques to ensure the physical interpretability of the model's decisions. Applying this framework to 2563 unassociated sources, we identified 1136 AGNs and 202 high-confidence PSR candidates (166 YPs, 36 MSPs), increasing the pulsar population by more than 60%. They exhibit strong astrophysical consistency: YPs are confined to the Galactic plane, MSPs show a broader vertical distribution, and AGNs are isotropic. Furthermore, we identified 5 out of 5 PSRs recently confirmed by FAST. The proposed 1D-CNN framework isolates PSRs candidates based on intrinsic spectral and temporal properties, minimizing spatial bias.
[abstract 5 / 13] Yes (score: 4) - Title: Energy-dependent Optical/Near-infrared and X-ray Correlations in SWIFT J1727.8-1613Authors: Ruican Ma, Federico Vincentelli, Diego Altamirano, Alexandra Veledina, Poshak Gandhi, Piergiorgio Casella, Tariq Shahbaz, Sian Woahene-Demehin,Comments: 9 pages, 9 figures. Accepted for publication in MNRASSubjects: astro-ph.HE hep-phCreated: 2026-07-30; Updated: 2026-08-03; Datestamp: 2026-08-03
We present a timing analysis of the BLACK HOLE transient SWIFT J1727.8-1613 during its intermediate state. We use coordinated broadband X-ray observations from Insight-HXMT (2-150 keV), together with optical data from ULTRACAM (g_s and i_s bands) and near-infrared data from HAWK-I (K_s band), obtained on 2023 September 9. As shown by previous studies, the Fourier power spectrum shows a strong quasi-periodic oscillation (QPO) in the K_s, i_s and X-ray bands. Cross-correlation analysis reveals a complex coupling between the optical/near-infrared (OIR) and X-ray emission, including a delayed optical anti-correlation, a strong infrared correlation, and a pronounced dependence of these features on X-ray energy, suggesting multiple Comptonisation regions. In contrast, the lag properties do not change at the QPO frequency, displaying an OIR lag of ~60-80 ms up to 150 keV. We discuss these results in the context of small-scale JET and hot accretion flow scenarios.
[abstract 6 / 13] (score: 3) - Title: Quiescent Host Galaxies of Extended Quasars Revealed by Spectrophotometric DecompositionAuthors: Shengxiu Sun, Linhua Jiang, Zhiwei Pan, Małgorzata Siudek, Mar Mezcua, Gaocheng Yin, Swayamtrupta Panda, Wei-Jian Guo, Steven Ahlen, David Brooks, Todd Claybaugh, Axel de la Macorra, Peter Doel, Enrique Gaztañaga, Gaston Gutierrez, Theodore Kisner, Andrew Lambert, Martin Landriau, Aaron Meisner, Ramon Miquel, John Moustakas, Ignasi Pérez-Ráfols, Eusebio Sanchez, David Schlegel, Michael Schubnell, Hee-Jong Seo, David Sprayberry, Gregory Tarlé, Benjamin Alan Weaver, Rongpu Zhou,Comments: Published in The Astrophysical Journal, 1004, 13 (2026), 20 pages, 20 figuresSubjects: astro-ph.GA astro-ph.IMCreated: 2026-07-30; Updated: 2026-08-03; Datestamp: 2026-08-03
Previous works of low-redshift QUASAR host galaxies have focused on compact QUASARs and found that their host galaxies are mainly star-forming galaxies. Here we present a study of host galaxies for QUASARs with extended morphologies in ground-based optical images. We select a sample of more than 1000 type 1 QUASARs at redshift $0.1
[abstract 7 / 13] (score: 3) - Title: Changing-Look AGNs from DESI. VI. Host GalaxiesAuthors: Shengxiu Sun, Linhua Jiang, Wei-Jian Guo, Sarah E. I. Bosman, Zhiwei Pan,Comments: Submitted to The Astrophysical Journal; 20 pages, 12 figuresSubjects: astro-ph.GA physics.data-anCreated: 2026-07-30; Updated: 2026-08-03; Datestamp: 2026-08-03
Changing-look (CL) AGNs trace rapid changes in nuclear activity, but their connection to host galaxy properties remains unclear. We present a study of the host galaxies of 105 CL AGNs previously selected by comparing DESI and SDSS data. We apply a two-epoch spectrophotometric decomposition to the DESI and SDSS spectra of the 105 objects. Meanwhile, HSC images are used to constrain their varying AGN components and non-varying stellar population components. We find that 79 of the 105 (75.2%) CL AGN hosts are quiescent galaxies, and 31/105 (29.5%) also show post-starburst signatures. We focus on 82 CL AGNs with extended host emission in the HSC images and compare them with extended QUASARs at similar redshift and stellar mass. Their STAR FORMATION activity, Balmer absorption, and quiescent fractions are broadly consistent with those of the comparison QUASARs, although post-starburst hosts are more common among the CL AGNs. Our CL AGNs with extended host emission are more often quiescent than those with compact morphology, but this difference is not apparent after matching in redshift and stellar mass. The $\mathrm{O\, \small II}$ and $\mathrm{O\, \small III}$ narrow lines show no population-wide response to the continuum and broad line changes, consistent with the slower response expected from the narrow line region. Together, these results favor changes in the central supermassive BLACK HOLE accretion rate as the main origin of the CL transitions.
[abstract 8 / 13] (score: 2) - Title: Faraday Complexity and Depolarisation in a High-Rotation-Measure Radio Galaxy from the Spectra and Polarisation In Cutouts of Extragalactic Sources (SPICE-RACS) DR2Authors: Debajyoti Mondal, Abhik Ghosh, Dipanjan Banerjee,Comments: 16 pages, 7 figures, 4 tables. Accepted for publication in The Astrophysical Journal (ApJ)Subjects: astro-ph.COCreated: 2026-07-31; Updated: 2026-08-03; Datestamp: 2026-08-03
We present a broadband spectro-polarimetric analysis of the extragalactic radio source \texttt{RACS\_0900-28\_7036} using SPICE-RACS DR2 observations with the Australian Square Kilometre Array Pathfinder (ASKAP). The source was selected for its large rotation measure (${\rm RM}=345.7\pm0.2~{\rm rad~m^{-2}}$), substantial excess relative to the local foreground ($Δ{\rm RM}\approx171~{\rm rad~m^{-2}}$), and strong evidence of Faraday complexity ($σ_{\rm add}/δσ_{\rm add}\approx8.6$). Observations span 803--1083~MHz in 36 spectral channels, enabling detailed characterization of Faraday rotation and wavelength-dependent dePOLARIZATION. One-dimensional QU-fitting and Bayesian model selection identify a multi-component model comprising one Burn-slab component and two external Faraday dispersion components (1 Slab + 2 EFD) as the preferred description. The dominant astrophysical component exhibits ${\rm RM}\approx345.5~{\rm rad~m^{-2}}$ with modest Faraday dispersion ($σ_{\rm RM}\approx3~{\rm rad~m^{-2}}$), consistent with the Galactic foreground rotation measure at the source position (${\rm RM}_{\rm Gal}=331.9\pm33.1~{\rm rad~m^{-2}}$). A secondary broader component at ${\rm RM}\approx131.5~{\rm rad~m^{-2}}$ shows strong dePOLARIZATION ($σ_{\rm RM}\approx19.5~{\rm rad~m^{-2}}$), indicating an additional turbulent Faraday-active medium along the line of sight. The fractional POLARIZATION spectrum and $q$--$u$ plane evolution further confirm multiple Faraday-active regions along the line of sight. These results demonstrate that ASKAP broadband spectropolarimetry can resolve complex Faraday structures and probe turbulent MAGNETized environments, providing a framework for systematic dePOLARIZATION studies across the full SPICE-RACS catalog and enabling statistical investigations of Faraday complexity in diverse extragalactic radio sources.
[abstract 9 / 13] (score: 2) - Title: Post-Newtonian N-Body Dynamics in Extended Theories of GravityAuthors: Antonio Tedesco,Comments: 19 pages; published in The European Physical Journal C, 86, 885 (2026). This replacement corrects only misprints and the ORCID link to reflect the published article; it does not constitute a revised scientific version. v1 is the manuscript accepted by EPJ C and submitted to arXiv on July 12, 2026; v2 only fixed the automatic LaTeX title-page dateSubjects: gr-qcCreated: 2026-07-30; Updated: 2026-08-03; Datestamp: 2026-08-03
We derive the complete first post-Newtonian (1PN) Lagrangian and corresponding equations of motion for the RELATIVISTIC $N$-body system in Scalar-Tensor-Fourth-Order Gravity (STFOG), including the Non-Commutative Spectral Geometry (NCSG) sector as a special case. In the regime $Φ\sim Ψ$ ($γ\sim 1$), the linearized fourth-order field equations are solved in the Standard Post-Newtonian gauge, and the variational Lagrangian is built directly from the point-particle action. The resulting dynamics is governed by three Yukawa functions $ζ$, $\mathcal{W}$ and $Ξ$, which encode the scalar, gravitoMAGNETic and three-body sectors and depend on the effective masses $(m_R,m_Y,m_ϕ)$ of the additional propagating modes. In this context, we show that the nonlinear metric component ${}^{(4)}\!g_{00}$ plays no role at 1PN level. The 1PN orbital motion of the above extended theories is thus obtained in closed form, and the Einstein--Infeld--Hoffmann equations are recovered in the corresponding general-RELATIVISTIC limit. The formalism provides a common framework for RELATIVISTIC celestial mechanics and applies to Solar System, binary pulsars such as PSR J0737-3039, Galactic-center stellar orbits and triple systems.
[abstract 10 / 13] (score: 2) - Title: Impact of eccentricity and higher-modes on neutron star-BLACK HOLE parameter estimationAuthors: Snehal Tibrewal, Aasim Jan, Aaron Zimmerman, Hsin-Yu Chen,Comments:Subjects: astro-ph.HECreated: 2026-07-31; Updated: 2026-08-03; Datestamp: 2026-08-03
Detections of gravitational waves from neutron star-BLACK HOLE systems provide avenues for studying extreme matter, constraining binary formation channels, and testing the nature of compact objects in strong gravity. Eccentric signatures in the signal further enhance this potential by improving parameter estimation and offering clues about binary formation. Because eccentricity is primarily imprinted during the inspiral phase, it is often weakly constrained or missed entirely in binary BLACK HOLE observations; in contrast, neutron star-BLACK HOLE systems produce longer in-band signals, enabling more precise measurements of eccentricity and leaving a distinct imprint on parameter inference. In this work, we present a systematic parameter-estimation study exploring the impact of eccentricity on inference using injections simulated with the state-of-the-art eccentric waveform model SEOBNRv5EHM. We find that for systems like GW200105_162426, the measurement precision of eccentricity and correlated parameters improves as eccentricity increases, yielding tighter constraints at larger eccentricities. For the highest eccentricity considered in this study, $e=0.25$, we recover eccentricity with $1σ$ uncertainty as low as $4\times10^{-4}$. In addition, the constraints on effective spin $χ_\mathrm{eff}$ and mass ratio $q$ improve relative to the quasi-circular case by factors of $\sim13$ and $\sim20$, respectively. On the other hand, we find no significant improvement in extrinsic parameters such as luminosity distance and sky localization, suggesting that for systems like GW200105_162426, the additional information provided by eccentricity in this sector is either negligible or degenerate with the information provided by higher-order modes.
[abstract 11 / 13] (score: 2) - Title: Light propagation and intensity transport in metric-affine geometryAuthors: Antonio De Felice, Lavinia Heisenberg, Gonzalo J. Olmo, Carlos Pastor-Marcos,Comments: 10 pagesSubjects: gr-qcCreated: 2026-07-28; Updated: 2026-08-03; Datestamp: 2026-08-03
We study electroMAGNETic wave propagation in metric--affine geometries, where torsion and non-metricity may be present and the coupling between electroMAGNETism and spacetime is no longer unique. Rather than choosing a particular coupling prescription a priori, we construct electroMAGNETic sectors that preserve standard $U(1)$ gauge invariance and projective invariance of the affine connection as guiding symmetry principles. We introduce two representative models, one in which the Maxwell term is dressed by a scalar prefactor built from non-Riemannian invariants, and another in which the kinetic term is modified by a rank--four constitutive tensor acting as an anisotropic medium. We derive their geometric--optics limits and show that their couplings can modify the effective light cone, change the relation between field amplitude and intensity, induce POLARIZATION-dependent propagation, and generate birefringence and mode mixing. These results thus provide the formal basis for a broader phenomenological study connecting torsion and non-metricity with electroMAGNETic observables in concrete metric--affine backgrounds, including black-hole imaging, birefringent lensing, POLARIZATION observables, and departures from photon-number conservation.
[abstract 12 / 13] (score: 2) - Title: Understanding constraints on primordial mass BLACK HOLEs made of DARK MATTER using fast radio burstsAuthors: Surajit Kalita, Shruti Bhatporia, Amanda Weltman,Comments: 3 pages with 1 figure; based on poster in IAU XXXII General Assembly, August 2024, Cape TownSubjects: astro-ph.CO astro-ph.HE gr-qcCreated: 2026-07-30; Updated: 2026-08-03; Datestamp: 2026-08-03
In recent decades, a multitude of modified gravity theories have been proposed to address a variety of cosmological and astrophysical problems. While many of these theories remain viable, observational constraints on their parameters are increasingly stringent. Fast Radio Bursts (FRBs), in particular, have emerged as powerful probes of cosmology and fundamental physics. This study investigates the implications of a generic modified gravity theory for gravitational lensing by FRBs. By analyzing the dataset of CHIME/FRBs, we constrain the fraction of DARK MATTER composed of primordial BLACK HOLEs within this theoretical framework. Furthermore, we demonstrate that modified gravity introduces a screening effect on gravitational lensing, analogous to the scattering effect of plasma on light rays.
[abstract 13 / 13] (score: 2) - Title: Misaligned or chaotic? A strong break of axial symmetry in the local LRD J1025 revealed with VLT/FORS2 spectropolarimetryAuthors: Francesco D'Eugenio, Gabriele Pezzulli, Roberto Maiolino, Alessandro Marconi, Xihan Ji, Cristina Ramos Almeida, Andrea Ferrara, Piero Madau, Xiaojing Lin, José A. Acosta-Pulido, Fuyan Bian, Matilde Brazzini, Zheng Cai, Stefano Carniani, Xiaohui Fan, Ignas Juodžbalis, Robert G. Pascalau, Jan Scholtz, Charlotte Simmonds, Fengwu Sun, Sandro Tacchella,Comments: 21 pages, 12 figures. Submitted to MNRAS, comments welcomeSubjects: astro-ph.GACreated: 2026-07-30; Updated: 2026-08-03; Datestamp: 2026-08-03
Little Red Dots (LRDs) are compact ACTIVE GALACTIC NUCLEi (AGN) with unusual spectral energy distributions and broad Balmer emission, candidate signposts of rapid black-hole growth. We present VLT/FORS2 optical linear spectropolarimetry of the closest known LRD, SDSS J102530.29+140207.3, at z=0.1. In total light, we detect spatially extended narrow-H$α$ emission, probably tracing the host galaxy. We measure a nearly grey continuum polarisation $p_{\rm cont}=1.53\pm0.04$(rand.)$\pm$0.20(syst.) per cent, while broad H$α$ is less polarised, $p_{\rm Hα}=0.58-0.84$ per cent. We rule out polarisation by Milky Way dust and dilution by an unpolarised line. The polarised continuum with a depolarised line resembles local Seyfert-1 nuclei and favours a single dominant source over multi-source explanations. After Stokes-continuum subtraction, broad H$α$ shows no blue-to-red swing, but there is a significant (48$\pm$4)$^\circ$ continuum-to-line offset in polarisation angle. This implies a break of axial symmetry inside this object, posing interesting geometrical challenges to all existing LRD models and frameworks. We discuss different possible origins of this symmetry break and possible paths to discriminate between them with future observations.
arXiv:2607.28714 [pdf, ps, other]
arXiv:2607.28919 [pdf, ps, other]
arXiv:2607.28789 [pdf, ps, other]
arXiv:2607.28723 [pdf, ps, other]
arXiv:2607.28852 [pdf, ps, other]
arXiv:2607.28732 [pdf, ps, other]
arXiv:2607.28735 [pdf, ps, other]
arXiv:2606.07919 [pdf, ps, other]
arXiv:2607.10889 [pdf, ps, other]
arXiv:2607.16135 [pdf, ps, other]
arXiv:2607.26141 [pdf, ps, other]
arXiv:2607.28704 [pdf, ps, other]
arXiv:2607.28715 [pdf, ps, other]