Geodesic Focusing Conditions in f(Q) GravityWe study the geodesic deviation equation in symmetric teleparallel geometry (STG), where the relative acceleration is defined with respect to the STG connection. We analyze the modified Raychaudhuri…Chao-Qiang Geng, Chunhui Liu, Ling-Wei Luo et al.·Aug 4, 2026SaveLearn
Primordial Black Holes: A Review of Formation and EvolutionPrimordial Black Holes (PBHs) have emerged as a leading non-particulate candidate for dark matter and a unique cosmological probe, a paradigm shift accelerated by the detection of anomalous binary…S. Shankaranarayanan, Soumya Bhattacharya, Archit Vidyarthi·Aug 4, 2026SaveLearn
Black-Hole Echo Resonance Spectra and Source Dependence in a Controlled Transfer-Function ModelEcho models phenomenologically encode possible near-horizon structure by replacing the purely ingoing horizon-side condition with an effective reflecting inner boundary near the would-be horizon. We…Masahiro Kaminaga·Aug 4, 2026SaveLearn
The Szekeres metrics with M < 0The evolution equation of the Szekeres metrics allows solutions with the mass function M < 0. They exist in both classes of the Szekeres metrics, have no Big Bang singularity and no origin. In both…Andrzej Krasiński·Aug 4, 2026SaveLearn
Traversable Wormholes induced by polytropic n=1 energy densityWe investigate spherically symmetric and static traversable wormholes supported by exotic matter, focusing on solutions sourced by physically motivated dark matter energy density profiles.…Remo Garattini, Francisco S. N. Lobo, Kirill Zatrimaylov·Aug 4, 2026SaveLearn
Quantum Big Bounce in Wheeler-DeWitt scattering theory: Ekpyrotic and LQC-like transitionsWe present a rigorous description of the quantum dynamics of the closed isotropic Universe in the presence of an ekpyrotic-like scalar field, expressed in terms of relativistic quantum scatterings.…S. Lo Franco, G. Montani·Aug 4, 2026SaveLearn
Role of the Dynamic Degree of Freedom in Scalar-Tensor Non-Metricity Gravity with Curved FLRW GeometryWe investigate a non-minimally coupled scalar field theory within the framework of scalar-tensor non-metricity gravity, focusing on spatially curved FLRW spacetimes. Employing the dynamical systems…Ghulam Murtaza, Avik De, Andronikos Paliathanasis·Aug 4, 2026SaveLearn
Relativistic formulation for dual one-way Doppler Cancellation Scheme observables for gravitational redshift testsGravitational redshift is a fundamental prediction of general relativity and a sensitive probe of possible deviations from it. Motivated by recent progress in optical clocks and satellite-ground…Cheng-Gang Qin, Tong Liu, Yang Li et al.·Aug 4, 2026SaveLearn
Detecting Lorentz-violation induced by a tensor field with S-star's motion around Sgr A*Testing Lorentz symmetry in strong gravitational fields provides a unique probe of extensions to standard model. The orbiting motions of the S-stars around the supermassive black hole Sgr~A* provide…Qi Qi, Yu Sang, Xiao-Mei Kuang·Aug 3, 2026SaveLearn
A fast, differentiable neural-network surrogate for precessing binary black-hole waveformsGravitational-wave parameter estimation requires millions of waveform evaluations per event, a cost that constrains real-time inference and population studies. We present a fast, fully differentiable…Beka Modrekiladze·Aug 3, 2026SaveLearn
Density-preserving core-Einasto black holes with Event Horizon Telescope boundsA Newtonian halo density does not uniquely determine a relativistic spacetime, and the resulting completion ambiguity can dominate predicted horizon-scale signals. We make this dependence explicit…Ali Övgün, Reggie C. Pantig·Aug 3, 2026SaveLearn
Horizon-Brightened Acceleration Radiation and the Deflection Angle Near a Degenerate Photon Sphere of Schwarzschild-like Quantum-Corrected Black HoleWe investigate horizon-brightened acceleration radiation (HBAR) and a strong-deflection expansion for the deflection angle of light rays scattered in the vicinity of a degenerate photon sphere,…Yunqiao Xu, Uktamjon Uktamov, Bobomurat Ahmedov et al.·Aug 3, 2026SaveLearn
Observational Signatures of Static and Rotating Wormholes Embedded in Dark MatterWe study static and slowly rotating traversable wormholes embedded in two contrasting dark matter environments, the cuspy Navarro-Frenk-White (NFW) halo and the cored solitonic wave dark matter…Zinnat Hassan, Paras Balani, P. K. Sahoo·Aug 3, 2026SaveLearn
Bessel-Hagen currents for linearised Weyl-squared gravityFor the Fierz-Pauli action the Bessel-Hagen construction does not produce a preferred local gauge-invariant energy-momentum tensor; it identifies only a gauge-invariant equivalence class of Noether…Michael Hobson, Will Barker, Anthony Lasenby·Aug 3, 2026SaveLearn
Formation of extremal regular black holesStatic and slowly evolving regular black holes with a non-extremal inner horizon are generally expected to suffer from mass inflation. Here we consider the scenario of asymptotic gravitational…Johanna Borissova·Aug 3, 2026SaveLearn
Regular fluid of strings black hole with non trivial core and asymptotic structure by gravitational decouplingCloud-of-strings (CS) geometries provide an effective description of one-dimensional string distributions. However, their central singularity cannot be removed through the standard regular black…Milko Estrada, Luis C. N. Santos, Leonardo G. Barbosa·Aug 3, 2026SaveLearn
Integral Hilbert spaces and the dynamics of loop quantum cosmosPolymer quantization program applied in Loop Quantum Gravity/Cosmology leads to nonseparable Hilbert spaces. Commonly, one sidesteps this problem by singling out and working with a separable…Janek Kozicki, Tomasz Pawłowski·Aug 3, 2026SaveLearn
Black bounces to traversable wormholes from pure gravity in four and higher dimensionsThis article derives static and spherically symmetric wormhole and black bounce spacetimes as vacuum solutions of metric gravitational theories in four and higher dimensions. To this end, I extend…Jacopo Mazza·Aug 3, 2026SaveLearn
Dark Matter Signatures in Black Hole Thermodynamics and Information RecoveryIn this paper, we investigate the thermodynamic properties and information recovery of Schwarzschild and Reissner--Nordstr"om black holes surrounded by perfect fluid dark matter. We show that,…Yahya Ladghami, Brahim Asfour, Taoufik Ouali·Aug 3, 2026SaveLearn
On Modeling Anisotropic Quark Stars: The Role of Anisotropy in Radial Oscillation SpectraWe model the compact object Cen X-3, which is considered to be a good strange quark star candidate of known mass and radius, incorporating a negative anisotropic factor, and we compute the…G. Panotopoulos·Aug 3, 2026SaveLearn
Determination of the Angular Momentum of Radiated Gravitons, Scalars, and Dark Photons from Binary OrbitsWe compute the energy and angular momentum radiated by compact binaries through gravitational waves, scalar and vector fields, using the field-theoretic approach. We observe that each emitted…Arpan Hait, Subhendra Mohanty·Aug 3, 2026SaveLearn
Novel Observable Signals from First-Order Gravitational Phase TransitionsSpontaneous scalarization is a well-known phenomenon in scalar-tensor theories, featuring large deviations from general relativity. However, some of its signatures are hard to detect, because it is…Murat Özinan, Oğuzhan K. Yamak, Fethi M. Ramazanoğlu·Aug 3, 2026SaveLearn
A parity selection rule for regular black holesRegular black hole metrics are usually studied kinematically, but a finite-curvature static core does not guarantee that the underlying theory can consistently evolve generic matter through a regular…Farid Thaalba, Julio Arrechea, Stefano Liberati·Aug 3, 2026SaveLearn
Hidden Symmetry of Kerr-deSitter from Manifest Symmetry of Painlevé VIWe show that the recently discovered ``mass symmetries" of the radial Teukolsky equation for Kerr-deSitter black holes can be understood from a corresponding symmetry of the Painlevé VI equation…Stefan Hollands, Akihiro Ishibashi, Jochen Zahn·Aug 3, 2026SaveLearn
Charged Black Holes with a Lorentz--Violating Kalb--Ramond BackgroundWe investigate exact static, spherically symmetric electrically charged black hole solutions in a gravitational theory with spontaneous Lorentz-symmetry breaking induced by a background Kalb--Ramond…Jia-Hui Yang, Xin-Yu Guo, Jia-Zhou Liu et al.·Aug 3, 2026SaveLearn