Electromagnetism from two matter spaces: mutual helicity and the nondegenerate completionWe show that generic Maxwell fields can be represented within the matter-space framework by introducing two independent matter-space flows. In the one-flow formulation the electromagnetic field…Hyeong-Chan Kim·Jun 14, 2026SaveLearn
Shadow of Rotating Black Hole Immersed in Dark Matter HaloThe recent black hole shadow observations by the Event Horizon Telescope provide a unique opportunity to probe both the strong gravity regime and the environment surrounding supermassive black holes.…Yong-You Liu, Tian-Yun Ye, Zhen Li·Jun 14, 2026SaveLearn
Running Vacuum in the expanding Universe: a unified QFT paradigm for Inflation and Dark EnergyThe concordance ΛCDM model, based on a rigid Λ-term for the entire cosmic history, has been in crisis for a long time. In our expanding Universe, an evolving Λ with the expansion is intuitively…Joan Solà Peracaula·Jun 14, 2026SaveLearn
Black Hole Entropy Beyond the Wald Term in Nonminimally Coupled Gravity: A Covariant Phase Space DecompositionWe study the entropy of static, spherically symmetric black holes in diffeomorphism-invariant theories with nonminimal matter--curvature couplings, using the covariant phase space formalism. For…Jia-Zhou Liu, Shan-Ping Wu, Shao-Wen Wei et al.·Jun 14, 2026SaveLearn
Towards a unified quantum field theory of dark energy and inflation: unstable de Sitter vacuum and running vacuumInflation is a necessary cosmic mechanism to cure basic inconsistencies of the standard model of cosmology. These problems are usually `fixed' by postulating the existence of a scalar field…Joan Solà Peracaula, Àlex González-Fuentes, Cristian Moreno-Pulido·Jun 14, 2026SaveLearn
Spin Curvatures in General Relativity and Two-Component Gravitons with Arbitrary SourcesWe present a short review of the spin curvatures that arise within the framework of one of the Infeld-van der Waerden formalisms for general relativity. All the spinor symmetries borne by the inner…Clésio E. Mota, Jorge G. Cardoso·Jun 14, 2026SaveLearn
Emergent gravity in superplastic crystalsWe discuss emergent gravity in the superplastic crystals. We restrict ourselves by the consideration of fermions coupled to gravity. Gravity itself is either Riemannian (without torsion) or…M. A. Zubkov·Jun 14, 2026SaveLearn
EMRI Dephasing from a Torsion-Inspired Near-Zone Kerr Deformation: Motivated by Spin-Polarized Dark MatterExtreme-mass-ratio inspirals (EMRIs) are sensitive probes of weak conservative perturbations in the strong-field region of massive black holes. We study a phenomenological EMRI model motivated by…Jingxu Wu, Liangyu Luo, Daniil Stepanenko et al.·Jun 13, 2026SaveLearn
Probing ΛCDM-mimicking f(Q) gravity model using gravitational waves from compact binary coalescencesThe direct detection of gravitational waves (GWs) is a very significant achievement in the history of physics and has opened a new window to probe the possible deviations of physics from that of…Sikha Gogoi, Umananda Dev Goswami·Jun 13, 2026SaveLearn
Cosmological Pseudo-EntropyWe study pseudo entropy S, a recent generalization of entanglement entropy, for scalar cosmological perturbations in de Sitter space with sound speed 0.024 ≤ cs ≤ 1, and in…Manghang Limbu, Pramod Kamal Kharel, Rohit Bhattarai et al.·Jun 13, 2026SaveLearn
General Relativity and Background IndependenceGeneral Relativity (GR) is widely regarded as a paradigmatic example of a background independent theory, a feature often taken to mark a decisive conceptual advance over its Newtonian and special…Antonio Vassallo·Jun 13, 2026SaveLearn
Eccentricity in Disguise? Insights from GW231123 and Numerically Simulated Binary Black Hole Merger SignalsGW231123 is a gravitational-wave signal originating from the merger of a black hole binary with total mass 250 M, the largest ever detected by the LIGO-Virgo-Kagra Collaboration.…Koustav Chandra, Johann Fernandes, Akshita Mittal et al.·Jun 13, 2026SaveLearn
On gravitational collapse and integrable singularitiesSchwarzschild black holes are expected to emerge as the end states of the classical gravitational collapse from non-singular configurations. After integrable curvature singularities appear, the…Roberto Casadio, Andrea Giusti, Alexander Kamenshchik et al.·Jun 13, 2026SaveLearn
Continuous Sensitivity Analysis for δN FormalismThe δN formalism provides a powerful non-perturbative framework for following the evolution of primordial curvature perturbations on super-horizon scales. However, its standard implementation…S. Mohammad Ahmadi·Jun 13, 2026SaveLearn
Black Hole--Entropy Container or CreatorDo black holes possess entropy or do they create it? The dominant assumption is that they possess entropy, and a they evaporate that entropy is emitted and decreases. In this paper I use a model of a…William G Unruh·Jun 13, 2026SaveLearn
Thermodynamically massless Simpson-Visser black holesIn this work we scrutinize the thermodynamic properties of the Simpson-Visser (SV) spacetime. Working within Einstein gravity coupled to nonlinear electrodynamics (NLED) and a scalar field with…Thanasis Karakasis, Emmanuel N. Saridakis, Zi-Yu Tang·Jun 13, 2026SaveLearn
Spin Induced Geometry: Emergence of Metric and Torsional Sectors from Spinor SourceWe present a geometric framework in which both metric and torsional degrees of freedom emerge dynamically from spinor currents, without being postulated as fundamental properties of the affine…Elisa Varani·Jun 13, 2026SaveLearn
Gauss-Bonnet Gravity and Spacetime SingularitiesWe investigate the effect of higher-order curvature terms, specifically Gauss-Bonnet terms, on spacetime singularities in five dimensions. For FLRW cosmologies, we demonstrate that Gauss-Bonnet terms…Tariq Allaithy, Adel Awad, Mohamed Hany Radwan et al.·Jun 13, 2026SaveLearn
Gravitational Foundations and Exact Solutions in n-Dimensional Fractional CosmologyThree theoretically plausible techniques to developing a fractional scalar field cosmological model are pointed in this paper; the time-dependent kernel weighted action being then selected. Upon this…S. M. M. Rasouli, J. Marto, D. A. V. Oliveira et al.·Jun 13, 2026SaveLearn
Searching Stochastic Gravitational Wave Background Landscape Across Frequency BandsGravitational wave (GW) astrophysics is entering a multi-band era with upcoming GW detectors, enabling detailed mapping of the stochastic GW background across vast frequencies. We highlight this…Yunjia Bao, Tore Boybeyi, Vuk Mandic et al.·Jun 13, 2026SaveLearn
Superradiance and Quasinormal Modes of Massive Scalar Fields around Kerr Black Holes in Einstein-Maxwell-Dilaton-Axion Theory with Perfect Fluid Dark MatterWe investigate the dynamics of massive scalar fields around Kerr black holes in the Einstein-Maxwell-dilaton-axion (EMDA) theory, incorporating the effects of perfect fluid dark matter (PFDM),…Teparksorn Pengpan·Jun 13, 2026SaveLearn
Short-range approximation to Casimir wormholes inspired by scalar and electric fieldsWe investigate a static traversable wormhole sustained by a combination of a minimally coupled scalar field and an electric field, with exotic matter sourced by Casimir energy. Considering two…Remo Garattini, Athanasios G. Tzikas·Jun 13, 2026SaveLearn
Non-minimal matter sector couplings in Lorentz-violating gravity: Self-consistent traversable wormholes and quasinormal modesThe anisotropies induced by Lorentz-violating fields pose significant challenges for the search for compact objects in non-vacuum environments. In this work, nevertheless, we demonstrate that…Renan B. Magalhães, Leandro A. Lessa, Rodolfo Casana·Jun 13, 2026SaveLearn
Gravitational lensing for interstellar power transmissionWe investigate the propagation of monochromatic electromagnetic waves through multiple, well-separated, monopole gravitational lenses in the thin-lens/eikonal approximation. For the axially aligned…Slava G. Turyshev·Jun 13, 2026SaveLearn
Perfect fluids revisited: an action principle approachWe revisit the variational principle for relativistic perfect fluids in a manifestly covariant formulation based on differential forms, with particular attention to the boundary data required for a…Kostas Tzanavaris·Jun 12, 2026SaveLearn