A matrix free action of the Ashtekar-Lewandowski volume operator of loop quantum gravityThe Ashtekar-Lewandowski (AL) volume operator of loop quantum gravity is central to the Hamiltonian constraint, but its vertex action is usually obtained from dense spectral decompositions of finite…Waleed Sherif·Jun 30, 2026SaveLearn
Limits of the Rastall--Einstein Equivalence: Matter-Action Compatibility, FLRW Dynamics, and Exceptional SectorsA regular Rastall metric equation can be written exactly as an Einstein equation with a conserved algebraic source. We examine whether this source redefinition also preserves a specified local…José A. C. Nogales, Karen-Luz Burgoa Rosso, Marcelo H. Alvarenga·Jun 30, 2026SaveLearn
Spontaneous spherical symmetry breaking of black holes with resonant hairBlack holes with resonant hair are static, spherical, electrically charged solutions of the Einstein-Maxwell-(gauged-)scalar system. Scalar self-interactions are mandatory for their existence.…José Ferreira, Carlos A. R. Herdeiro, Eugen Radu et al.·Jun 30, 2026SaveLearn
Photon Propagation and Black Hole Imaging in Kruglov Nonlinear ElectrodynamicsWe investigate the effective photon geometry associated with black holes in Kruglov nonlinear electrodynamics and its consequences for strong-field optical phenomena. This model constitutes a…H. S. Ramadhan, M. F. Fauzi, D. A. Witjaksana et al.·Jun 30, 2026SaveLearn
A short course in general relativityThese notes give a concise introduction to General Relativity at the advanced undergraduate level, starting from the weak field limit and gravitational waves, then introducing curved manifolds and…James M. Cline·Jun 30, 2026SaveLearn
Power law scalar potential in the Saez-Ballester like theory: Exact solutions in the Bianchi type I caseWe investigate exact anisotropic Bianchi type I cosmological solutions in a generalized S'aez--Ballester--K-essence-like theory containing two interacting scalar fields with quintessence,…J. Socorro, A. Gil-Ocaranza, Juan Luis Pérez·Jun 30, 2026SaveLearn
Parametrizing superfluid dark matter with rational approximationsWe investigate how a spatially modulated real scalar background ϕ(x) can modify phonon propagation in the context of Superfluid dark matter (SFDM). Using a simple toy model with quartic…Francesco Lottatori·Jun 30, 2026SaveLearn
Detecting the Unruh Effect via an Engineered Low-Mass Field in a Superconducting QubitDetecting the Unruh effect is a major challenge in fundamental physics. It is known that exciting massive fields with the Unruh thermal bath is heavily suppressed when the field's rest energy is…Vladimir Toussaint·Jun 30, 2026SaveLearn
Enhancement and Suppression of Decay Rates in an Accelerated Fermionic Cavity Coupled to a Massive FieldWe study a (1+1)-dimensional model in which a massless Dirac field, initially in an excited state inside a uniformly accelerated cavity, decays to its ground state, accompanied by the excitation of…Vladimir Toussaint·Jun 30, 2026SaveLearn
GW230814: investigation of a loud gravitational-wave signal observed with a single detectorGW230814, detected by the LIGO Livingston observatory with a signal-to-noise ratio of 42.4, represents the loudest gravitational-wave signal in the GWTC-4.0 catalog. Its source is consistent with a…The LIGO Scientific Collaboration, The Virgo Collaboration, The Kagra Collaboration et al.·Jun 30, 2026SaveLearn
Gravitational Wave Backreaction in f(R,G) GravityWe develop a complete framework for gravitational wave propagation and backreaction in f(R,G) modified gravity. Using a scalar-tensor formulation with two auxiliary fields, we derive the effective…Farzad Milani·Jun 30, 2026SaveLearn
Repetitive Penrose process for charged particles in Kerr-Newman black holesWe investigate the repetitive Penrose process for charged particles in an initially extremal Kerr--Newman black hole and develop a nonlinear iterative framework in which the black-hole mass, angular…Mohammad Reza Alipour, Saeed Noori Gashti, Mohammad Ali S. Afshar·Jun 29, 2026SaveLearn
Scalarization and descalarization in hyperbolic encounters of black holesWe use numerical relativity to study the scalar field evolution sourced by hyperbolic encounters of black holes in quadratic scalar Gauss-Bonnet gravity. In this theory, single black holes are known…Frederick C. L. Pardoe, Helvi Witek·Jun 29, 2026SaveLearn
Black holes in a bouncing universeBouncing cosmologies offer an alternative to the standard ΛCDM model by avoiding the problem of the initial cosmological singularity by construction. In these models, the universe undergoes a…Iara Pintos, Daniela Pérez, Florencia L. Vieyro·Jun 29, 2026SaveLearn
Dynamical Completion of Coupling-Charge ThermodynamicsThe scalar-gauge pair formulation promotes gravitational coupling constants to conserved charges, clarifying their role in extended black hole thermodynamics. However, its original incarnation…Kamal Hajian, Bayram Tekin·Jun 29, 2026SaveLearn
Efficient Eccentric Effective-One-Body Dynamics via Near-Identity Averaging TransformationsNext-generation gravitational-wave detectors, such as LISA, the Einstein Telescope, and Cosmic Explorer, will require accurate and efficient models of long-lived black-hole binary signals, including…Philip Lynch, Alessandra Buonanno, Aldo Gamboa et al.·Jun 29, 2026SaveLearn
Evaluating the Fourier Approximation in Pulsar Timing Array AnalysisPulsar timing arrays search for stochastic processes such as gravitational waves by comparing pulse time of arrival data for millisecond pulsars to expectations from a background with a given power…Yongqi Zhang, Hayden Scholz, Ken D. Olum et al.·Jun 29, 2026SaveLearn
Comment on the "New Rotating Black Hole in Electromagnetic Fields: Cosmological Horizon without Cosmological Constant''In this comment we discuss some properties of the novel spacetime, recently found in [L. Ma, H. Lü, arXiv:2606.23782]. In particular, we draw attention to the background of this solution that the…Hryhorii Ovcharenko·Jun 29, 2026SaveLearn
Orbital, Shadow, and Thin-Disk Signatures of a Regular Black Hole with Gravitational Self-EnergyWe investigate geodesic motion, shadow observables and thin-disk accretion for the regular black hole generated by a non-local gravitational self-energy contribution. The geometry is controlled by a…Erdinç Ulaş Saka·Jun 29, 2026SaveLearn
Wave Optics Effects from Gravitational Wave Propagation Through Dark Matter HalosGravitational wave (GW) propagation is usually studied under the geometric optics approximation. But when GWs propagate through structures of sizes similar to their wavelength, this approximation…Annamalai P. Shanmugaraj, Roland Haas, Erik Schnetter et al.·Jun 29, 2026SaveLearn
Black holes with regular scalar hair in Brans-Dicke gravity via the Herglotz variational principleBrans-Dicke theory is reformulated within the Herglotz variational principle (HVP), and an exact black hole solution with scalar hair is obtained for ω0=0 and vanishing potential V(ϕ)=0. The…Marek Wazny·Jun 29, 2026SaveLearn
Photon Motion and Shadows of Rotating Black Holes with Nonlinear Electromagnetic and Anisotropic Matter FieldsThis paper investigates the effects of the nonlinear electromagnetic field and the anisotropic matter field on photon motion, shadow structures, and the energy emission rate of a rotating black hole…Mou Xu, Jianbo Lu, Yu Liu et al.·Jun 29, 2026SaveLearn
Mass-Varying Dark Matter Induced Scalarization and Scalar Clouds around Black HolesWe consider a black hole solution embedded in a mass varying dark matter (DM) halo and study scalarization induced by DM. We derive the required conditions on the scalar DM coupling that allow for a…H. Mohseni Sadjadi, M. Navid Gasemi Zad·Jun 29, 2026SaveLearn
Gravitational time advancement effect in Bumblebee gravity for Earth bound systemsThis paper is a novel application of the new effect of gravitational time advancement or negative time delay, first predicted for static black holes (spin a=0), that can be regarded as…G. Y. Tuleganova, R. Kh. Karimov, R. N. Izmailov et al.·Jun 29, 2026SaveLearn
On a Class of Harko-Kovacs-Lobo WormholesThe Harko, Kovács, and Lobo wormhole (HKLWH) metric contains two free parameters: one is the wormhole throat r0, and the other is a dimensionless deviation parameter γ with values 0<γ<1, the…R. Kh. Karimov, R. N. Izmailov, K. K. Nandi·Jun 29, 2026SaveLearn