广义相对论与量子宇宙学

We investigate exact cosmological solutions with a massive scalar field minimally coupled to the Einstein-Hilbert action in General Relativity. For an extended Higgs-like scalar self-interaction, we find that the resulting field equations…

We systematically construct ghost-free scalar-tensor theories whose Lagrangian includes up to third-order derivatives of the scalar field. Using a spatially covariant action written in terms of the ADM variables, we impose degeneracy and…

We show that the consequences of a recent paper on quantum gravity are 1) a duality between point particles and massive scalar propagators, 2) the recovery of the entropy of a boundary (a black hole) in the same form as that of the EFT…

We investigate traversable wormhole solutions within the framework of $f(\mathscr{Q},\mathscr{L}_m)$ gravity, a symmetric teleparallel theory featuring non-minimal coupling between geometry and matter. Adopting a linear functional form…

The asymptotic safety program assumes that quantum gravity becomes renormalizable through ultraviolet fixed points in metric-based couplings. We demonstrate that this approach {encounters fundamental symmetry violations} across multiple…

We present the IMRPhenomXE frequency-domain phenomenological waveform model for the dominant mode of inspiral-merger-ringdown non-precessing binary black holes in elliptical orbits. IMRPhenomXE extends the quasi-circular IMRPhenomXAS…

Gravitational waves (GWs) can be distorted by intervening mass distributions while propagating, leading to frequency-dependent modulations that imprint a distinct signature on the observed waveforms. Bayesian inference for GW lensing with…

In this article, we extend our previously presented analytical formulas (Phys.Rev.D 109 (2024) 12, 124055) for describing light rays passing near or emitted in the vicinity of compact objects to a broader class of spherically symmetric,…

In this paper, we investigate the overlapping of photon rings - higher-order images of a black hole's luminous environment, concentrated near the shadow boundary and expected to be resolved in future observations. We consider a broad class…

The stochastic gravitational wave (GW) background is secondarily and inevitably induced by the primordial curvature perturbations beyond the first order of the cosmological perturbation theory. We analytically calculate the integration…

We constrain the parameter space of the Bumblebee model in a cosmological background and then investigate the properties of gravitational waves within the constrained parameter space. Our analysis reveals seven perturbative degrees of…

We developed a numerical code which evolves the semiclassical Einstein's equation (with the quantum stress-energy contribution added as a source term) for the spherically symmetric metric inside an evaporating semiclassical charged black…

In this paper we investigate how a regular scale-dependent black hole, characterized by a single extra parameter $\epsilon$, behaves under perturbations by a test field (quasi-normal modes) and under light imaging (shadows) in a…

Gravitational-wave astronomy has entered a regime where it can extract information about the population properties of the observed binary black holes. The steep increase in the number of detections will offer deeper insights, but it will…

We present a reanalysis of 17 gravitational-wave events detected with Advanced LIGO and Advanced Virgo in their first three observing runs, using the new IMRPhenomTEHM model -- a phenomenological time-domain multipolar waveform model for…

We study a massive-photon electrodynamics and magnetohydrodynamics (MHD) in the curved spacetime of Einstein's gravity. We consider a Proca-type photon mass and present equations in terms of electric and magnetic (EM) fields and the vector…

We introduce IMRPhenomTEHM, a new phenomenological time-domain model for eccentric aligned-spin binary black holes. Building upon the accurate quasi-circular IMRPhenomTHM model, IMRPhenomTEHM integrates the eccentric post-Newtonian (PN)…

Black hole entropy is identified with the counting of the dynamical degrees of freedom of trapped gravitational modes continually sourced by the Hawking-Unruh process. In the context of linear perturbations of Schwarzschild spacetime the…

We obtain the metric which describes the spacetime corresponding to the Frolov black hole in the presence of a cloud of strings and discuss how this cloud affects the regularity of the solution and the energy conditions. In addition, we…

We study a six-dimensional Kaluza-Klein theory with spacetime topology $M_4 \times S^2$ and analyze the gauge sector arising from dimensional reduction. Using normalized Killing vectors on $S^2$, we explicitly construct the reduced…