广义相对论与量子宇宙学
We study transverse vector perturbations in ghost-free extended quasidilaton massive gravity without a quasidilaton kinetic term, in the presence of minimal matter. In vacuum, we recover the known result that the kinetic coefficient $K_V$…
We investigate the quadratic-order effective energy--momentum tensor (2EMT) of scalar cosmological perturbations on uniform-density hypersurfaces during slow-roll inflation. The 2EMT is constructed from terms quadratic in the linear metric…
We investigate the thermodynamic behaviour of an AdS black hole arising from nonlinear electrodynamics-corrected gravity, incorporating quantum effects through thermal fluctuations. From the Einstein--Euler--Heisenberg framework, we…
Curvature-dependent conformal rules are local forward assignments on known metrics, but they are not generically local changes of metric variables. We study the nondegenerate class $\widetilde g_{\mu\nu}=F(R[g])g_{\mu\nu}$, with $F>0$ and…
Gravitational-wave standard sirens provide a direct measurement of luminosity distance and therefore offer a new way to test gravity over cosmological scales. We use this idea to forecast the sensitivity of the Einstein Telescope (ET) to…
We study static, spherically symmetric white dwarfs in minimal dilatonic gravity (MDG) -- a Brans-Dicke theory with fixed coupling $\alpha^2=1/3 $ and free Compton length $\lambda_{\Phi}$. Solving the full relativistic structure equations…
We develop an efficient three-dimensional numerical-relativity framework for primordial black-hole (PBH) formation from superhorizon curvature perturbations in a radiation-dominated Universe. We implement flux-conservative relativistic…
In this article we analyze the effects of a finite temperature equation of state on the equilibrium structure of white dwarfs in massive Brans-Dicke theory as well as the symmetron and dilaton screening mechanisms. We compute and present…
We investigated the thermodynamic and quantum-information cost of irreversible information erasure at the event horizon of hairy black holes generated through extended geometric deformation. Starting from the Schwarzschild black hole seed…
Within a covariant effective Hamiltonian framework, we employ an inverse construction to derive the gravitational Hamiltonian constraint for a Minkowski-core regular black hole without invoking exotic matter. We then extend the constraint…
In this work, we establish a systematic framework to describe the vacuum decays in a radiation-dominated FLRW universe from the Schwinger-Keldysh formalism. By splitting the phase transition field $\Phi$ into the mean field $\phi$ and the…
We formulate a horizon-regular double-null criterion for regular inner marginal horizons in spherically symmetric metric $f(R)$ gravity. Using normalized outgoing and ingoing radial null vectors $\ell^\mu$ and $n^\mu$, with $n^\mu$ affinely…
We extend the recently proposed modified double-copy formalism to quasitopological gravity (QTG) coupled to matter. For spherically symmetric configurations, the QTG field equations in $D-$dimensional curved spacetime with a broad class of…
We construct a two-scale, static, spherically symmetric regular black hole in Einstein gravity sourced by magnetic nonlinear electrodynamics (NED). The zero-point length $\ell$ regularizes the mass and charge profiles, whereas $q$ is the…
The distribution of dark matter in the immediate vicinity of supermassive black holes remains poorly understood despite its importance for galaxy evolution and precision tests of gravity. Future space-based gravitational-wave observatories…
In this work we investigate the tidal properties of the Dymnikova regular black hole and their ef fects on massive particles in radial free-fall. Starting from Dymnikova static, spherically symmetric solution, we derive the equations…
We study decay of a scalar field false vacuum near a (3+1)-dimensional Schwarzschild black hole equilibrated at Hawking temperature with the environment. Our scalar field model has negative quartic self-coupling and thereby resembles Higgs…
We present a stability analysis of a dark-fluid model described as a non-relativistic, rotating, non-viscous, self-gravitating fluid. We assume spherical symmetry and model the matter by a polytropic equation of state. The resulting coupled…
Within classical general relativity, we compare a sharp timelike junction and a smooth finite-width spacelike initial-data embedding of a positive-excess virialized halo in a homogeneous Lambda-FLRW environment. On the ordinary branch,…
This paper develops a phase-plane formulation of gravitational light deflection by static and spherically symmetric black holes, with Schwarzschild spacetime as the principal case. Instead of perturbing the null trajectory and locating the…