广义相对论与量子宇宙学

We study primordial-black-hole (PBH) dark matter in the two-dark-dimensions (2DD) framework, a six-dimensional brane-world scenario with two compact extra dimensions and a fundamental gravity scale of order $10\,\mathrm{TeV}$. We calculate…

We investigate the dynamics of a charged massive scalar field around Kerr-Bertotti-Robinson Black Holes. By mapping the Klein-Gordon equation into a one-dimensional Schr\"odinger-like form and employing matched asymptotic expansions, we…

It is well known that the Einstein-scalar system of general relativity can in principle yield non-unique exact spinning naked singularities, which lead to unique Kerr black hole when the scalar field is switched off. It is a challenging…

We compute $\langle\hat{\Phi}^{2}\rangle_\text{ren}$ as well as the energy fluxes $\langle \hat{T}_{uu}\rangle_\text{ren}$ and $\langle \hat{T}_{vv}\rangle_\text{ren}$ (where $u$ and $v$ are the standard Eddington-Finkelstein coordinates)…

The hoop conjecture, due to Thorne, is a fundamental aspect of black holes in classical general relativity. Recently, generalized classes of regular spherically symmetric static black holes with arbitrary exponents coupled to nonlinear…

It is well-established that the Minkowski limit of pure $f(R)=R^2$ gravity breaks down, unlike that of full Starobinsky theory $f(R)=R+\alpha R^2$. We provide a novel interpretation of this phenomenon using the recent thermal analogy…

The dark shadow cast by a black hole, determined by the outermost unstable null circular geodesics (the photon sphere), provides a direct probe of strong-field gravity. In this work, we derive model-independent lower and upper bounds on the…

We propose a Lagrangian formulation for a non-conservative gravity model in which the divergence of the energy-momentum tensor in curved spacetime does not vanish. This is accomplished by introducing an arbitrary vector field that couples…

To answer the question posed in the title, we consider a novel diagnostic, viz., the difference in the times of arrival (TOA) at the observer of two light rays that simultaneously emanate from a source behind a spinning lens and pass by…

Increasing the circulating power in gravitational-wave detectors to the megawatt level is essential for future sensitivity improvement, but this is critically limited by optomechanical parametric instabilities. Current mitigation strategies…

The reverse isoperimetric conjecture asserts that, at fixed thermodynamic volume, Schwarzschild--AdS black holes maximize entropy. We prove that this statement is the fixed-volume form of a boundary-completed Noether-charge stability…

We provide a semi-analytic calculation of the first quantum corrections to the symmetron fifth force around a planar source with nonzero thickness. We find a suppression of the fifth force compared with the classical prediction within a…

We 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 equation along a geodesic congruence in…

We develop a general framework to characterize non-vacuum perturbations to relativistic binaries in the gravitational-wave (GW) driven regime, for use in GW parameter estimation studies. The effect of smooth, structured and stochastic…

Following the landmark acquisition of the first image of a black hole, systems comprising a black hole enveloped by a dark matter halo have have attracted considerable attention. This work implements a novel method to analyze the structure…

We study how dark matter (DM) impacts the crust and the spectrum of torsional crust oscillations of dark-matter-admixed neutron stars (DANSs). We construct two-fluid equilibrium solutions wherein baryonic and DM interact gravitationally…

We investigate the thermodynamic role of asymptotic aether alignment for universal horizons in Einstein-aether theory. In the static, spherically symmetric, asymptotically AdS sector with $c_{14}=0$, the known first law for universal…

This work investigates how torsion and nonmetricity modify tidal accelerations in metric-affine gravity. We derive a projected deviation equation that generalizes the standard geodesic deviation equation to metric-affine geometry, and apply…

We report on numerical simulations of critical phenomena in the collapse of axisymmetric vacuum gravitational waves, adopting families of initial data that, to the best of our knowledge, have not been used in this context before. Like…

Extreme mass-ratio inspirals (EMRIs) are among the prime sources for future space-borne gravitational wave (GW) observatories and provide a useful setting for testing the presence of fundamental fields and possible deviations from general…