广义相对论与量子宇宙学
Macroscopic observables allow the recovery of intrinsic dynamics from stationary quantum states. I show that, by interpreting the squared amplitude as the probability density for each definite value of intrinsic time, a curvature emerges in…
We perform Bayesian model selection to test for the presence of the $(\ell=2,m=0)$ spherical harmonic mode in gravitational wave events that have previously been identified as binary black hole mergers. As our signal model we use the…
This study investigates the nonlinear dynamics of a test particle near the traversable wormhole throat under an external harmonic potential. One-dimensional radial perturbation analysis shows that the particle is locally linearly stable at…
We investigate the measurability of black hole quadrupole deviations from Kerr using five binary black hole mergers observed by the LIGO-Virgo-KAGRA Collaboration with the beyond-general-relativity full-waveform model $\Psi_{\mathrm{FD}}$.…
Fermion-boson stars are compact equilibrium configurations composed of ordinary fermionic matter and a bosonic dark component interacting only through gravity. Such systems provide a natural framework for exploring deviations from standard…
Our Universe is isotropic and homogeneous when we observe it on $\gtrsim$ Mpc length scales. It is desirable that present state of the Universe has no dependence on its initial geometry. In case of Bianchi Universes, i.e., anisotropic but…
We investigate the radial motion and tidal forces experienced by neutral test particles in multi-horizon black hole solutions arising from Einstein gravity coupled to nonlinear electrodynamics (NED). Focusing on the three- and four-horizon…
Modified theories of gravity based on the symmetric teleparallel framework have recently attracted considerable attention as viable alternatives to General Relativity. In this context, f(Q) gravity, in which the gravitational interaction is…
We compute the complete renormalized stress-energy tensor (RSET) of a massless minimally coupled scalar field throughout the interior of a four-dimensional Schwarzschild black hole, in both the Unruh and Hartle--Hawking states. The complete…
We provide an explicit counterexample to the rigidity properties underlying the interpretation of mass in the presence of a positive cosmological constant $\Lambda$. Specifically, we construct a family of regular static stellar…
Testing gravity beyond general relativity (GR) is essential for probing fundamental physics in the strong-field and highly dynamical regime accessed by gravitational-wave (GW) observations. In this work, we derive analytic expressions for…
We study a static, spherically symmetric black hole obtained from Einstein gravity coupled to a nonlinear electrodynamics model with a quark--antiquark confinement interaction. The metric extends Reissner--Nordstr\"om by a logarithmic…
Within the framework of generalised entropic cosmology and its equivalent $f(Q)$ gravity, we construct inflationary scenarios consistent with recent Atacama Cosmology Telescope (ACT) observations combined with Planck-BAO data. We work with…
We investigate a class of time-dependent traversable wormholes within the framework of general relativity by allowing the shape function to vary with time. In this setting, the evolution of the geometry is directly connected to a radial…
We propose an effective, singularity-free model of the black hole interior described entirely by a scalar field with a non-linear self-interaction potential. The interior consists of three layers -- a core, a transition layer, and a crust…
In eternal black-hole spacetimes, inner horizons are Cauchy horizons and are generically unstable. For non-extremal inner horizons, this includes both the classical mass-inflation instability and a semiclassical instability associated with…
Gravitational lensing of gravitational waves can probe compact lenses, dark matter substructure, and cosmological distances, but identifying lensed events is difficult when unrelated binary mergers overlap in the same analysis window. We…
The frequency-domain gravitational waveform emitted by the scattering of two non-spinning massive particles has recently been derived at next-to-leading, \textit{i.e.} one-loop, post-Minkowskian order, $h(\omega, \theta,\phi) \sim G^2 +…
To probe the interplay between dark matter (DM) and non-linear electrodynamics (NED), we consider the Bardeen black hole (BH) surrounded by perfect fluid dark matter (PFDM). We first compute the effective potential governing the particle…
In this paper, we study the optical appearance of a 4D Einstein-Gauss-Bonnet asymmetric thin-shell wormhole. Using Visser's cut-and-paste construction, we determine the photon sphere radius and critical impact parameter for different values…