General Relativity and Quantum Cosmology
We investigate dark matter admixed neutron stars in which the neutron star coexists with an anisotropic dark matter halo described by the Einasto density profile, a model recently shown to produce regular, singularity-free black hole…
We investigate timelike particle dynamics, collision energetics, and photon frequency shifts in the perturbative variable-scalar curvature branch of asymptotically flat symmergent gravity. The low-energy vacuum action contains an $R^{2}$…
We present a unified study of scalar, vector, and tensor quasinormal modes (QNMs) of Schwarzschild black holes corrected by a Gauss--Bonnet (GB) term in higher dimensions. Using a high-precision Chebyshev spectral method, we map the QNM…
We compute the lowest radial mode of spherically symmetric boson stars along equilibrium branches with a fixed number of radial nodes, considering both mini boson stars and quartically self-interacting models. By reformulating the pulsation…
Extreme-mass-ratio inspirals (EMRIs) encode more than $10^5$ strong-field orbital cycles and are key targets for space-borne gravitational-wave interferometers, yet coherent recovery of generic systems over astrophysically broad priors…
Modern physics has achieved extraordinary empirical success while retaining much of the absolute, unobservable structure introduced by Newton, largely without questioning its necessity. We investigate how far this structure can be…
We construct a novel Kerr-like black hole solution embedded in a general double power law dark matter environment by applying the Newman--Janis algorithm to a Schwarzschild-like seed geometry. This framework provides a unified rotating…
We study black hole formation resulting from the collapse of a homogeneous and isotropic dust ball within a framework built upon loop quantum cosmology. Using loop dynamics formulated for Lemaitre-Tolman-Bondi spacetimes---which reduce to…
The tidal response of neutron stars during binary inspiral encodes the equation of state (EOS) of dense matter in the gravitational-wave signal. Quantifying the signal-to-noise ratio (SNR) required to distinguish competing EOS models with…
In this paper we construct the canonical harmonic coordinates of the Kerr metric within the multipolar post-Minkowskian (MPM) formalism to the fourth post-Minkowskian (4PM) order. Based on the well known Geroch--Hansen moments of Kerr…
We derive and test kinematic upper bounds on charged energy extraction in the purely electric branch of a static $f(R,T)$ black hole family sourced by an Euler--Heisenberg type nonlinear electromagnetic sector. The analysis is restricted to…
We develop a quantitative framework for charge assisted Penrose extraction in Reissner--Nordstr\"om Anti-de Sitter black holes surrounded by a Kiselev type anisotropic dark energy sector. The generalized electrostatic ergosphere is defined…
In the last few decades, singularity-free black holes (BHs) obtained in the framework of Loop Quantum Gravity (LQG) have gained attention in the literature. These compact objects replace the classical singularity with a transition…
We compute the optical appearance of a maximally extended (eternal) Schwarzschild black hole surrounded by a geometrically thin accretion disk. Unlike astrophysical black holes formed by gravitational collapse, the eternal solution contains…
Near-extremal black holes can amplify higher-derivative corrections to general relativity, making them sharp probes of the perturbative control of gravitational effective field theory. We study this question in quadratic gravity with a…
Seismic Newtonian noise, arising from fluctuating gravitational forces on detector test masses due to ambient seismic activity, represents a fundamental sensitivity limit for low-frequency gravitational-wave observatories such as the…
We investigate quintessential inflation in a nonminimally coupled scalar-tensor theory, parameterizing the post-inflationary radiation abundance independently of the reheating mechanism. The nonadiabatic inflation-kination transition…
Static tidal Love numbers of four-dimensional Schwarzschild black holes vanish in general relativity, whereas higher-curvature interactions can generate a nontrivial response. We investigate the parity-even cubic Weyl correction directly in…
We investigate dynamical, time-evolving dark-energy models exhibiting phantom behaviour within Einstein gravity by analysing the evolution of matter perturbations. In particular, we consider five dark-energy parameterisations that predict a…
The gauge structure of the Weyl Gravitoelectromagnetic (GEM) formalism has been investigated, showing that although the theory admits additional propagating modes, only an effective spin-2 sector contributes to physical observables.…