General Relativity and Quantum Cosmology
We consider a spatially flat cosmological model containing a noninteracting barotropic fluid and holographic dark energy with the future event horizon as the infrared cutoff. We parametrize the deviation of the horizon entropy from the…
Dark matter deficient galaxies provide a direct way to test whether baryons and dark matter can become sufficiently separated during galaxy evolution. We formulate a Dark Matter-Baryon Separability condition based on the relative…
Numerical simulations of gravitational waves (GW) production during violent evolution of matter inhomogeneities in the early Universe yield highly wiggle infrared parts of the spectra. Obtained directly from the two-point correlation…
We construct the exterior coupled gravitational and electromagnetic response of a magnetically supported generalized Hayward black hole within a specified nonlinear electrodynamic completion. Both parity sectors reduce to canonical two…
We present a neural network surrogate model that emulates the NRSur7dq4 gravitational waveform model for precessing binary black hole mergers. The surrogate decomposes the waveform into constituent quantities and trains an independent…
Tidal deformation of a compact object serves as a sensitive probe of the strong-gravity regime and nature of the compact object. It captures how a compact object responds to the external perturbing field of a companion. In realistic…
We revisit the derivation of the diffraction integral, which is an approximate evaluation of the Kirchhoff integral, widely used in the literature for phenomenological applications in gravitational lensing. We propose a systematic approach…
We investigate phenomenological effects induced by a noncommutative deformation of Einstein--Rosen gravitational-waves within the framework of the Riemannian geometry of noncommutative surfaces developed by Chaichian et al. Considering a…
I investigate the behaviour of the Higgs field in Schwarzschild spacetime by introducing a Planck-suppressed coupling between the Higgs field and the Kretschmann scalar, the leading curvature invariant in Ricci-flat geometries. I show that…
The origin of black hole entropy remains one of the deepest mysteries in modern physics. Two recent developments offer complementary perspectives on this puzzle: the entropy release from regular Schwarzschild black holes with a de Sitter…
We develop the cosmological framework for Hassan--Schmidt-May multi-gravity, a ghost-free extension of bimetric theory with genuinely non-pairwise interactions of multiple spin-2 fields. For metrics that are simultaneously homogeneous and…
The Magnusian is a phase-space function that generates finite-time evolution through nested Poisson brackets. It is related to several familiar generators of classical dynamics, including the radial action, the eikonal phase and related…
We study the inflationary primordial perturbations in $\kappa$-Minkowski non-commutative space-time, a Lie-algebraic type deformation of canonical space-time motivated by quantum gravity scenarios. Employing the $\kappa$-deformed star…
We establish exact analytical thresholds and present a unified thermodynamic state-space representation for the regular Hayward black hole, resolving the full phase structure without reliance on numerical approximations. By evaluating the…
We investigate gravitational wave (GW) emission from periodic timelike orbits of a test particle around a magnetized Ernst black hole and the gravitational waveforms generated by their orbital dynamics. The bound geodesics are…
We study a Schwarzschild-like black hole embedded in an exponential-sphere (ESM) dark matter halo, characterized by a halo mass $M_0$ and a scale radius $r_0$. We first show that the halo's effect on the marginally bound orbit (MBO) and…
Under the assumption that black hole horizon area is quantized, each Hawking evaporation step, during which the black hole loses mass and transitions to a lower area level, is interpreted as the erasure of one bit of information. In this…
We investigate the quasinormal modes (QNMs) of scalar perturbations and strong cosmic censorship (SCC) in regular Ay\'on-Beato-Garc\'ia-Bronnikov-de Sitter (ABGB-dS) black hole spacetime. The main motivation of this work is to clarify…
In this work, we study the gravitational lensing of gravitational waves (GWs) by extending the geometric-optics approximation to higher order. With the help of the Newman-Penrose formalism, we reexpress the GW propagation equations as a…
We constrain the Emergent Fractional Fractal (EFF) cosmological model through a joint likelihood analysis of recent cosmological observations at the background and perturbation levels. In this framework, an effective fractal dimension $d$…