Related papers: Blackhole perturbations in the Modified Generalize…
This study delves into the existence of dark matter around supermassive black holes in galactic cores using a novel gravitational model. By analyzing gravitational waves emitted during the ringdown phase of black holes under different field…
We investigate the pseudospectrum of a Schwarzschild-like spacetime within the framework of black hole perturbation theory to analyze a counterintuitive assertion regarding the instability of quasinormal modes. Recent findings suggest that…
Gravitational waves emitted from the gravitational ringing of supermassive black holes are important targets to test general relativity and probe the matter environment surrounding such black holes. The main components of the ringing…
Any Dark Energy (DE) or Modified Gravity (MG) model that deviates from a cosmological constant requires a consistent treatment of its perturbations, which can be described in terms of an effective entropy perturbation and an anisotropic…
The current work treats cosmological perturbation in a mixture of standard matter, Chaplygin gas as well as Gauss-bonnet fluids using a 1+3 covariant approach in the context of modified $f(G)$ gravity. We define the gradient variables to…
By considering the concept of a unified single fluid model, referred to as the modified Chaplygin gas (MCG), which amalgamates dark energy and dark matter. In this study, we explore the thermodynamic characteristics of charged anti-de…
We study scalar and electromagnetic perturbations of a family of nonsingular nonrotating black hole spacetimes that are solutions in a large class of conformally invariant theories of gravity. The effective potential for scalar…
A new diagnostic method, $Om$ is applied to generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy. On the basis of the recently observed data: the Union supernovae, the observational Hubble data, the SDSS…
The cosmological model of the modified Chaplygin gas interacting with cold dark matter is studied. Our attention is focused on the final state of universe in the model. It turns out that there exists a stable scaling solution, which…
We reformulate the Chern-Simons modified gravity in the metric-affine formalism, by enlarging the Pontryagin density with homothetic curvature terms which restore projective invariance without spoiling topologicity. The latter is then…
Detailed observations of phenomena involving black holes, be it via gravitational waves or more traditional electromagnetic means, can probe the strong field regime of the gravitational interaction. The prediction of features in such…
We have assumed the FRW universe in loop quantum cosmology (LQC) model filled with the dark matter and the Generalized Cosmic Chaplygin gas (GCCG) type dark energy where dark matter follows the linear equation of state. We present the…
The static vacuum spherically symmetric solutions in massive gravity are obtained both analytically and numerically. The solutions depend on two parameters (integration constants): the mass M (or, equivalently, the Schwarzschild radius),…
We extend the equation of state of GCG (Generalized Chaplygin Gas) to $w<-1$ regime and show, from the point of view of dynamics, that the parameters of GCG should be in the range of $0<\alpha<1$. Also, dynamical analysis indicate that the…
The integration of non-commutative geometry and Gauss-Bonnet corrections in an action and the study of their black hole responses can provide highly intriguing insights. Our primary motivation for this study is to understand the interplay…
In this paper, a modified Chaplygin gas model of unifying dark energy and dark matter with exotic equation of state $p=B\rho-\frac{A}{\rho^{\alpha}}$ which can also explain the recent accelerated expansion of the universe is investigated by…
We investigate a cosmological model based on a massless nonlinear spinor field coupled to a Modified Chaplygin Gas (MCG) in the Kantowski--Sachs spacetime, aiming to probe anisotropies and unified dark sector dynamics. The model parameters…
One approach in modern cosmology consists in supposing that dark matter and dark energy are different manifestations of a single `quartessential' fluid. Following such idea, this work presents a study of the evolution of perturbations of…
Black hole ringdowns in extensions of General Relativity (GR) generically exhibit two distinct signatures: (1) theory-dependent shifts in the standard black-hole quasinormal modes, and (2) additional modes arising from extra fundamental…
In the present work, we study the causal structure of spherically symmetric black holes immersed in a Chaplygin-like dark fluid, emphasizing the impact of the fluid parameters on curvature and horizon formation. We show that the spacetime…