Related papers: Cosmic acceleration with bulk viscosity in modifie…
In this paper, we have presented an accelerating cosmological model of the Universe in an extended symmetric teleparallel gravity or $f(Q,T)$ gravity. The parametric form of the Hubble parameter is, $H\left(z\right) =H_{0}\left[ \alpha…
We study cosmologies in modified theories of gravity considering Lagrangian density $f(R)$ which is a polynomial function of scalar curvature ($R$) in the Einstein-Hilbert action in vacuum. The field equation obtained from the modified…
This paper studies the cosmology of accelerating expansion of the universe in modified teleparallel gravity theory. We discuss the cosmology of $f(T,B)$ gravity theory and its implication to the new general form of the equation of state…
In this work, we propose a new model that combines holographic dark energy with modified gravity $f(Q,T)$ to explore a possible explanation for the accelerated expansion of the universe. Since there are several tensions of cosmological…
This study combines theoretical advancements with observational limitations to investigate the cosmological implications of a bulk viscous modified Chaplygin gas (MCG) in a Friedmann--Robertson--Walker (FRW) in (3+1) dimensional spacetime…
In this research work, we explore the late-time accelerated expansion of the universe within the framework of modified gravity, specifically $f(R, L_m)$ theory, by considering two non-linear models: $f(R, L_{m}) = \frac{R}{2}+(1+\eta R)…
In this paper, we have presented bulk viscous cosmological model of the universe in the modified gravity theory in which the Lagragian of the gravitational action contains a general function $f(R, T) $, where $R$ and $T$ denote the…
The phantom dark energy remarkably boosts our prehension of the accelerating Universe. Various models are widely discussed in the phantom Universe without bulk viscosity. From the hydrodynamics' point of view, it is natural to introduce the…
In the context of dark energy solutions, we consider a Friedmann-Robertson-Walker spacetime filled with a non-interacting mixture of dust and a viscous fluid, whose bulk viscosity is governed by the nonlinear model proposed in [15]. Through…
This thesis explores the late-time cosmic acceleration within the framework of $f(R,T)$ gravity, a general relativity modification that incorporates the Ricci scalar $R$ and the trace of the energy-momentum tensor $T$. Motivated by…
In this research paper, we explore a well-motivated parametrization of the time-dependent deceleration parameter, characterized by a cubic form, within the context of late time cosmic acceleration. The current analysis is based on the…
This thesis investigates late-time cosmic acceleration using modified gravity theories with a focus on $f(Q)$ gravity, as an alternative to the $\Lambda$CDM model. The standard cosmological model attributes the acceleration to a…
We investigate the cosmological implications of $f(Q)$ gravity, which is a modified theory of gravity based on non-metricity, in non-flat geometry. We perform a detailed dynamical-system analysis keeping the $f(Q)$ function completely…
The purpose of the present work is two folded: (1) we propose a new mechanism for the origin of bulk viscosity in cosmological context, and then, (2) we address the thermodynamic implications of viscous cosmology based on the thermodynamics…
Modified theories of gravity encompass a class of $f(R)$-models that seek to elucidate the observed late time accelerated expansion of the universe. In this study, we examine a set of viable $f(R)$ models (Hu-Sawicki: two cases,…
In this study, we explored late-time cosmology within an extended class of theories based on $f(Q, L_m)$ gravity. This theory generalizes $f(Q)$ gravity by incorporating a non-minimal coupling between the non-metricity $Q$ and the matter…
In this letter, we investigate the cosmic expansion scenario of the universe in the framework of $f(R,L_m)$ gravity theory. We consider a non-linear $f(R,L_m)$ model, specifically, $f(R,L_m)=\frac{R}{2}+L_m^n + \beta$, where $n$ and $\beta$…
In a spatially flat Friedmann-Lema\^{i}tre-Robertson-Walker universe, we investigate a unified cosmic fluid scenario endowed with bulk viscosity in which the coefficient of the bulk viscosity has a power law evolution. The power law in the…
We discuss a cosmology in which cold dark-matter particles decay into relativistic particles. We argue that such decays could lead naturally to a bulk viscosity in the cosmic fluid. For decay lifetimes comparable to the present hubble age,…
The possibility that the present acceleration of the universe is driven by a kind of viscous fluid is exploited. At background level this model is similar to the generalized Chaplygin gas model (GCGM). But, at perturbative level, the…