Evolution of non-flat cosmos via GGPDE f(R) model

Abstract

This paper is devoted to explore the cosmic evolution of non-flat Friedmann Robertson Walker universe through generalized ghost pilgrim dark energy model in the background of f (R) gravity. For this purpose, we consider two well known scale factors, i.e., power-law and unified scale factors in terms of red shift parameter. For these scale factors, we reconstruct the given dark energy model in f (R) gravity and determine its stability/instability through squared speed of sound parameter. In order to discuss the behavior of reconstructed and dark energy models, we evaluate well known cosmological parameter such as equation of state parameter along with ω-ω plane. In addition to this, we also investigate compatibility of new models with standard cosmological models through state-finder parameters. The density parameter is formulated for both ordinary matter as well as dark energy components and results are compared with Planck 2018 constraints. It is concluded that cosmological parameters reveal consistency with recent observations while the value of density parameter suggested by Planck 2018 is achieved by power-law scale factor in most of the cases as compared to unified scale factor.

Vacuum Energy in Saez-Ballester Theory and Stabilization of Extra Dimensions

“…For an exactly flat universe, Ω = 1 [94][95][96]. Recently, many authors advocate against the belief of an exactly flat universe [94,[97][98][99]. It will be a right conclusion to say that the universe is close to or nearly flat, but not exactly flat [94,99,100].…”

Dynamics and Stability via Thin‐Shell of Approximated Black Holes in f(Q)$f(\mathbb {Q})$ Gravity

“…Stable thin‐shell WHs are also presented from different spherical BH spacetimes for variable EoS. [ 18–23 ]…”

“…[32]. The gravastar models by considering noncommutative effects, [ 33 ] higher‐dimensional spacetimes, [ 34 ] Kuchowicz metric potential, [ 35 ] regular and charged quintessence BHs with variable EoS [ 36–42 ] have been explored with appearance of stable configurations.…”

“…[ 62–71 ] Here, many researchers explored the stability of the shell around the WH geometry in different modified theories of gravity by using different equations of stats. [ 72–82 ]…”