Stability of regular energy density in Palatini $$f(R)$$ f ( R ) gravity

Abstract

The present work explores the effects of the three-parametric f (R) model on the stability of the regular energy density of planar fluid configurations with the Palatini f (R) formalism. For this purpose, we develop a link between the Weyl scalar and structural properties of the system by evaluating a couple of differential equations. We also see the effects of Palatini f (R) terms in the formulation of structure scalars obtained by orthogonal splitting of the Riemann tensor in general relativity. We then identify the parameters which produce energy density irregularities in expansive and expansion-free dissipative as well as non-dissipative matter distributions. It is found that particular combinations of the matter variables lead to irregularities in an initially homogeneous fluid distribution. We conclude that Palatini f (R) extra corrections tend to decrease the inhomogeneity, thereby imparting stability to the self-gravitating system.

Study of Generalized Lema\^ıtre-Tolman-Bondi Spacetime in Palatini $f(R)$ Gravity

“…Herrera et al [69] considered the dissipative dust fluid as a source of gravitational radiation and have mentioned that the dissipative dust fluid is the most compatible fluid to discuss the gravitational radiations. Sharif and Yousaf [51] analyzed the factors that generate the energy density irregularities in expansion free matter distribution by considering the dissipative and non-dissipative case in Palatini f (R) gravity. They considered the particular case of dissipative dust fluid and apply certain conditions to examine the contribution of radiating parameters in the origon of energy density irregularities.…”

The Quantum Description of BF Model in Superspace

“…The BV method also address the possible violations of symmetries of the action by quantum effects. The BV formulation (independently introduced by Zinn-Justin [21]) extends the BRST approach [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. In fact, the BRST symmetry [37,38] is a very important symmetry for gauge theories [26,[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54].…”

Bianchi Type-V Bulk Viscous Cosmic String inf(R,T)Gravity with Time Varying Deceleration Parameter

“…Sharif and Yousaf [18] obtained that in addition to other fluid variables higher order ( ) corrections, relaxation processes, and electromagnetic field affect the energy density in homogeneity of spherical stars. Furthermore Sharif and Yousaf [19] explored the effects of the three-parametric ( ) model on the stability of the regular energy density of planar fluid configurations with the Palatini ( ) formalism. There exist other interesting classes of modified gravity theories such as ( ) gravity, ( , ) gravity, ( ) gravity, and ( , ) gravity.…”