Study of Generalized Lema\^{\i}tre-Tolman-Bondi Spacetime in Palatini $f(R)$ Gravity

TL;DR

This paper investigates the properties of generalized Lemaître-Tolman-Bondi spacetime within Palatini $f(R)$ gravity, deriving modified field equations, structure scalars, and analyzing their properties and similarities to classical LTB spacetime.

Contribution

It extends LTB spacetime analysis to Palatini $f(R)$ gravity, deriving new structure scalars and exploring their properties under this modified gravity framework.

Findings

Structure scalars depend on material profile similarly to classical LTB.

Generalized LTB spacetime exhibits properties comparable to standard LTB.

Derived modified field equations for dissipative dust in Palatini $f(R)$ gravity.

Abstract

This paper aims to analyze the generalization of Lema\^{\i}tre-Tolman-Bondi (LTB) spacetime for dissipative dust under the influence of Palatini $f(R)$ gravity. We explore the modified field equations, kinematical variables, and mass function in this scenario. We construct Bianchi identities using conservation and differential equations for shear, expansion, and curvature scalar in the background of Palatini $f(R)$ gravity. We calculated the scalar functions coming from the orthogonal decomposition of the Riemann tensor in this framework. These scalar functions known as structure scalars have been explored for LTB spacetime using modified field equations. The symmetric properties of LTB spacetime have been discussed using two subcases. We found that generalized LTB spacetime has properties comparable with LTB and obtained structure scalars in both cases which have a similar dependence on a material profile even in Palatini gravity.