Exact vacuum solutions to modified Einstein field equations in f(R) gravity

Abstract

Considering the plane symmetric non-static spacetimes in the context of [Formula: see text] gravity, we obtain exact solutions of the vacuum field equations by assuming constant scalar curvature. By suitable transformations, it is shown that the obtained solutions can be transformed to Bianchi type [Formula: see text], a type of Taub’s and the De Sitter solutions. Of particular interest is a solution that represents a model that has initial singularity and under an appropriate transformation can be converted to a Bianchi-type V model. This solution, like the Bianchi type V model, leads to predictions about evolution in the sense of an expanding universe starting from an initial singularity. In this context, we show that the expansion of the universe in [Formula: see text] gravity can be explained without invoking the cosmological constant [Formula: see text].