Recently, a proposal to obtain finite contribution of second derivative order the gravitational field equations in \(D = 4\) dimensions from renormalized Gauss-Bonnet term action has received wave attention. It triggered discussion whether employed renormalization procedure yields well-defined theory. One main criticisms is based on fact that resulting cannot be obtained as Euler-Lagrange diffe...

First and foremost, we show that a 4-dimensional conformally flat generalized Ricci recurrent spacetime $(GR)_4$ is an Einstein manifold. We examine such as solution of $f(R, G)$-gravity theory it shown the additional terms from modification gravitational sector can be expressed perfect fluid. Several energy conditions are investigated with G) = R +\sqrt{G}$ R^2+GlnG$. For both models, weak, nu...

De Sitter solutions play an important role in cosmology because the knowledge of unstable de can be useful to describe inflation, whereas stable are often used models late-time acceleration Universe. The Einstein–Gauss–Bonnet gravity cosmological actively both as inflationary and dark energy models. To modify Einstein equations one add a nonlinear function Gauss–Bonnet term or scalar field mult...