Unimodular f(G) gravity

Abstract

In this paper we study a modified version of unimodular general relativity in the context of f (G), G denoting the Gauss-Bonnet invariant. We focus on Bianchi-type I and Friendmann-Robertson-Walker universes and search for unimodular f (G) models according to the de Sitter and power-law solutions. Assuming unimodular f (G) gravity as a perfect fluid and making use of the slow-roll parameters, the inflationary model has been reconstructed in concordance with the Planck observational data. Moreover, we investigate the realization of the bounce and loop quantum cosmological ekpyrotic paradigms. Assuming suitable and appropriate scale factors, unimodular f (G) models able to reproduce superbounce and ekpyrotic scenarios have been reconstructed.

Nonconservative traceless type gravity

“…There are also attempts in the literature to find out unimodular versions of extended theories of gravity as for example the unimodular f (R) [2,[6][7][8], unimodular f (R, T ) [9], unimodular f (G) [10]. Another interesting similar proposal is the mimetic gravity proposed in Ref.…”

Cosmological Models with Big Rip and Pseudo Rip Scenarios in Extended Theory of Gravity

“…Houndjo et al. [ 19 ] have investigated the LR cosmology in f ( R , T ) gravity. In f ( R ) gravity, Vasilev et al.…”

Reconstruction Method in <i>F(G)</i> Gravity: Stability Study and Inflationary Survey

“…In addition to the benefit of being able to explain the present Universe acceleration of the by modifying standard theories of gravity, another major issue which will hopefully be explained in the next two decades, is the primordial post-quantum gravity era of our Universe. To date there are two candidate descriptions for this primordial era, the inflationary scenario [24]- [32] and the bouncing cosmology scenario [33] [34] [35]. Thus, in our present study, we will endeavor first to reconstruct a model in modified…”

“…Sitter's solutions, an explicit analytical expression of each of the perturbation functions in(35) and (36) respectively. And we can easily notice that for an appropriate choice of parameters, the quantities Hence these two functions converge.…”