On exponential cosmological type solutions in the model with Gauss-Bonnet term and variation of gravitational constant

TL;DR

This paper explores exponential cosmological solutions in a D-dimensional Gauss-Bonnet gravity model, identifying specific solutions that align with observational constraints on the variation of the gravitational constant G.

Contribution

It finds new exponential solutions with varying G in higher dimensions, including exact solutions with constant G and an infinite series consistent with observational data.

Findings

Exact solutions in D=22 and D=28 with constant G.

Infinite series of solutions in D≥2690 with G variation within observational limits.

Demonstration of exponential expansion compatible with observational constraints.

Abstract

A D-dimensional gravitational model with Gauss-Bonnet term is considered. When ansatz with diagonal cosmological type metrics is adopted, we find solutions with exponential dependence of scale factors (with respect to "synchronous-like" variable) which describe an exponential expansion of "our" 3-dimensional factor-space and obey the observational constraints on the temporal variation of effective gravitational constant G. Among them there are two exact solutions in dimensions D = 22, 28 with constant G and also an infinite series of solutions in dimensions D \ge 2690 with the variation of G obeying the observational data.