Examples of exact exponential cosmological solutions with three isotropic subspaces in the Einstein-Gauss-Bonnet gravity

TL;DR

This paper presents new exact exponential solutions in higher-dimensional Einstein-Gauss-Bonnet gravity with three isotropic subspaces, describing models with three distinct Hubble-like parameters and their implications for cosmological factor spaces.

Contribution

It introduces novel exact solutions with three non-coinciding Hubble-like parameters in higher-dimensional Einstein-Gauss-Bonnet models, expanding the set of known cosmological solutions.

Findings

Exact solutions with three constant Hubble-like parameters are constructed.

Solutions involve three factor spaces including our 3D universe and internal subspaces.

Models accommodate dimensions m ≥ 3, k1 > 1, k2 ≥ 1.

Abstract

We consider $(1+ 8)$- and $(1+10)$-dimensional Einstein-Gauss-Bonnet models with the cosmological $\Lambda$-term. Some new examples of exact solutions with three constant Hubble-like parameters in this model are obtained, governed by three non-coinciding Hubble-like parameters: $H \neq 0$, $h_1$ and $h_2$, obeying $m H + k_1 h_1 + k_2 h_2 \neq 0$, corresponding to factor spaces of dimensions $m\geqslant 3$, $ k_1 > 1$ and $ k_2\geqslant 1$. In this case, the multidimensional cosmological model deals with three factor spaces: the external 3-dimensional "our" world and internal subspaces with dimensions $ (m-3)$, $k_1$ and $k_2$.