De Sitter and Power-law Solutions in Non-local Gauss-Bonnet Gravity

TL;DR

This paper explores the cosmological solutions of a non-local Gauss-Bonnet gravity model, identifying conditions for de Sitter solutions and finding a model that describes the matter-dominated universe phase.

Contribution

It derives fixed points and conditions for de Sitter solutions in non-local Gauss-Bonnet gravity, and identifies a specific model for matter-dominated cosmology.

Findings

De Sitter solutions exist under specific parameter conditions.

Models with de Sitter solutions do not admit power-law solutions.

A particular model describes the matter-dominated universe phase.

Abstract

The cosmological dynamics of a non-locally corrected gravity theory, involving a power of the inverse d'Alembertian, is investigated. Casting the dynamical equations into local form, the fixed points of the models are derived, as well as corresponding de Sitter and power-law solutions. Necessary and sufficient conditions on the model parameters for the existence of de Sitter solutions are obtained. The possible existence of power-law solutions is investigated, and it is proven that models with de Sitter solutions have no power-law solutions. A model is found, which allows to describe the matter-dominated phase of the Universe evolution.