One-loop effective action for non-local modified Gauss-Bonnet gravity in de Sitter space

TL;DR

This paper explores the classical and quantum aspects of non-local modified Gauss-Bonnet gravity in de Sitter space, revealing solutions for early and late universe acceleration, and deriving the one-loop effective action relevant for the cosmological constant problem.

Contribution

It introduces a local scalar-Gauss-Bonnet representation of non-local gravity, finds de Sitter solutions for inflation and late-time acceleration, and computes the one-loop effective action in this context.

Findings

Identified de Sitter solutions corresponding to inflation and late-time acceleration.

Developed a Chameleon mechanism ensuring compatibility with gravitational tests.

Derived the explicit one-loop effective action for the theory in de Sitter space.

Abstract

We discuss the classical and quantum properties of non-local modified Gauss-Bonnet gravity in de Sitter space, using its equivalent representation via string-inspired local scalar-Gauss-Bonnet gravity with a scalar potential. A classical, multiply de Sitter universe solution is found where one of the de Sitter phases corresponds to the primordial inflationary epoch, while the other de Sitter space solution--the one with the smallest Hubble rate--describes the late-time acceleration of our universe. A Chameleon scenario for the theory under investigation is developed, and it is successfully used to show that the theory complies with gravitational tests. An explicit expression for the one-loop effective action for this non-local modified Gauss-Bonnet gravity in the de Sitter space is obtained. It is argued that this effective action might be an important step towards the solution of the cosmological constant problem.