On the inflationary solutions in higher-derivative gravity with dilaton field

TL;DR

This paper investigates de Sitter inflationary solutions within string-inspired higher-derivative gravity theories involving a dilaton field, analyzing stability and special cases in four dimensions with torsion considerations.

Contribution

It identifies conditions for inflationary solutions in higher-derivative gravity with dilaton and explores their stability, including special cases with torsion in four dimensions.

Findings

Existence of de Sitter solutions in string-inspired higher-derivative gravity.

Special features of the D=4 case and ghost-free parametrization.

Inflationary solutions with torsion and dilaton in D=4.

Abstract

We discuss the existence of de Sitter inflationary solutions for the string-inspired fourth-derivative gravity theories with dilaton field. We consider a space-time of arbitrary dimension D and an arbitrary parametrization of the target space metric. The specific features of the theory in dimension D=4 and those of the special ghost-free parametrization of the metric are found. We also consider similar string-inspired theories with torsion and construct an inflationary solution with torsion and dilaton for D=4. The stability of the inflationary solutions is also investigated.