The fate of (phantom) dark energy universe with string curvature corrections

TL;DR

This paper investigates how higher-order string curvature corrections influence the evolution and ultimate fate of a dark energy universe, revealing that the universe's end state depends on the specific string theory model.

Contribution

It introduces the effects of string curvature corrections on dark energy universe evolution, highlighting differences between string types and their impact on cosmic fate.

Findings

Stable de-Sitter points with cosmological constant in heterotic and bosonic strings.

Big Crunch singularity in type II string case.

Big Rip singularity in heterotic and bosonic strings.

Abstract

We study the evolution of (phantom) dark energy universe by taking into account the higher-order string corrections to Einstein-Hilbert action with a fixed dilaton. While the presence of a cosmological constant gives stable de-Sitter fixed points in the cases of heterotic and bosonic strings, no stable de-Sitter solutions exist when a phantom fluid is present. We find that the universe can exhibit a Big Crunch singularity with a finite time for type II string, whereas it reaches a Big Rip singularity for heterotic and bosonic strings. Thus the fate of dark energy universe crucially depends upon the type of string theory under consideration.