The Nature of Singularity in Bianchi I Cosmological String Gravity Model with Second Order Curvature Corrections

TL;DR

This paper explores the nature of singularities in a Bianchi I cosmological model with string-inspired curvature corrections, identifying two types of singularities, including a novel one absent in classical General Relativity.

Contribution

It introduces a new type of cosmological singularity arising from second order curvature corrections in string gravity, expanding understanding of singularity behavior in such models.

Findings

Two types of singularities identified in the model.

A novel singularity occurs when the system's main determinant vanishes.

Initial conditions leading to each singularity are numerically determined.

Abstract

We investigate Bianchi I cosmological model in the theory of a dilatonM field coupled to gravity through a Gauss-Bonnet term. Two type ofM cosmological singularity are distinguished. The former is analogous toM the Einstein gravity singularity, the latter (which does not appear inM classical General Relativity) occurs when the main determinant of theM system of field equations vanishes. An analogy between the latterM cosmological singularity and the singularity inside a black hole withM a dilatonic hair is discussed. Initial conditions, leading to theseM two types of cosmological singularity are found via numericalM integration of the equation of motion.