The nature of singularity in Bianchi I cosmological string gravity model with second order curvature corrections

We investigate Bianchi I cosmological model in the theory of a dilaton field coupled to gravity through a Gauss-Bonnet term. Two type of cosmological singularity are distinguished. The former is analogous to the Einstein gravity singularity, the latter (which does not appear in classical General Relativity) occurs when the main determinant of the system of field equations vanishes. An analogy between the latter cosmological singularity and the singularity inside a black hole with a dilatonic hair is discussed. Initial conditions, leading to these two types of cosmological singularity are found via numerical integration of the equation of motion. (C) 2001 Published by Elsevier Science B.V.