Geometrical Tachyon Inflation in the Presence of a Bulk Tachyon Field

TL;DR

This paper investigates how a bulk tachyon field influences geometrical tachyon inflation on an unstable D3-brane, revealing modifications to the potential and conditions for early and late acceleration phases.

Contribution

It introduces a model where bulk tachyon effects modify the geometrical tachyon potential, enabling inflation at weak coupling and late acceleration.

Findings

Inflation occurs at weak string coupling with bulk tachyon condensation.

The potential is modified by a function of the bulk tachyon.

Late acceleration phase occurs when the bulk tachyon approaches zero.

Abstract

We present the study of the dynamics of the geometrical tachyon field on an unstable D3-brane in the background of a bulk tachyon field of a D3-brane solution of Type-0 string theory. We find that the geometrical tachyon potential is modified by a function of the bulk tachyon and inflation occurs at weak string coupling, where the bulk tachyon condenses, near the top of the geometrical tachyon potential. We also find a late accelerating phase when the bulk tachyon asymptotes to zero and the geometrical tachyon field reaches the minimum of the potential.