Cosmological Evolution of a Brane Universe in a Type 0 String Background

TL;DR

This paper investigates the cosmological evolution of a D3-brane universe within a type 0 string background, revealing inflationary phases driven by brane motion and background fields, with implications for early universe cosmology.

Contribution

It introduces a model of brane cosmology in a type 0 string background, analyzing inflationary phases induced by brane motion and background field variations.

Findings

Inflationary phase appears for constant tachyon and dilaton.

Slowly varying inflation occurs with non-constant tachyon and dilaton.

Effective energy density dominated by a logarithmic term.

Abstract

We study the cosmological evolution of a D3-brane Universe in a type 0 string background. We follow the brane universe along the radial coordinate of the background and we calculate the energy density which is induced on the brane because of its motion in the bulk. For constant values of tachyon and dilaton an inflationary phase is appearing. For non constant values of tachyon and dilaton and for a particular range of values of the scale factor of the brane-universe, the effective energy density is dominated by a term proportional to $\frac{1}{(\log\alpha)^{4}}$ indicating a slowly varying inflationary phase.