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 a transition from a slow inflationary phase to a standard inflationary period based on the scale factor.

Contribution

It provides a detailed analysis of brane-universe dynamics in a type 0 string background, highlighting the induced energy density and inflationary behavior during evolution.

Findings

Effective energy density dominated by a slow varying term during early evolution.

Transition to a constant energy density indicating standard inflation.

Identification of parameter ranges for different inflationary phases.

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. We find that for some typical values of the parameters 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 $\frac{1}{(loga)^{4}}$ indicating a slow varying inflationary phase. For larger values of the scale factor the effective energy density takes a constant value and the brane-universe enters its usual inflationary period.