D-brane Inflation

TL;DR

This paper presents a calculable model of brane inflation where parallel D-branes attract each other, leading to a slow-roll inflationary phase with specific spectral index and reheating mechanisms.

Contribution

It introduces a concrete brane inflation scenario with detailed calculations of inflation dynamics and observable predictions, advancing the understanding of string-inspired cosmology.

Findings

Spectral index approximately 0.97

Effective compactification scale around 10^{12} GeV

Reheating via brane collision and annihilation

Abstract

We discuss a calculable version of brane inflation, in which a set of parallel D-brane and anti-D-brane worlds, initially displaced in extra dimension, slowly attract each other. In the effective four-dimensional theory this slow motion of branes translates into a slow-roll of a scalar field (proportional to their separation) with a flat potential that drives inflation. The number of possible e-foldings is severely constrained. The scalar spectral index is found to be 0.97, while the effective compactification scale is of order $10^{12}$ GeV. Reheating of the Universe is provided by collision and subsequent annihilation of branes.