Inflation in DBI models with constant gamma
Abstract
Dirac-Born-Infeld scalar field theories which appear in the context of inflation in string theory in general have a field dependent speed of sound. It is however possible to write down DBI models which possess exact solutions characterized by a constant speed of sound different from unity. This requires that the potential and the effective D-brane tension appearing in a DBI action have to be related in a specific way. This paper describes such models in general and presents some examples with a constant speed of sound for which the spectrum of scalar perturbations can be found analytically without resorting to the slow roll approximation.
Keywords
Cite
@article{arxiv.0711.4326,
title = {Inflation in DBI models with constant gamma},
author = {Michal Spalinski},
journal= {arXiv preprint arXiv:0711.4326},
year = {2009}
}
Comments
V3: Extended and improved discussion, some new results, and additional references. V4: small improvements; same as the version published in JCAP