On the Slow Roll Expansion for Brane Inflation

Abstract

One possibility for identifying the inflaton in the framework of string theory is that it is a $D$-brane modulus. This option involves a specific, non-canonical form of the kinetic energy -- the Dirac-Born-Infeld action. This note investigates the applicability of the slow roll approximation in inflationary models of this type. To this end the slow roll expansion of Liddle, Parsons and Barrow is derived for the case of the DBI action. The resulting slow roll conditions augment the standard ones valid in the case of canonical kinetic terms. It is also shown that in DBI models inflation does not require that the potential dominate the energy density.

References added

References in corpus (4)

• Observational Signatures and Non-Gaussianities of General Single Field Inflation
• Observing Brane Inflation
• DBI Inflation in the Tip Region of a Warped Throat
• Primordial Non-Gaussianity and Gravitational Waves: Observational Tests of Brane Inflation in String Theory

Cited by in corpus (23)

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• DBI models for the unification of dark matter and dark energy
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• Resurrecting the Power-law, Intermediate, and Logamediate Inflations in the DBI Scenario with Constant Sound Speed
• Enhanced Inflation in the Dirac-Born-Infeld framework
• Inflation in DBI models with constant gamma
• Inflationary universe in the presence of a minimal measurable length
• Planck Limits on Non-canonical Generalizations of Large-field Inflation Models
• Polymer inflation
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• Inflationary predictions at small gamma