On Power Law Inflation in DBI Models

Abstract

Inflationary models in string theory which identify the inflaton with an open string modulus lead to effective field theories with non-canonical kinetic terms: Dirac-Born-Infeld scalar field theories. In the case of a $D$-brane moving in an AdS throat with a quadratic scalar field potential DBI kinetic terms allow a novel realization of power law inflation. This note adresses the question of whether this behaviour is special to this particular choice of throat geometry and potential. The answer is that for any throat geometry one can explicitly find a potential which leads to power law inflation. This generalizes the well known fact that an exponential potential gives power law inflation in the case of canonical kinetic terms.

References and comments added

References in corpus (4)

• Gauge invariant MSSM inflaton
• Escaping from the black hole?
• 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 (11)

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• DBI Inflation using a One-Parameter Family of Throat Geometries
• Bridging geometries and potentials in DBI cosmologies
• Enhanced Inflation in the Dirac-Born-Infeld framework
• Inflation in DBI models with constant gamma
• A new mechanism for non-locality from string theory: UV-IR quantum entanglement and its imprints on the CMB
• New Solutions of the Inflationary Flow Equations