Warped Wilson Line DBI Inflation

TL;DR

This paper introduces a new string theory inflation model where the inflaton is a Wilson line in a warped flux compactification, utilizing nonstandard DBI kinetic terms to relax constraints and potentially produce observable gravitational waves.

Contribution

It extends Wilson line inflation to a DBI framework, providing a novel inflationary scenario with relaxed observational constraints and the possibility of detectable gravitational waves.

Findings

Potential for observable gravitational waves.

Relaxed constraints compared to standard DBI inflation.

Extension of Wilson line inflation to a DBI setting.

Abstract

We propose a novel inflationary scenario in string theory in which the inflaton field is a 'Wilson line' degree of freedom in the worldvolume of a probe Dp-brane, in a warped flux compactification. Kinetic terms for Wilson line fields on the world volume of a D-brane take a nonstandard Dirac-Born-Infeld (DBI) form. Thus, we work in the framework of DBI inflation. This extends the original slow roll Wilson line inflationary scenario, where only the quadratic piece was considered. Warped DBI Wilson line inflation offers an attractive alternative to ordinary (position field) DBI inflation, inasmuch as observational and theoretical constraints get considerably relaxed. Besides the standard large non-Gaussianities in DBI scenarios, it is also possible to achieve an observable amount of gravitational waves.