Tachyonic Inflation in a Warped String Background

TL;DR

This paper explores the feasibility of tachyonic inflation within warped string backgrounds, specifically analyzing parameter constraints and potential realizations in D-brane configurations to improve upon previous limitations.

Contribution

It demonstrates that warped compactifications with D6-branes can accommodate inflationary parameters, offering a potential solution to prior challenges in string-based tachyonic inflation models.

Findings

Inflation parameters can be achieved with D6-branes in warped backgrounds.

Warped throat geometries improve parameter ranges for tachyonic inflation.

Explicit string compactification requirements are discussed.

Abstract

We analyze observational constraints on the parameter space of tachyonic inflation with a Gaussian potential and discuss some predictions of this scenario. As was shown by Kofman and Linde, it is extremely problematic to achieve the required range of parameters in conventional string compactifications. We investigate if the situation can be improved in more general compactifications with a warped metric and varying dilaton. The simplest examples are the warped throat geometries that arise in the vicinity of of a large number of space-filling D-branes. We find that the parameter range for inflation can be accommodated in the background of D6-branes wrapping a three-cycle in type IIA. We comment on the requirements that have to be met in order to realize this scenario in an explicit string compactification.