Warming up brane-antibrane inflation

TL;DR

This paper demonstrates that brane-antibrane inflation can naturally occur in a warm regime with strong dissipative effects, reducing the eta-problem and enabling sufficient inflation with realistic parameters.

Contribution

It introduces a warm inflation scenario in brane-antibrane models with intersecting D-branes, showing how dissipation alleviates the eta-problem and allows for viable inflation.

Findings

Sufficient e-folds achieved with perturbative couplings and multiple branes.

Warm inflation suppresses tensor perturbations and predicts small non-Gaussianity.

Contrast with cold scenarios highlights the advantages of warm inflation in string theory models.

Abstract

We show that, in constructions with additional intersecting D-branes, brane-antibrane inflation may naturally occur in a warm regime, such that strong dissipative effects damp the inflaton's motion, greatly alleviating the associated eta-problem. We illustrate this for D3-antiD3 inflation in flat space with additional flavor D7-branes, where for both a Coulomb-like or a quadratic hybrid potential a sufficient number of e-folds may be obtained for perturbative couplings and O(10-10^4) branes. This is in clear contrast with the corresponding cold scenarios, thus setting the stage for more realistic constructions within fully stabilized compactifications. Such models generically predict a negligible amount of tensor perturbations and non-gaussianity f_NL \sim O(10).