A Note on Brane Inflation

TL;DR

This paper discusses a potential conflict in string theory models of brane inflation, highlighting issues with the string spectrum in curved space and the implications for UV completion of gravity.

Contribution

It identifies a tension between brane inflation models and the string spectrum in curved backgrounds, emphasizing the need for consistent UV completion.

Findings

Potential tension between brane inflation and string spectrum in curved space

Implication that the leading Regge trajectory must extend to the Planck scale

Highlights challenges for string theory UV completion of gravity

Abstract

This short note emphasises a potential tension between string models of inflation based on systems of branes and antibranes and the spectrum of strings in curved space, in particular the requirement that the leading Regge trajectory extends to the Planck scale allowing for the conventional string theory UV completion of gravity.