Theory HEP Seminar

A Terminal Velocity on the Landscape - Particle Production near Extra Species Loci in Higher Dimensions

Thorsten Battefeld

Princeton University

I investigate particle production near extra species loci (ESL) in a higher dimensional field space and derive a speed limit in moduli space at weak coupling. This terminal velocity is set by the characteristic ESL-separation and the coupling of the extra degrees of freedom to the moduli, but it is independent of the moduli`s potential if the dimensionality of the field space is considerably larger than the dimensionality of the loci. Once the terminal velocity is approached, particles are produced at a plethora of nearby ESLs, preventing a further increase in speed via their backreaction. It is possible to drive inflation at the terminal velocity, providing a generalization of trapped inflation with attractive features: more than sixty e-folds of inflation for sub-Planckian excursions in field space are possible if ESLs are ubiquitous, without fine tuning of the initial speed and less tuned potentials. I present a simple, observationally viable model as a proof of concept with a slightly red scalar power-spectrum and suppressed gravitational waves and comment on the presence of additional observational signatures.