M-Theory Inflation from Multi M5-Brane Dynamics

TL;DR

This paper proposes a novel inflationary model derived from M-theory involving multiple M5-branes, where assisted inflation occurs through non-perturbative membrane interactions, leading to a successful cosmological inflation scenario.

Contribution

It introduces a new M-theory based inflation model utilizing multi M5-brane dynamics and assisted inflation, with detailed mechanisms for reheating and moduli stabilization.

Findings

Achieves sufficient e-foldings for inflation.

Predicts a spectral index consistent with observations.

Demonstrates moduli stabilization post-inflation.

Abstract

We derive inflation from M-theory on S^1/Z_2 via the non-perturbative dynamics of N M5-branes. The open membrane instanton interactions between the M5-branes give rise to exponential potentials which are too steep for inflation individually but lead to inflation when combined together. The resulting type of inflation, known as assisted inflation, facilitates considerably the requirement of having all moduli, except the inflaton, stabilized at the beginning of inflation. During inflation the distances between the M5-branes, which correspond to the inflatons, grow until they reach the size of the S^1/Z_2 orbifold. At this stage the M5-branes will reheat the universe by dissolving into the boundaries through small instanton transitions. Further flux and non-perturbative contributions become important at this late stage, bringing inflation to an end and stabilizing the moduli. We find that with moderate values for N, one obtains both a sufficient amount of e-foldings and the right size for the spectral index.