Eternal Chaotic Inflation is Prohibited by Weak Gravity Conjecture

TL;DR

This paper demonstrates that eternal chaotic inflation is incompatible with the weak gravity conjecture, as the effective field theory breaks down before eternal inflation can occur, and the total e-folds are limited by inflationary entropy.

Contribution

It shows that weak gravity conjecture constraints prevent eternal chaotic inflation with common potentials, providing a new theoretical limitation on inflation models.

Findings

Eternal chaotic inflation cannot occur under weak gravity conjecture.

Effective field theory breaks down before eternal inflation begins.

Total e-folds are limited by inflationary entropy.

Abstract

We investigate whether the eternal chaotic inflation can be achieved when the weak gravity conjecture is taken into account. We show that even the assisted chaotic inflation with potential $\lambda\phi^4$ or $m^2\phi^2$ can not be eternal. The effective field theory description for the inflaton field breaks down before inflation reaches the eternal regime. We also find that the total number of e-folds is still bounded by the inflationary entropy for the assisted inflation.