Weak gravity conjecture constraints on inflation

TL;DR

This paper explores how the weak gravity conjecture constrains inflation models by analyzing gravitational corrections to scalar couplings, potentially placing some models like chaotic inflation in the swampland.

Contribution

It introduces a new constraint on inflation models derived from the weak gravity conjecture, linking gravitational corrections to the validity of effective scalar theories.

Findings

A UV cutoff scale $oxed{ ext{Lambda}= ext{lambda}_4^{1/2} M_p}$ is identified for $ ext{lambda}_4 ext{phi}^4$ theory.

The weak gravity conjecture imposes bounds on scalar couplings affecting inflation models.

Chaotic inflation may be incompatible with the conjecture, placing it in the swampland.

Abstract

We consider the gravitational correction to the coupling of the scalar fields. Weak gravity conjecture says that the gravitational correction to the running of scalar coupling should be less than the contribution from scalar fields. For instance, a new scale $\Lambda=\lambda_4^{1/2}M_p$ sets a UV cutoff on the validity of the effective $\lambda_4 \phi^4$ theory. Furthermore, this conjecture implies a possible constraint on the inflation model, e.g. the chaotic inflation model might be in the swampland.