Enhancement of the Axion Decay Constant in Inflation and the Weak Gravity Conjecture

Understand

Models of axion inflation based on a single cosine potential require the axion decay constant $f$ to be super-Planckian in size.

• However, $f > M_{Pl}$ is disfavored by the Weak Gravity Conjecture (WGC).
• It is then pertinent to ask if one can construct axion inflation models in conformity with WGC.
• In this work we assume that WGC holds for the microscopic Lagrangian so that $f < M_{Pl}$.