Perturbatively including inhomogeneities in axion inflation

Understand

Axion inflation, i.e.

• an axion-like inflaton coupled to an Abelian gauge field through a Chern-Simons interaction, comes with a rich and testable phenomenology.
• This is particularly true in the strong backreaction regime, where the gauge field production heavily impacts the axion dynamics.
• Lattice simulations have recently demonstrated the importance of accounting for inhomogeneities of the axion field in this regime.