Lattice Simulations of Axion-U(1) Inflation

Understand

We present the first nonlinear lattice simulation of an axion field coupled to a U(1) gauge field during inflation.

• We use it to fully characterize the statistics of the primordial curvature perturbation {\zeta}.
• We find high-order statistics to be essential in describing non-Gaussianity of {\zeta} in the linear regime of the theory.
• On the contrary, non-Gaussianity is suppressed when the dynamics becomes nonlinear.