Abstract:
We present a study of the Effective Field Theory (EFT) generalization of stochastic inflation in a modelindependent single-field framework and its impact on primordial black hole (PBH) formation. We show how the Langevin
equations for the “soft” modes in quasi de Sitter background
is described by the Infra-Red (IR) contributions of scalar perturbations, and the subsequent Fokker–Planck equation driving the probability distribution for the stochastic duration N ,
significantly modify in the present EFT picture. An explicit
perturbative analysis of the distribution function by implementing the stochastic-δN formalism is performed up to the
next-to-next-to-next-to-leading order (NNNLO) for both the
classical-drift and quantum-diffusion dominated regimes. In
the drift-dominated limit, we perturbatively analyse the local
non-Gaussianity parameters ( fNL, gNL, τNL) with the EFTinduced modifications. In the diffusion-dominated limit, we
numerically compute the probability distribution featuring
exponential tails at each order of perturbative treatment.
