Failure of the stochastic approach to inflation beyond slow-roll
read the original abstract
After giving a pedagogical review we clarify that the stochastic approach to inflation is generically reliable only at zeroth order in the (geometrical) slow-roll parameter $\epsilon_1$ if and only if $\epsilon_2^2\ll 6/\epsilon_1$, with the notable exception of slow-roll. This is due to the failure of the stochastic $\Delta N$ formalism in its standard formulation. However, by keeping the formalism in its regime of validity, we showed that, in ultra-slow-roll, the stochastic approach to inflation reproduces the power spectrum calculated from the linear theory approach.
This paper has not been read by Pith yet.
Forward citations
Cited by 3 Pith papers
-
A consistent formulation of stochastic inflation I: Non-Markovian effects and issues beyond linear perturbations
The conventional truncation in stochastic inflation is inconsistent because quadratic-noise contributions are the same perturbative order as the deterministic non-Markovian corrections.
-
Nonperturbative stochastic inflation in perturbative dynamical background
Derives stochastic equations from Schwinger-Keldysh formalism that include quantum diffusion and classical metric perturbations for non-perturbative ultra-slow-roll inflation, validated on Starobinsky and critical Hig...
-
Inflaton perturbations through an Ultra-Slow Roll transition and Hamilton-Jacobi attractors
Numerical solutions of the Mukhanov-Sasaki equation for inflaton perturbations across a slow-roll to ultra-slow-roll transition are well described by Hamilton-Jacobi theory when appropriate solution branches and a par...
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.