Speaker
David Wands
(ICG)
Description
I will discuss how to apply stochastic formalism for inflation beyond the usual slow-roll approximation. We verify that the assumptions on which the stochastic formalism relies still hold even far from the slow-roll attractor. In particular this requires the separate universe assumption to hold for long-wavelength perturbations of the scalar field beyond slow roll. In general, there is a gauge correction to the amplitude of the stochastic noise which is usually calculated in the spatially-flat gauge. We show that if the number of e-folds is used as the time variable (the uniform-N gauge) then these corrections vanish in the slow-roll limit, but we explain how to calculate them in general.
