Infrared resummation for derivative interactions in de Sitter space

Understand

In de Sitter space, scale invariant fluctuations give rise to infrared logarithmic corrections to physical quantities, which eventually spoil perturbation theories.

• For models without derivative interactions, it has been known that the field equation reduces to a Langevin equation with white noise in the leading logarithm approximation.
• The stochastic equation allows us to evaluate the infrared effects nonperturbatively.
• We extend the resummation formula so that it is applicable to models with derivative interactions.