Speaker
Description
Previous work on Stochastic Inflation in full General Relativity is extended to any dark energy model described by the Effective Field Theory of Dark Energy. The recipe to obtain the dynamics of a any such nonlinear and nonperturbative long-wavelength scalar-tensor theory, when dynamically sourced by classicalised fluctuations of the short modes, is explained, proved and illustrated with a few examples of matchings. These include Gauss-Bonnet, Brans-Dicke, Horndeski theories and beyond. The separate universe approximation is also provided and commented for each of those. A final discussion on the validity of the approach is provided, as well as other natural extensions to provide a phenomenologically complete stochastic framework, and potential applications beyond the realm of inflation.