Large-scale suppression from stochastic inflation

Phys Rev Lett. 2010 Nov 19;105(21):211302. doi: 10.1103/PhysRevLett.105.211302. Epub 2010 Nov 16.

Abstract

We show nonperturbatively that the power spectrum of a self-interacting scalar field in de Sitter space-time is strongly suppressed on large scales. The cutoff scale depends on the strength of the self-coupling, the number of e folds of quasi-de Sitter evolution, and its expansion rate. As a consequence, the two-point correlation function of field fluctuations is free from infrared divergencies.