Spectrum of a stochastic diffusion in an expanding universe

TL;DR

This paper analyzes the diffusion process in warm inflation models, showing that the scalar perturbation spectrum matches quantum fluctuations during exponential expansion, linking stochastic diffusion to quantum effects.

Contribution

It demonstrates the equivalence of the long wave power spectrum in warm inflation to quantum fluctuations, providing a novel connection between stochastic diffusion and quantum theory in cosmology.

Findings

Long wave power spectrum matches quantum fluctuations.

Diffusion equation derived from strong dissipation limit.

Spectrum coincides with quantum fluctuations during exponential expansion.

Abstract

We discuss the diffusion equation resulting from a strong dissipation limit of the random wave equation arising in the models of warm inflation. We show that the long wave power spectrum of scalar perturbations in the model of an exponential expansion coincides with the spectrum of quantum fluctuations on this space time.