Entropy production in the Early Universe. A new mechanism

Abstract

We expose briefly the role of entropy in the early universe and in particular the importance of searching for new mechanisms of entropy production. We describe a mechanism that shows how entropy is produced during early annihilations and under which conditions the production is not negligible. A MeV tau neutrino provides an interesting application.

Comments: 9 pages, Latex, 3 ps-figures included. Talk presented in the Nato School Sesion "Generation of Cosmological Large-Scale Structure" (Erice, November 1996)