The possible role of elementary particle physics in cosmology

Abstract

This is a review which is concerned with the following topics. a) the thermodynamical behaviour of a system of particles at ultra high temperatures, including Hagedorn's suggestion for the existence of an absolute upper limit to the temperature together with the discussion of phase transitions which could lead to particle-antiparticle separation, b) the astrophysical consequences of these effects in the framework of an evolutionary isotropic universe and their relevance to the problems of the origin of matter and galaxies.