Some uses of $\zeta-$regularization in quantum gravity and cosmology

Abstract

This is a short guide to some uses of the zeta-function regularization procedure as a a basic mathematical tool for quantum field theory in curved space-time (as is the case of Nambu-Jona-Lasinio models), in quantum gravity models (in different dimensions), and also in cosmology, where it appears e.g. in the calculation of possible `contributions' to the cosmological constant coming through manifestations of the vacuum energy density. Part of this research was carried out in fruitful and enjoyable collaboration with people from Tomsk State Pedagogical University.