AUTHOR: Apostolos Beligiannis

ADDRESS: Department of Mathematics,
         University of the Aegean,
         83200 Karlovassi, Samos, Greece.

ABSTRACT: Our aim in this paper is to investigate and compare
various algebraic homotopy theories defined in a natural way in a
module category. We apply our results to Gorenstein rings.

CURRENT STATUS: Preprint.
                To appear in Mathematica Scandinavica.