Ulrich modules over Cohen-Macaulay local rings with minimal multiplicity

Abstract

Let R be a Cohen-Macaulay local ring. In this paper we study the structure of Ulrich $R$-modules mainly in the case where R has minimal multiplicity. We explore generation of Ulrich R-modules, and clarify when the Ulrich R-modules are precisely the syzygies of maximal Cohen-Macaulay R-modules. We also investigate the structure of Ulrich R-modules as an exact category.