Rees algebras of modules and coherent functors

Abstract

We show that several properties of the theory of Rees algebras of modules become more transparent using the category of coherent functors rather than working directly with modules. In particular, we show that the Rees algebra is induced by a canonical map of coherent functors.Comment: 15 pages. This is an extended part of an old version of arXiv:1402.3219 - v2: Clarified some statements and made minor notation change