Algebra/Topology Seminar

Speaker: Peder Thompson (NTNU)

Title: Minimal semi-flat-cotorsion replacements and cosupport.

Abstract: Let R be a commutative noetherian ring of finite Krull dimension. This talk introduces the notions of flat cotorsion R-modules and cosupport, and the goal will be to give a precise link between the two. In particular, we describe minimal complexes of flat cotorsion R-modules in a manner similar to working with minimal complexes of finitely generated projective modules over a local ring. Further, we show that every complex has a "minimal semi-flat-cotorsion replacement" in the derived category over R, and that this can be used to compute cosupport of most complexes. This talk is based on joint work with Tsutomu Nakamura.