Coherent rings, fp-injective modules, dualizing complexes, and covariant Serre-Grothendieck duality

Abstract

For a left coherent ring A with every left ideal having a countable set of generators, we show that the coderived category of left A-modules is compactly generated by the bounded derived category of finitely presented left A-modules (reproducing a particular case of a recent result of Stovicek with our methods). Furthermore, we present the definition of a dualizing complex of fp-injective modules over a pair of noncommutative coherent rings A and B, and construct an equivalence between the coderived category of A-modules and the contraderived category of B-modules. Finally, we define the notion of a relative dualizing complex of bimodules for a pair of noncommutative ring homomorphisms A \to R and B \to S, and obtain an equivalence between the R/A-semicoderived category of R-modules and the S/B-semicontraderived category of S-modules. For a homomorphism of commutative rings A\to R, we also construct a tensor structure on the R/A-semicoderived category of R-modules. A vision of semi-infinite algebraic geometry is discussed in the introduction.