English

Gorenstein projective, injective and flat modules over trivial ring extensions

Rings and Algebras 2023-05-26 v1

Abstract

We introduce the concepts of generalized compatible and cocompatible bimodules in order to characterize Gorenstein projective, injective and flat modules over trivial ring extensions. Let RMR\ltimes M be a trivial extension of a ring RR by an RR-RR-bimodule MM such that MM is a generalized compatible RR-RR-bimodule and Z(R)\textbf{Z}(R) is a generalized compatible RMR\ltimes M-RMR\ltimes M-bimodule. We prove that (X,α)(X,\alpha) is a Gorenstein projective left RMR\ltimes M-module if and only if the sequence MRMRXMαMRXαXM\otimes_R M\otimes_R X\stackrel{M\otimes\alpha}\rightarrow M\otimes_R X\stackrel{\alpha}\rightarrow X is exact and coker(α)(\alpha) is a Gorenstein projective left RR-module. Analogously, we explicitly characterize Gorenstein injective and flat modules over trivial ring extensions. As an application, we describe Gorenstein projective, injective and flat modules over Morita context rings with zero bimodule homomorphisms.

Keywords

Cite

@article{arxiv.2305.15656,
  title  = {Gorenstein projective, injective and flat modules over trivial ring extensions},
  author = {Lixin Mao},
  journal= {arXiv preprint arXiv:2305.15656},
  year   = {2023}
}
R2 v1 2026-06-28T10:45:24.743Z