English

Deconstructible abstract elementary classes of modules and categoricity

Representation Theory 2024-10-01 v2 Logic

Abstract

We prove a version of Shelah's Categoricity Conjecture for arbitrary deconstructible classes of modules. Moreover, we show that if A\mathcal{A} is a deconstructible class of modules that fits in an abstract elementary class (A,)(\mathcal{A},\preceq) such that (1) A\mathcal{A} is closed under direct summands and (2) \preceq refines direct summands, then A\mathcal{A} is closed under arbitrary direct limits. In an Appendix, we prove that the assumption (2) is not needed in some models of ZFC.

Keywords

Cite

@article{arxiv.2312.02623,
  title  = {Deconstructible abstract elementary classes of modules and categoricity},
  author = {Jan Šaroch and Jan Trlifaj},
  journal= {arXiv preprint arXiv:2312.02623},
  year   = {2024}
}

Comments

11 pages; Appendix added

R2 v1 2026-06-28T13:41:27.289Z