English

tCG Torsion Pairs

Category Theory 2018-08-13 v4 Rings and Algebras Representation Theory

Abstract

We investigate conditions for when the tt-structure of Happel-Reiten-Smal{\o} associated to a torsion pair is a compactly generated tt-structure. The concept of a ttCG torsion pair is introduced and for any ring RR, we prove that t=(T,F)\mathbf{t}=(\mathcal{T},\mathcal{F}) is a ttCG torsion pair in R-ModR\text{-Mod} if, and only if, there exists, {Tλ}\{T_{\lambda}\} a set of finitely presented RR-modules in T\mathcal{T}, such that F=Ker(HomR(Tλ,?))\mathcal{F}=\bigcap \text{Ker}({\text{Hom}}_{R}(T_{\lambda},?)). We also show that every ttCG torsion pair is of finite type, and show that the reciprocal is not true. Finally, we give a precise description of the ttCG torsion pairs over Noetherian rings and von Neumman regular rings.

Cite

@article{arxiv.1610.06509,
  title  = {tCG Torsion Pairs},
  author = {Daniel Bravo and Carlos E. Parra},
  journal= {arXiv preprint arXiv:1610.06509},
  year   = {2018}
}

Comments

Made minor corrections to the preliminares and terminology section. Added hyperlinks to the document. To appear in Journal of Algebra and its Applications

R2 v1 2026-06-22T16:26:57.047Z