English

Cotorsion pairs in categories of quiver representations

Category Theory 2019-09-18 v2 Rings and Algebras

Abstract

We study the category Rep(Q,M)\mathrm{Rep}(Q,\mathcal{M}) of representations of a quiver QQ with values in an abelian category M\mathcal{M}. Under certain assumptions, we show that every cotorsion pair (A,B)(\mathcal{A},\mathcal{B}) in M\mathcal{M} induces two (explicitly described) cotorsion pairs (Φ(A),Rep(Q,B))(\Phi(\mathcal{A}),\mathrm{Rep}(Q,\mathcal{B})) and (Rep(Q,A),Ψ(B))(\mathrm{Rep}(Q,\mathcal{A}),\Psi(\mathcal{B})) in Rep(Q,M)\mathrm{Rep}(Q,\mathcal{M}). This is akin to a result by Gillespie, which asserts that a cotorsion pair (A,B)(\mathcal{A},\mathcal{B}) in M\mathcal{M} induces cotorsion pairs (A~,dgB~)(\widetilde{\mathcal{A}}, \mathrm{dg}\,\widetilde{\mathcal{B}}) and (dgA~,B~)(\mathrm{dg}\,\widetilde{\mathcal{A}}, \widetilde{\mathcal{B}}) in the category Ch(M)\mathrm{Ch}(\mathcal{M}) of chain complexes in M\mathcal{M}. Special cases of our results recover descriptions of the projective and injective objects in Rep(Q,M)\mathrm{Rep}(Q,\mathcal{M}) proved by Enochs, Estrada, and Garcia Rozas.

Keywords

Cite

@article{arxiv.1604.01517,
  title  = {Cotorsion pairs in categories of quiver representations},
  author = {Henrik Holm and Peter Jorgensen},
  journal= {arXiv preprint arXiv:1604.01517},
  year   = {2019}
}

Comments

23 pages. This is the Final Accepted Version which was accepted 13 April 2017 for publication in the Kyoto Journal of Mathematics