English

Completeness of the induced cotorsion pairs in functor categories

Representation Theory 2021-09-09 v4 K-Theory and Homology

Abstract

This paper focuses on a question raised by Holm and J{\o}rgensen, who asked if the induced cotorsion pairs (Φ(X),Φ(X))(\Phi({\sf X}),\Phi({\sf X})^{\perp}) and (Ψ(Y),Ψ(Y))(^{\perp}\Psi({\sf Y}),\Psi({\sf Y})) in Rep(Q,A)\mathrm{Rep}(Q,{\sf{A}}) -- the category of all A\sf{A}-valued representations of a quiver QQ -- are complete whenever (X,Y)(\sf X,\sf Y) is a complete cotorsion pair in an abelian category A\sf{A} satisfying some mild conditions. Recently, Odaba\c{s}{\i} gave an affirmative answer if the quiver QQ is rooted and the cotorsion pair (X,Y)(\sf X,\sf Y) is further hereditary. In this paper, we improve Odaba\c{s}{\i}'s work by removing the hereditary assumption on the cotorsion pair. As an application, we show under certain mild conditions that if a subcategory L\sf L, which is not necessarily closed under direct summands, of A\sf A is special precovering (resp., preenveloping), then Φ(L)\Phi(\sf L) (resp., Ψ(L)\Psi(\sf L)) is special precovering (resp., preenveloping) in Rep(Q,A)\mathrm{Rep}(Q,{\sf{A}}).

Keywords

Cite

@article{arxiv.2102.05826,
  title  = {Completeness of the induced cotorsion pairs in functor categories},
  author = {Zhenxing Di and Liping Li and Li Liang and Fei Xu},
  journal= {arXiv preprint arXiv:2102.05826},
  year   = {2021}
}