English

Serre functor and torsion pairs

Representation Theory 2025-10-24 v2

Abstract

Given a torsion pair (T,F)(\mathcal{T},\mathcal{F}) in an abelian category A\mathcal{A} and its Happel-Reiten-Smal{\o} tilt B\mathcal{B}, the equivalence of the realization functor Db(B)Db(A)D^b({\mathcal B})\to D^b({\mathcal A}) is determined by some properties of the torsion pair [9]. We call (T,F)(\mathcal{T},\mathcal{F}) satisfying such a property effaceable. If A\mathcal{A} is an Ext-finite abelian category with Serre duality, we prove that (T,F)(\mathcal{T},\mathcal{F}) is effaceable implies that UT\mathcal{U}_{\mathcal T} is closed under Serre functor. Conversely, when A\mathcal A is the module category of a finite-dimensional hereditary algebra, we prove that the torsion pair (T,F)(\mathcal{T},\mathcal{F}) is effaceable if and only if UT\mathcal{U}_\mathcal{T} is closed under the Serre functor via a recollement of Db(A)D^b({\mathcal A}).

Keywords

Cite

@article{arxiv.2403.07252,
  title  = {Serre functor and torsion pairs},
  author = {Zhe Han and Ping He},
  journal= {arXiv preprint arXiv:2403.07252},
  year   = {2025}
}

Comments

18pages

R2 v1 2026-06-28T15:16:37.409Z