English

A characterization of IE-closed subcategories via canonical twin support $\tau$-tilting modules

Representation Theory 2026-04-03 v2

Abstract

Enomoto and Sakai classified IE-closed subcategories over hereditary algebras via twin rigid modules. However, this classification inherently relies on the vanishing of second extension spaces, thus failing for arbitrary finite-dimensional algebras. In this paper, we generalize their classification to arbitrary finite-dimensional algebras by introducing the notions of canonical twin support τ\tau-tilting modules and canonical Ext-pairs. By utilizing functorially finite torsion pairs, we provide a homological characterization of these modules. Furthermore, we establish explicit bijections up to isomorphism among functorially finite IE-closed subcategories, canonical twin support τ\tau-tilting modules, and canonical Ext-pairs. Finally, we provide a constructive algorithm to canonicalize any given twin support τ\tau-tilting module.

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Cite

@article{arxiv.2603.13006,
  title  = {A characterization of IE-closed subcategories via canonical twin support $\tau$-tilting modules},
  author = {Hanpeng Gao and Dajun Liu and Yu-Zhe Liu},
  journal= {arXiv preprint arXiv:2603.13006},
  year   = {2026}
}

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