English

$\tau$-exceptional sequences

Representation Theory 2021-06-04 v3

Abstract

We introduce the notions of τ\tau-exceptional and signed τ\tau-exceptional sequences for any finite dimensional algebra. We prove that for a fixed algebra of rank nn, and for any positive integer tnt \leq n, there is a bijection between the set of signed τ\tau-exceptional sequences of length tt, and (basic) ordered support τ\tau-rigid objects with tt indecomposable direct summands. If the algebra is hereditary, our notions coincide with exceptional and signed exceptional sequences. The latter were recently introduced by Igusa and Todorov, who constructed a similar bijection in the hereditary setting.

Keywords

Cite

@article{arxiv.1802.01169,
  title  = {$\tau$-exceptional sequences},
  author = {Aslak Bakke Buan and Bethany Marsh},
  journal= {arXiv preprint arXiv:1802.01169},
  year   = {2021}
}

Comments

28 pages. To appear in the Journal of Algebra

R2 v1 2026-06-23T00:10:18.282Z