English

2-Auslander algebras associated with reduced words in Coxeter groups

Representation Theory 2012-10-30 v2 Rings and Algebras

Abstract

In this paper we investigate the endomorphism algebras of standard cluster tilting objects in the stably 2-Calabi-Yau categories \SubΛw\Sub{\Lambda_w} with elements ww in Coxeter groups in \cite{BIRSc}. They are examples of the 2-Auslander algebras introduced in \cite{I1}. Generalizing work in \cite{GLS1} we show that they are quasihereditary, even strongly quasihereditary in the sense of \cite{R}. We also describe the cluster tilting object giving rise to the Ringel dual, and prove that there is a duality between \SubΛw\Sub{\Lambda_w} and the category F(Δ)\mathcal{F}(\Delta) of good modules over the quasihereditary algebra. When w=uvw = uv is a reduced word, we show that the 2-Calabi-Yau triangulated category \SubΛv\underline{\Sub}\Lambda_v is equivalent to a specific subfactor category of \SubΛw.\underline{\Sub}\Lambda_w. This is applied to show that a standard cluster tilting object MM in \SubΛw\Sub{\Lambda_w} and the cluster tilting object ΛwΩM\Lambda_w\oplus\Omega{M} lie in the same component in the cluster tilting graph.

Keywords

Cite

@article{arxiv.1002.3247,
  title  = {2-Auslander algebras associated with reduced words in Coxeter groups},
  author = {Osamu Iyama and Idun Reiten},
  journal= {arXiv preprint arXiv:1002.3247},
  year   = {2012}
}

Comments

14 pages, corrected typos, improved presentation

R2 v1 2026-06-21T14:47:52.274Z