English

$\tau$-Tilting finiteness of group algebras over generalized symmetric groups

Representation Theory 2024-05-20 v1 Group Theory Rings and Algebras

Abstract

In this paper, we show that weakly symmetric τ\tau-tilting finite algebras have positive definite Cartan matrices, which implies that we can prove τ\tau-tilting infiniteness of weakly symmetric algebras by calculating their Cartan matrices. Similarly, we obtain the condition on Cartan matrices that selfinjective algebras are τ\tau-tilting infinite. By applying this result, we show that a group algebra of (Z/plZ)nH(\mathbb{Z}/p^l\mathbb{Z})^n\rtimes H is τ\tau-tilting infinite when plnp^l\geq n and #IBrHmin{p,3}\#\mathrm{IBr}\,H\geq\min\{p,3\}, where p>0p>0 is the characteristic of the ground field, HH is a subgroup of the symmetric group Sn\mathfrak{S}_n of degree nn, the action of HH permutes the entries of (Z/plZ)n(\mathbb{Z}/p^l\mathbb{Z})^n, and IBrH\mathrm{IBr}\,H denotes the set of irreducible pp-Brauer characters of HH. Moreover, we show that under the assumption that plnp^l\geq n and HH is a pp'-subgroup of Sn\mathfrak{S}_n, τ\tau-tilting finiteness of a group algebra of a group (Z/plZ)nH(\mathbb{Z}/p^l\mathbb{Z})^n\rtimes H is determined by its pp-hyperfocal subgroup.

Keywords

Cite

@article{arxiv.2405.10726,
  title  = {$\tau$-Tilting finiteness of group algebras over generalized symmetric groups},
  author = {Naoya Hiramae},
  journal= {arXiv preprint arXiv:2405.10726},
  year   = {2024}
}

Comments

15 pages. arXiv admin note: text overlap with arXiv:2405.10021