English

Recognition of Brauer indecomposability for a Scott module

Representation Theory 2022-12-15 v1 Group Theory

Abstract

We give a handy way to have a situation that the kGkG-Scott module with vertex PP remains indecomposable under taking the Brauer construction for any subgroup QQ of PP as k[QCG(Q)]k[Q\,C_G(Q)]-module, where kk is a field of characteristic p>0p>0. The motivation is that the Brauer indecomposability of a pp-permutation bimodule is one of the key steps in order to obtain a splendid stable equivalence of Morita type by making use of the gluing method, that then can possibly lift to a splendid derived equivalence. Further our result explains a hidden reason why the Brauer indecomposability of the Scott module fails in Ishioka's recent examples.

Keywords

Cite

@article{arxiv.2212.07062,
  title  = {Recognition of Brauer indecomposability for a Scott module},
  author = {Shigeo Koshitani and İpek Tuvay},
  journal= {arXiv preprint arXiv:2212.07062},
  year   = {2022}
}

Comments

10 pages. arXiv admin note: text overlap with arXiv:2012.08229

R2 v1 2026-06-28T07:33:49.617Z