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arXiv · 2212.07062

Recognition of Brauer indecomposability for a Scott module

Shigeo Koshitani·İpek Tuvay
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Abstract

We give a handy way to have a situation that the $kG$-Scott module with vertex $P$ remains indecomposable under taking the Brauer construction for any subgroup $Q$ of $P$ as $k[Q\,C_G(Q)]$-module, where $k$ is a field of characteristic $p>0$. The motivation is that the Brauer indecomposability of a $p$-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.

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Shigeo Koshitani, İpek Tuvay. 2022-12-14. Recognition of Brauer indecomposability for a Scott module. https://arxiv.org/abs/2212.07062

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