English

Unitriangularity of decomposition matrices of the unipotent ${\ell}$-blocks for simple adjoint exceptional groups

Representation Theory 2024-02-28 v1

Abstract

In 2020, Brunat-Dudas-Taylor showed that the decomposition matrix of unipotent {\ell}-blocks of a nite reductive group in good characteristic has unitriangular shape, under some conditions on the prime {\ell}, in particular {\ell} being good. We extend this result to {\ell} bad by adapting their proof to include the {\ell}-special classes dened by Chaneb.

Keywords

Cite

@article{arxiv.2402.17616,
  title  = {Unitriangularity of decomposition matrices of the unipotent ${\ell}$-blocks for simple adjoint exceptional groups},
  author = {Marie Roth},
  journal= {arXiv preprint arXiv:2402.17616},
  year   = {2024}
}