Unitriangularity of decomposition matrices of the unipotent ℓ-blocks for simple adjoint exceptional groups

2024/02/26 by M.P. Roth, Roth, Marie
Mathematics · Computer Science · #Advanced Topics in Algebra #Matrix Theory and Algorithms #Holomorphic and Operator Theory

paper · pdf · doi:10.48550/arxiv.2402.17616

Abstract

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

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