Functorial equivalence classes of 2-blocks of tame representation type

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Authors: Robert Boltje, Serge Bouc, Denız Yılmaz
Cited by: 0

Abstract

For any block of a finite group over an algebraically closed field of characteristic $2$ which has dihedral, semidihedral, or generalized quaternion defect groups, we determine explicitly the decomposition of the associated diagonal $p$-permutation functor over an algebraically closed field $\mathbb{F}$ of characteristic $0$ into a direct sum of simple functors. As a consequence we see that two blocks with dihedral, semidihedral, or generalized quaternion defect groups are functorially equivalent over $\mathbb{F}$ if and only if their fusion systems are isomorphic. It is an open question if two blocks (with arbitrary defect groups) that are functorially equivalent over $\mathbb{F}$ must have isomorphic fusion systems. The converse is wrong in general.

Fields of Study & Subjects

Finite Group Theory Research Homotopy and Cohomology in Algebraic Topology Geometric and Algebraic Topology

Publication details

Journal / source
Tunisian Journal of Mathematics
Volume
8
Issue
4
Pages
705–721
Publication date
10 September 2026
Language
EN