English

A height-zero type result for blocks of solvable groups

Group Theory 2026-03-02 v1 Representation Theory

Abstract

Let BB be a pp-block of a finite group GG with defect group DD. The more difficult direction of the recently proven height zero conjecture says that DD is abelian if every character in Irr(B)(B) has height zero. We consider a smaller set than Irr(B)(B). In particular, if φIBrp(B)\varphi \in {\rm IBr}_p(B), we let Irr(φ)(\varphi) be the set of characters χIrr(G)\chi \in {\rm Irr}(G) such that φ\varphi is a constituent of χo\chi^o. Now suppose GG is solvable and φ\varphi is a height zero Brauer character in some block BB of GG with defect group DD. Here we show that if every character in Irr(φ)(\varphi) has height zero, then the defect group DD of the block containing φ\varphi is abelian for p5p \geq 5 and almost abelian for p=2p = 2 or 33. This has a nice consequence for primitive characters of pp-complements in solvable groups.

Keywords

Cite

@article{arxiv.2602.24128,
  title  = {A height-zero type result for blocks of solvable groups},
  author = {James P. Cossey},
  journal= {arXiv preprint arXiv:2602.24128},
  year   = {2026}
}
R2 v1 2026-07-01T10:55:47.371Z