English

The Green correspondence for SL(2,p)

Representation Theory 2025-05-16 v3

Abstract

Let p>2{p > 2} be an odd prime and G=SL2(Fp){G = SL_2(\mathbb{F}_p)}. Denote the subgroup of upper triangular matrices as BB. Finally, let F{\mathbb{F}} be an algebraically closed field of characteristic p{p}. The Green correspondence gives a bijection between the non-projective indecomposable F[G]{\mathbb{F}[G]} modules and non-projective indecomposable F[B]{\mathbb{F}[B]} modules, realised by restriction and induction. In this paper, we start by recalling a suitable description of the non-projective indecomposable modules for these group algebras. Next, we explicitly describe the Green correspondence bijection by pinpointing the modules' position on the Stable Auslanden-Reiten quivers. Finally, we obtain two corollaries in terms of these descriptions: formulae for lifting the F[B]{\mathbb{F}[B]} module decomposition of an F[G]{\mathbb{F}[G]} module, and a complete description of IndBG{\text{Ind}_B^G} and ResBG{\text{Res}^G_B}.

Keywords

Cite

@article{arxiv.2503.07581,
  title  = {The Green correspondence for SL(2,p)},
  author = {Denver-James Logan Marchment},
  journal= {arXiv preprint arXiv:2503.07581},
  year   = {2025}
}
R2 v1 2026-06-28T22:14:27.720Z