English

Overgroups of elementary groups in polyvector representations

Group Theory 2022-03-28 v1

Abstract

We initiate the study of subgroups HH of the general linear group GL(nm)(R)GL_{\binom{n}{m}}(R) over a commutative ring RR that contain the mm-th exterior power of an elementary group mEn(R)\bigwedge^mE_n(R). Each such group HH corresponds to a uniquely defined level (A0,,Am1)(A_0,\dots,A_{m-1}), where A0,,Am1A_0,\dots,A_{m-1} are ideals of RR with certain relations. In the crucial case of the exterior squares, we state the subgroup lattice to be standard. In other words, for 2En(R)\bigwedge^2E_n(R) all intermediate subgroups HH are parametrized by a single ideal of the ring RR. Moreover, we characterize mGLn(R)\bigwedge^mGL_n(R) as the stabilizer of a system of invariant forms. This result is classically known for algebraically closed fields, here we prove the corresponding group scheme to be smooth over Z\mathbb{Z}. So the last result holds over arbitrary commutative rings.

Keywords

Cite

@article{arxiv.2203.13683,
  title  = {Overgroups of elementary groups in polyvector representations},
  author = {Roman Lubkov},
  journal= {arXiv preprint arXiv:2203.13683},
  year   = {2022}
}
R2 v1 2026-06-24T10:25:59.915Z