English

Semisimplifications and representations of the General Linear Supergroup

Representation Theory 2025-02-04 v4 Mathematical Physics math.MP

Abstract

We study the semisimplification of the full karoubian subcategory generated by the irreducible finite dimensional representations of the algebraic supergroup GL(mn)GL(m|n) over an algebraically closed field of characteristic zero. This semisimplification is equivalent to the representations of a pro-reductive group HmnH_{m|n}. We show that there is a canonical decomposition HmnGL(m ⁣ ⁣n)×HnnH_{m|n} \cong GL(m\!-\! n) \times H_{n|n}, thereby reducing the determination of HmnH_{m|n} to the equal rank case m ⁣= ⁣nm\! =\! n which was treated in a previous paper.

Keywords

Cite

@article{arxiv.2501.05298,
  title  = {Semisimplifications and representations of the General Linear Supergroup},
  author = {Thorsten Heidersdorf and Rainer Weissauer},
  journal= {arXiv preprint arXiv:2501.05298},
  year   = {2025}
}

Comments

v4: Minor changes in Section 6 (reordering); v3: Added an appendix ("A variant of the $\eta$ functor"); v2: very minor changes (typos etc)

R2 v1 2026-06-28T21:01:24.530Z