English

Quotients for sheets of conjugacy classes

Representation Theory 2020-09-22 v1

Abstract

We provide a description of the orbit space of a sheet S for the conjugation action of a complex simple simply connected algebraic group G. This is obtained by means of a bijection between S/G and the quotient of a shifted torus modulo the action of a subgroup of the Weyl group and it is the group analogue of a result due to Borho and Kraft. We also describe the normalisation of the categorical quotient \overline{S}//G for arbitrary simple G and give a necessary and sufficient condition for S//G to be normal in analogy to results of Borho, Kraft and Richardson. The example of G_2 is worked out in detail.

Keywords

Cite

@article{arxiv.1802.00988,
  title  = {Quotients for sheets of conjugacy classes},
  author = {Giovanna Carnovale and Francesco Esposito},
  journal= {arXiv preprint arXiv:1802.00988},
  year   = {2020}
}
R2 v1 2026-06-23T00:09:43.590Z