English

Birational sheets in reductive groups

Representation Theory 2022-01-17 v2 Group Theory

Abstract

We define the group analogue of birational sheets, a construction performed by Losev for reductive Lie algebras. For G semisimple simply connected, we describe birational sheets in terms of Lusztig-Spaltenstein induction and we prove that they form a partition of G, and that they are unibranch varieties with smooth normalization by means of a local study.

Keywords

Cite

@article{arxiv.2002.11551,
  title  = {Birational sheets in reductive groups},
  author = {Filippo Ambrosio},
  journal= {arXiv preprint arXiv:2002.11551},
  year   = {2022}
}

Comments

25 pages, to appear in Math. Z. A distinction between birational sheets and weakly birational sheets has been introduced. Key modifications/additions: Definition 3.8, Remark 4.4, Subsection 5.1, Remark 5.4, Example 5.5, Remark 5.17, Subsection 5.4, Theorem 6.8