English

Twisted geometric Satake equivalence

Representation Theory 2023-08-25 v3 Algebraic Geometry

Abstract

We generalize the classical Satake equivalence as follows. Let k be an algebraically closed field, set O=k[[t]] and F=k((t)). For an almost simple algebraic group G we classify central extensions of G(F) by the multiplicative group. Any such extension E splits canonically over G(O). Consider the category of G(O)-biinvariant perverse sheaves on E with a given Gm-monodromy . We show that this is a tensor category, which is tensor equivalent to the category of representations of a reductive group. We compute the root datum of this group.

Keywords

Cite

@article{arxiv.0809.3738,
  title  = {Twisted geometric Satake equivalence},
  author = {Michael Finkelberg and Sergey Lysenko},
  journal= {arXiv preprint arXiv:0809.3738},
  year   = {2023}
}

Comments

22 pages, a reference to Lusztig is added. Final version to appear in J. of the Institute of Math. of Jussieu

R2 v1 2026-06-21T11:22:52.205Z