English

Transfer of R-groups between p-adic inner forms of SL_n

Representation Theory 2012-11-27 v2

Abstract

We study the Knapp-Stein RR--groups for inner forms of the split group SLn(F),SL_n(F), with FF a pp--adic field of characteristic zero. Thus, we consider the groups SLm(D),SL_m(D), with DD a central division algebra over FF of dimension d2,d^2, and m=n/d.m=n/d. We use the generalized Jacquet-Langlands correspondence and results of the first named author to describe the zeros of Plancherel measures. Combined with a study of the behavior of the stabilizer of representations by elements of the Weyl group we are able to determine the Knapp-Stein RR--groups in terms of those for SLn(F).SL_n(F). We show the RR--group for the inner form embeds as a subgroup of the RR--group for the split form, and we characterize the quotient. We are further able to show the Knapp-Stein RR--group is isomorphic to the Arthur, or Endoscopic RR--group as predicted by Arthur. Finally, we give some results on multiplicities and actions of Weyl groups on LL--packets.

Keywords

Cite

@article{arxiv.1211.5054,
  title  = {Transfer of R-groups between p-adic inner forms of SL_n},
  author = {Kwangho Choiy and David Goldberg},
  journal= {arXiv preprint arXiv:1211.5054},
  year   = {2012}
}