English

On Shalika germs

Representation Theory 2016-03-28 v1

Abstract

Let GG be a reductive group over a local field FF satisfying the assumptions of \cite{Deb1}, GregGG_{reg}\subset G the subset of regular elements. Let TGT\subset G be a maximal torus. We write Treg=TGregT_{reg}=T\cap G_{reg}. Let dg,dtdg ,dt be Haar measures on GG and TT. They define an invariant measure dg/dtdg/dt on G/TG/T. Let H\mathcal{H} be the space of complex valued locally constant functions on GG with compact support. For any fH,tTregf\in \mathcal{H} ,t\in T_{reg} we define It(f)=G/Tf(gˉtgˉ1)dg/dtI_t(f)=\int_{G/T}f(\bar gt\bar g^{-1})dg/dt. Let PP be the set of conjugacy classes of unipotent elements in GG. For any ΩP\Omega \in P we fix an invariant measure ω\omega on Ω\Omega. As well known \cite {R} for any fHf\in \mathcal{H} the integral IΩ(f)=ΩfωI_\Omega (f)=\int_\Omega f\omega is absolutely convergent. Shalika \cite{Sh} has shown that there exist functions j~Ω(t),ΩP\tilde{j}_\Omega (t),\Omega \in P on TGregT\cap G_{reg} such that It(f)=ΩPj~Ω(t)IΩ(f)()I_t(f) = \sum_{\Omega \in P} \tilde{j}_\Omega(t) I_\Omega(f)\qquad\qquad (\star) for any fH,tTf\in \mathcal{H} ,t\in T {\it near} to ee where the notion of {\it near} depends on ff. For any positive real number rr one defines an open AdAd-invariant subset GrG_r of GG and a subspace Hr\mathcal{H}_r as in \cite{Deb1}. In this paper I show that for any fHrf\in \mathcal{H}_r the equality ()(\star) is true for all tTregGrt\in T_{reg}\cap G_r.

Keywords

Cite

@article{arxiv.1603.07874,
  title  = {On Shalika germs},
  author = {David Kazhdan},
  journal= {arXiv preprint arXiv:1603.07874},
  year   = {2016}
}

Comments

3 pages

R2 v1 2026-06-22T13:18:36.454Z