English

Comparison of compact induction with parabolic induction

Representation Theory 2011-12-01 v1 Number Theory

Abstract

Let FF be any non archimedean locally compact field of residual characteristic pp, let GG be any reductive connected FF-group and let KK be any special parahoric subgroup of G(F)G(F). We choose a parabolic FF-subgroup PP of GG with Levi decomposition P=MNP=MN in good position with respect to KK. Let CC be an algebraically closed field of characteristic pp. We choose an irreducible smooth CC-representation VV of KK. We investigate the natural intertwiner from the compact induced representation \indKG(F)V\ind_{K}^{G(F)}V to the parabolically induced representation \IndP(F)G(F)(\indM(F)KM(F)VN(F)K)\Ind_{P(F)}^{G(F)}(\ind_{M(F) \cap K}^{M(F)}V_{N(F)\cap K}). Under a regularity condition on VV, we show that the intertwiner becomes an isomorphism after a localisation at a specific Hecke operator. When FF has characteristic 0, GG is FF-split and KK is hyperspecial, the result was essentially proved by Herzig. We define the notion of KK-supersingular irreducible smooth CC-representation of G(F)G(F) which extends Herzig's definition for admissible irreducible representations and we give a list of KK-supersingular irreducible representations which are supercuspidal and conversely a list of supercuspidal representations which are KK-supersingular.

Keywords

Cite

@article{arxiv.1111.7276,
  title  = {Comparison of compact induction with parabolic induction},
  author = {Henniart Guy and Vigneras Marie-France},
  journal= {arXiv preprint arXiv:1111.7276},
  year   = {2011}
}

Comments

28 pages

R2 v1 2026-06-21T19:44:13.830Z