Using Deodhar's decomposition of a double Schubert cell, we study the regular representations of finite groups of Lie type arising in the cohomology of Deligne-Lusztig varieties associated to tori. We deduce that the Deligne-Lusztig restriction of a Gelfand-Graev module is a shifted Gelfand-Graev module.
机构:
Inst Math Jussieu Paris R Gauche IMJ PRG, 4 Pl Jussieu, F-75252 Paris 05, FranceInst Math Jussieu Paris R Gauche IMJ PRG, 4 Pl Jussieu, F-75252 Paris 05, France