Pro-p-Iwahori Hecke ring and supersingular -representations
Pro-p-Iwahori Hecke ring and supersingular -representations
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DOI:
10.1007/s00208-004-0592-4
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发表时间:
2005-03
影响因子:
1.4
通讯作者:
M. Vigneras
中科院分区:
文献类型:
--
作者:
M. Vigneras
The motivation of this paper is the search for a Langlands correspondence modulop. We show that the pro-p-Iwahori Hecke ring of a split reductivep-adic groupGover a local fieldFof finite residue fieldFqwithqelements, admits an Iwahori-Matsumoto presentation and a BernsteinZ-basis, and we determine its centre. We prove that the ring is finitely generated as a module over its centre. These results are proved in [11] only for the Iwahori Hecke ring. Letpbe the prime number dividingqand letkbe an algebraically closed field of characteristicp. A character from the centre of tokwhich is “as null as possible” will be called null. The simple -modules with a null central character are called supersingular. WhenG=GL(n), we show that each simple -module of dimensionncontaining a character of the affine subring is supersingular, using the minimal expressions of Haines generalized to , and that the number of such modules is equal to the number of irreduciblek-representations of the Weil groupWFof dimensionn(when the action of an uniformizerpFin the Hecke algebra side and of the determinant of a Frobenius FrFin the Galois side are fixed), i.e. the numberNn(q) of unitary irreducible polynomials inFq[X] of degreen. One knows that the converse is true by explicit computations whenn=2 [10], and whenn=3 (Rachel Ollivier).