TYPES IN SL n
TYPES IN SL n
复制标题
SL n 中的类型
DOI:
10.1112/s002461150201359x
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发表时间:
2002
影响因子:
1.8
通讯作者:
Alan Roche
中科院分区:
文献类型:
--
作者:
David Goldberg;Alan Roche
Let F be a non-Archimedean local field and G the group of F-points of a connected reductive algebraic group defined over F. Write RG for the category of smooth complex representations of G. By [1], RG has a canonical decomposition as a product of certain indecomposable subcategories, called components. To clarify the study of RG by the method of restriction to compact open subgroups, Bushnell and Kutzko have introduced the concept of a type for a component. This is a pair J, r with J a compact open subgroup of G and r an irreducible smooth representation of J such that the objects of the given component are precisely the objects of RG that are generated by their r-isotypic vectors. A component that admits a type J, r is equivalent, by [6, 4.3], to the category of right modules over the Hecke algebra HG, r, the convolution algebra of compactly supported r-spherical functions on G.Bushnell and Kutzko's work on GLn F provides a complete set of types for these groups, that is, a type of each component of RG when G GLn F. It also describes the structure of the corresponding Hecke algebras. Here we use a part of this work, along with [5] and the general machinery of [6], to construct certain families of types in SLn F. Our results, in combination with those of [5], yield a complete set of types for these groups. We will address the structure of the corresponding Hecke algebras in a sequel. To discuss the contents of the paper more closely, we now assume some familiarity with the notation and terminology of [6]. In particular, if L is a Levi subgroup of G and j is an irreducible supercuspidal representation of L, we write L, j G for the G-inertial class determined by j and BG for the set of all such classes (as in [6, § 1]). Let G GLn F and GH SLn F. In general, if H is a subgroup of G, we write Hh H∩ GH. Fix a Levi subgroup L of G. In §§ 1 and 2 we construct, for LTG, a complete set of supercuspidal LH-types (that is, a type for each element of BLh) of the form LH, jH LH). The construction parallels, and relies crucially upon, the case LG which is studied in [5]. There Bushnell and Kutzko define the family of maximal simple types in GH in terms of the maximal simple types in G of [3, 6.2]. They then prove that the GH-objects have analogous properties to their G-namesakes. More precisely, they show that each irreducible supercuspidal representation pH of GH contains a maximal simple type in GH, which is unique up to GH-conjugation, and that each such simple type is a GH, pH Gh-type.