On the Steinberg presentation for Lie-type groups of type C2
✍ Scribed by C. Müller
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 104 KB
- Volume
- 252
- Category
- Article
- ISSN
- 0021-8693
No coin nor oath required. For personal study only.
✦ Synopsis
Let Φ be an irreducible root-system of rank 2 satisfying the crystallographic condition. (That is, Φ is one of types A , B , C , l 2, D , 4, E , 6 8, F 4 or G 2 .) Inspired by the Steinberg presentation of Chevalley groups, recently Timmesfeld considered the following situation (cf. [1-3]):
Let G be an abstract group generated by subgroups A α , α ∈ Φ, satisfying the following hypothesis denoted by (H):
is a rank-one group with unipotent subgroups A α and A -α . (For definition of a rank-one group see Section 2.) Clearly, all Chevalley groups satisfy (H). Hence the question arises which possibilities exist in general for the structure of a group satisfying (H). For the case that in condition (i) equality always holds, Timmesfeld solved this problem in [1]:
1.1. Theorem. Suppose G satisfies (H) with equality holding in condition (i). Then there exists a surjective homomorphism ϕ : G → G, where G is a group of Lie-type B, B an irreducible, spherical Moufang building, which maps the A α ,
📜 SIMILAR VOLUMES
This paper gives a uniform method of constructing generators for matrix representations of finite groups of Lie type with particular emphasis on the exceptional groups. The algorithm constructs matrices for the action of root elements on the lowest dimension representation of an associated Lie algeb
We associate a weighted graph ⌬ G to each finite simple group G of Lie type. ## Ž . We show that, with an explicit list of exceptions, ⌬ G determines G up to Ž . isomorphism, and for these exceptions, ⌬ G nevertheless determines the characteristic of G. This result was motivated by algorithmic c
For each simply connected semisimple algebraic group G defined and split over the prime field ކ , we establish a uniform bound on n above which all of the first p Ž . cohomology groups with values in the simple modules for the finite group G n are Ž . determined by those for the algebraic group G