Let G be a group, F a field, and A a finite-dimensional central simple algebra over F on which G acts by F-algebra automorphisms. We study the subalgebras and ideals of A which are preserved by the group action. We prove a structure theorem and two classification theorems for invariant subalgebras u
On Multicommutators for Simple Algebraic Groups
โ Scribed by Nikolai Gordeev; Ulf Rehmann
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 158 KB
- Volume
- 245
- Category
- Article
- ISSN
- 0021-8693
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โฆ Synopsis
There are several examples of groups for which any pair of commutators can be written such that both of them have a common entry, and one can look for a similar property for n-tuples of commutators. Here we answer, for simple algebraic groups over any field, the weaker question, under which condition the set of n-tuples of commutators with one common entry is Zariski dense in the set of all n-tuples of commutators. Surprisingly, there is a uniform bound on n in terms of the so-called Coxeter number of G to answer the question positively. An analogue result is proved for Lie algebras of simple and simply connected algebraic groups.
๐ SIMILAR VOLUMES
Let g be a semi-simple complex Lie algebra and g=n -ร h ร n its triangular decomposition. Let U(g), resp. U q (g), be its enveloping algebra, resp. its quantized enveloping algebra. This article gives a quantum approach to the combinatorics of (classical) harmonic elements and Kostant's generalized