Partitions of the wonderful group compactification
Abstract
Description
We define and study a family of partitions of the wonderful compactification \bar{G} of a semi-simple algebraic group G of adjoint type. The partitions are obtained from subgroups of G \times G associated to triples (A_1, A_2, a), where A_1 and A_2 are subgraphs of the Dynkin graph Γof G and a : A_1 \to A_2 is an isomorphism. The partitions of \bar{G} of Springer and Lusztig correspond respectively to the triples (\emptyset, \emptyset, \id) and (Γ, Γ, \id).
24 pages, AMS Latex, minor revisions in v2
24 pages, AMS Latex, minor revisions in v2