 
Summary: Transformation Groups, Vol. ?, No. ?, ??, pp. 1?? c
#Birkh˜auser Boston (??)
PARTITIONS OF THE WONDERFUL GROUP
COMPACTIFICATION
JIANGHUA LU #
Department of Mathematics
The University of Hong Kong
Pokfulam Road, Hong Kong
jhlu@maths.hku.hk
MILEN YAKIMOV ##
Department of Mathematics
University of California
Santa Barbara, CA 93106, U.S.A.
yakimov@math.ucsb.edu
Abstract. We define and study a family of partitions of the wonderful compactification G of
a semisimple algebraic group G of adjoint type. The partitions are obtained from subgroups
of G × G associated to triples (A 1 , A 2 , a), where A 1 and A 2 are subgraphs of the Dynkin
graph # of G and a: A 1 # A 2 is an isomorphism. The partitions of G of Springer and Lusztig
correspond respectively to the triples (#, #, id) and (#, #, id).
Introduction
