Combinatorial geometry and actions of compact Lie groups

Ergodic Actions of Semisimple Lie Groups on Compact Principal Bundles

Let G = SL(n, R) (or, more generally, let G be a connected, noncompact, simple Lie group). For any compact Lie group K, it is easy to find a compact manifold M , such that there is a volume-preserving, connection-preserving, ergodic action of G on some smooth, principal K-bundle P over M. Can M can be chosen independent of K? We show that if M = H / A is a homogeneous space, and the action of G...

Differentiable Actions of Compact Abelian Lie Groups on S»

Compact Lie Groups

The first half of the paper presents the basic definitions and results necessary for investigating Lie groups. The primary examples come from the matrix groups. The second half deals with representation theory of groups, particularly compact groups. The end result is the Peter-Weyl theorem.

Desingularizing Compact Lie Group Actions

This note surveys the well-known structure of G-manifolds and summarizes parts of two papers that have not yet appeared: [4], joint with J. Brüning and F. W. Kamber, and [8], joint with I. Prokhorenkov. In particular, from a given manifold on which a compact Lie group acts smoothly, we construct a sequence of manifolds on which the same Lie group acts, but with fewer levels of singular strata. ...

Lie group actions on compact

Let G be a homotopically trivial and effective compact Lie group action on a compact manifold N of nonpositive curvature. Under certain assumptions on N we prove that if G has dimension equal to rank of Center π1(N), then G must be connected. Furthermore, if on N there exists a point having negative definite Ricci tensor, then we show that G is the trivial group.