## Discontinuous groups and Clifford-Klein forms of pseudo-Riemannian homogeneous manifolds.(English)Zbl 0899.43005

Ørsted, Bent (ed.) et al., Algebraic and analytic methods in representation theory. Proceedings of the main lectures from the European school of group theory, Sønderborg, Denmark, August 15-26, 1994. San Diego, CA: Academic Press. Perspect. Math. 17, 99-165 (1997).
Geometric ideas of various methods together with a number of examples are presented regarding the following fundamental problems: which homogeneous manifolds $$G/H$$ admit properly discontinuous actions of infinite discrete subgroups of $$G$$ and which homogeneous manifolds admit compact Clifford-Klein forms. Some open problems are pointed out.
For the entire collection see [Zbl 0890.00036].
Reviewer: K.Riives (Tartu)

### MSC:

 43A85 Harmonic analysis on homogeneous spaces