Author : Robert Azencott,Edward N. Wilson
Publisher : American Mathematical Soc.
Page : 102 pages
File Size : 55,7 Mb
Release : 1976
Category : Mathematics
ISBN : 9780821821787
Homogeneous Manifolds with Negative Curvature, Part II by Robert Azencott,Edward N. Wilson Pdf
This paper is the second in a series dealing with the structure of the full isometry group I(M) for M a connected, simply connected, homogeneous, Riemannian manifold with non-positive sectional curvature. It is shown that every such manifold determines canonically a conjugacy class of subgroups of I(M) which act simply transitively on M. The class of all simply transitive subgroups of I(M) is identified and it is demonstrated that an arbitrary simply transitive subgroup may be modified slightly to produce a subgroup in the canonical class. The class of all connected Lie groups G for which there exists such a manifold M with G isomorphic to the identity connected component of I(M) is identified by means of a list of structural conditions on the Lie algebra of G. Given an arbitrary connected, simply connected Riemannian manifold M together with a given simply transitive group S of isometries, an algorithm is exhibited to explicitly compute the Lie algebra of I(M) from the transported Riemannian data on S.