thesis Compact Lie group actions on contact manifolds Klaus Niederkrüger http://nbn-resolving.de/urn:nbn:de:hbz:38-15014 Ph.D. thesis, Köln 2005 2005 none.jpg The first part of the thesis contains an exposition of S1-actions on 3-manifolds, including the classification of 3-dimensional contact S1-manifolds. The known classification results of 4-dimensional symplectic SO(3)- and SU(2)-manifolds are reproved, before the main result, the classification of 5-dimensional contact SO(3)-manifolds is worked out.