Type: Article
Publication Date: 2003-04-01
Citations: 13
DOI: https://doi.org/10.2969/jmsj/1191419121
We use cohomological group theory and properties of L2-Betti numbers to determine the solvable groups with presentations of deficiency 1, to give a new proof of the "Tits alternative" for subgroups of Haken 3-manifold groups, and to study the fundamental groups of closed 4-manifolds with Euler characteristic 0 and, in particular, 2-knot groups.