3-MANIFOLDS FOR RELATIVISTS

In canonical quantum gravity certain topological properties of 3-manif olds are of interest. This article gives an account of those propertie s which have so far received sufficient attention, especially those co ncerning the diffeomorphism groups of 3-manifolds. We give a summary o f these properties and list some old and new results concerning them. The appendix contains a discussion of the group of large diffeomorphis ms of the 1-handle 3-manifold.