The problem that we are concerned with is the existence and construction of embeddings of a given G-CW complex (G-manifold) in another G-CW complex (G-manifold) having a prescribed homotopy type and a prescribed family of isotropy subgroups.
This paper deals with the two broad questions of how 3-manifold groups imbed in one another and how such imbeddings relate to any corresponding [lowercase Greek]Pi₁-injective maps. In particular, we are interested in 1) determining which 3-manifold groups are no cohopfian, that …
There are two parts to this paper. In the first part, we solve the problem of when a finite regular covering of a closed [italic]n-manifold M is homotopic to an embedding in an [italic]n-plane bundle over M. The results of the first part are used in the second part to obtain res…
