On profinite groups with finite abelianizations

Profinite groups with finite p-abelianizations arise in various contexts: group theory, number theory and geometry. Using Ph. Furtwangler's transfer vanishing theorem it will be proved that a finitely generated profinite group 0 with this property satisfies H-1 ((G) over cap, F-p parallel to(G) over cap parallel to) = 0 (Thm. A). As a consequence one finds that a hereditarily just-infinite non-virtually cyclic pro-p group has only one end (Cor. B). Applied to 3-dimensional Poincare duality groups, Theorem A yields a generalization of A. Reznikov's theorem on 3-dimensional co-compact hyperbolic lattices violating W. Thurston's conjecture (Thm. C).