CRITICAL EXPONENT OF NEGATIVELY CURVED THREE MANIFOLDS

We prove that for a negatively pinched (-b^2<=K<= -1) topologically tame 3-manifold {M~}/(Gamma), all geometrically infinite ends are simply degenerate. And if the limit set of (Gamma) is the entire boundary sphere at infinity, then the action of (Gamma) on the boundary sphere is ergodic with respect to harmonic measure, and the Poincare series diverges when the critical exponent is 2.