  The conformal cosmological model presented by Mannheim predicts a negative
value for the effective gravitational constant, G. It also involves a scalar
field, S, which is treated classically. In this paper we point out that a
classical treatment of S is inappropriate, because the Hamiltonian is
non-Hermitean, and the theory must be developed in the way pioneered by Bender
and others. When this is done, we arrive at a Hamiltonian with an energy
spectrum that is bounded below, and also a G that is positive. The resulting
theory closely resembles the conventional cosmology based on Einstein
relativity.

General Relativity and Quantum Cosmology