A broken-symmetry theory of gravity

Quantum effects at the beginning of the universe suggest the variability of the cosmical constant and the effective gravitational constant. These variations may be incorporated into the theory of gravity in a natural way by proposing a longrange complex scalar field similar to the massless Higgs scalar field. On this basis a broken-symmetry theory of gravity has been proposed. The WKB expansion of the complex scalar field helps us to relate the effective gravitational constant to the usual gravitational constant. The proposed theory of gravity has been applied to a homogeneous and isotropic cosmological model to study the quantum effects near the beginning of the universe.