ABSTRACT |
We construct a closed string field theory in the proper-time gauge which is the closed analog of the deformed cubic open string field theory and define the general closed string scattering amplitudes. Taking the zero-slope limit, we explicitly evaluate the three-graviton scattering amplitudes and the four-graviton scattering amplitudes. They are shown to reduce to the graviton scattering amplitudes of the Einstein gravity. Given that the four-closed-string interaction is generated perturbatively by the three-closed-string interaction, the quantum theory of gravity may be described consistently as a low energy limit of the closed string field theory which contains a cubic closed string interaction only. |