Low-Energy Theorem for Graviton Scattering

A low-energy theorem for the scattering of gravitons from spin-0 particles is derived. We use the dispersion-theoretic method, recently utilized by Abarbanel and Goldberger to derive low-energy theorems for the Compton scattering of photons, to write unsubtracted dispersion relations for physical helicity amplitudes. The scattering amplitude at fixed angle is shown to be given by the Born approximation up to fourth-order terms in the graviton energy.