Prediction of R + R2 gravity for the deflection of a photon passing close to the Sun

Abstract

The cross-section for the scattering of a photon by the Sun's gravitational field, treated as an external field, is computed in the framework of R + R2 gravity. Using this result, we found that for a photon just grazing the Sun's surface the deflection is 1.75″, which is exactly the same as that given by Einstein's theory. An explanation for this pseudo-paradox is provided.