Deflection of light in the brans-dicke gravitational theory

Abstract

In general relativity there are two ideas about the gravitational "constant" G. That is, G is assumed to be constant in the Einstein gravitational theory and is not to be constant in the scalar-tensor theory developed recently such as the Brans-Dicke gravitational theory. We study such a thing by reviewing the theory of Einstein and Brans-Dicke, and compare them according to Mach``s principle by colligating and readjusting the two theories. And we calculate the deflection of light by the sun as a fundamental test for the validity of the two theories. These calculated values are same in both theories and correspond with experiments, but do still not distinguish the two theories.