BACK REFLECTION OF SCALAR AND VECTOR WAVES IN GRAVITATIONAL FIELDS

The back reflection of mass-zero scalar or vector waves passing through a gravitational field is calculated. In the Newtonian (equivalence-principle) approximation to Einstein's or Brans and Dicke's gravitational theory, no back reflection occurs. The non-Lorentz part of the spatial metric components (gxx,Âgyy, gzz) produce the back reflection of the waves. For optimum wavelengths, the reflection coefficient of a wave passing a mass M at distance d is of order GMc2d. © 1969 The American Physical Society.