Propagation of Electromagnetic Waves in MOG: Gravitational Lensing
  We investigate the solution of Maxwell's equations in curved spacetime within
the framework of Modified Gravity (MOG). We show that besides the null-geodesic
treatment of photons in MOG, using Maxwell's equations and covariant coupling
with the extra vector sector of gravitation in MOG, we can extract the equation
for the propagation of light. We obtain Fermat's potential and calculate the
deflection angle of light during lensing from a point-like star. Our results
show that the deflection angle obtained from the solution of the wave equation
in MOG for the large-scale structures with larger impact parameter of light
rays is proportional to that of General Relativity (GR). For solar mass stars
the deflection angle agrees with the prediction of GR. However, for the compact
structures like the supermassive black hole Sagittarius A* at the centre of the
Milky Way, the prediction for the deflection angle is larger than GR, which can
be tested in future observations.
