  In the present work, an expression for Planck Mass or Planck Energy is
derived by equating the Compton wavelength with the gravitational radius of the
Kerr rotating body. Using the modified photon energy-momentum dispersion
relation, the variation of the photon propagation speed with photon frequency
is derived. It is found that, the photon propagation speed, depends on the
frequency of the photon, the rotation parameter of the Kerr rotating body and
also on the polarization state of the photon. Quantum gravity effect could be
seen from the derived results for the photon propagation speed.
