  The temporal evolution of quantum statistical properties of an interacting
atom-radiation field system in the presence of a classical homogeneous
gravitational field is investigated within the framework of the Jaynes-Cummings
model. To analyse the dynamical evolution of the atom-radiation system a
quantum treatment of the internal and external dynamics of the atom is
presented based on an alternative su(2) dynamical algebraic structure. By
solving the Schr\"{o}dinger equation in the interaction picture, the evolving
state of the system is found by which the influence of the gravitational field
on the dynamical behavior of the atom-radiation system is explored. Assuming
that initially the radiation field is prepared in a coherent state and the
two-level atom is in a coherent superposition of the excited and ground states,
the influence of gravity on the collapses and revivals of the atomic population
inversion, atomic dipole squeezing, atomic momentum diffusion, photon counting
statistics and quadrature squeezing of the radiation field is studied.
