  The Gravitoelectromagnetism (GEM) theory is considered in a lagrangian
formulation using the Weyl tensor components. A perturbative approach to
calculate processes at zero temperature has been used. Here the GEM at finite
temperature is analyzed using Thermo Field Dynamics, real time finite
temperature quantum field theory. Transition amplitudes involving gravitons,
fermions and photons are calculated for various processes. These amplitudes are
likely of interest in astrophysics.
