  We consider effective action for the Einstein gravity and show that dressed
mean fields are actual variables of the effective action. Kernels of this
effective action expressed in terms of dressed effective fields are constituent
parts of scattering amplitudes for gravitons. Possible applications to the
graviton scattering and black hole formation are discussed at the semiclassical
level. In particular, we consider graviton scattering in four dimensions based
on the Lipatov effective action for quantum gravity, shock waves of particles
moving on the brane in Randall-Sundrum scenario with fifth extra dimension, and
Giddings' estimation of Froissart bound.
