  The Hamiltonian approach to General Relativity is developed similarly to the
Wheeler-DeWitt Hamiltonian cosmology, where the cosmological scale factor is
treated as a time-like dynamic variable and its canonical momentum is
considered as an evolution generator in the field space of events with the
postulate about a physical vacuum as a state with the minimal eigenvalue of
this generator.
  The cosmological scale factor is extracted from the Hamiltonian General
Relativity without double counting of the spatial metric determinant in
contrast to the standard cosmological perturbation theory. The Friedmann-like
equations in the exact theory are derived. A new version of cosmological
perturbation theory keeps the form of the Newton interactions in an early
Universe. We show how the considered Hamiltonian approach to GR can solve the
topical problems of modern cosmology and quantum theory of gravitation.
cosmology and quantum theory of gravitation.
