Canonical quantization of cylindrical gravitational waves with two polarizations

The canonical quantization of the minisuperspace model describing cylindrically symmetric gravitational waves with two polarizations is presented. A Fock space-type representation is constructed. It is based on a complete set of quantum observables. Physical expectation values may be calculated in arbitrary excitations of the vacuum. Our approach provides a nonlinear generalization of the quantization of the collinearly polarized Einstein-Rosen gravitational waves.