Conditional Symmetries , the True Degree of Freedom and G . C . T . Invariant Wave functions for the general Bianchi Type II Vacuum Cosmology

The quantization of the most general Bianchi Type II geometry –with all six scale factors, as well as the lapse function and the shift vector, present– is considered. In an earlier work, a first reduction of the initial 6-dimensional configuration space, to a 4-dimensional one, has been achieved by the usage of the information furnished by the quantum form of the linear constraints. Further reduction of the space in which the wave function –obeying the Wheeler-DeWitt equation– lives, is accomplished by unrevealling the extra symmetries of the Hamiltonian. These symmetries appear in the form of –linear in momenta– first integrals of motion. Most of these symmetries, correspond to G.C.T.s through the action of the automorphism group. Thus, a G.C.T. invariant wave function is found, which depends on the only true degree of freedom, i.e. the unique curvature invariant, characterizing the hypersurfaces t = const.