Wavefunction of a brane-like universe

Within the mini-superspace model, brane-like cosmology means performing the variation with respect to the embedding (Minkowski) time tau before fixing the cosmic (Einstein) time t. The departure from the Einstein limit is par ametrized by the 'energy' conjugate to tau and characterized by a classical ly disconnected embryonic epoch. In contrast with canonical quantum gravity , the wavefunction of the Universe is (a) tau dependent and (b) vanishes at the big bang. Hartle-Hawking and Linde proposals dictate discrete 'energy' levels, whereas the Vilenkin proposal resembles alpha-disintegration.