Orateur
Description
The wavefunction of the universe is a solution of the Wheeler–DeWitt equation obtained through the canonical quantization of the Hamiltonian. Different ways of ordering the operators in this Hamiltonian then lead to an ambiguity in the equation. From the path-integral perspective, the wavefunction is also ambiguous, due to the multitude of possible choices for the path-integral measure. We have shown how to completely resolve these ambiguities in simplified cases, where the universe is assumed to be closed and homogeneous. Once the correct expression of the wavefunction is established, we demonstrate how the notion of time in the classical trajectory emerges from the wavefunction, even though the latter does not involve the notion of time in any way.
