Wavefunction of the universe: Reparametrization invariance and field redefinitions of the minisuperspace path integral

Hervé Partouche, Nicolaos Toumbas, Balthazar de Vaulchier

We consider the Hartle-Hawking wavefunction of the universe defined as a Euclidean path integral that satisfies the "no-boundary proposal." We focus on the simplest minisuperspace…