Time emergence by self-measurement in a quantum anisotropic universe

Abstract

We begin this work calculating Halliwell's propagator in the case of a Mixmaster universe with small anisotropy. Afterwards in the context of the Decoherence Model we introduce in our system terms that comprise the self-measurement of the universe of this model by higher multipoles of matter. Analyzing self-measurement with the Restricted Path Integral Formalism we obtain Halliwell's modified propagator and find that a gauge invariant physical time emerges as consequence of this process. The conditions leading to Wheeler-DeWitt dynamics are also obtained. The comparison of our results with those of the isotropic case will enable us to conclude that the number of conditions to be satisfied in order to have Halliwell's regime is in the anisotropic situation bigger than in an isotropic universe. We obtain also in terms of the parameters of the measurement process an expression for the threshold in time beyond which the scale factors of this model are meaningless.