Seminarium Teorii Względności i Grawitacji

I will formulate and study a quantum model of a perturbed Friedmann-Lemaitre-Robertson-Walker universe beyond the conventional Born-Oppenheimer factorization, that is, without restricting the wave function of the universe to the product of the background and perturbation wave functions. I will show that the quantum dynamics generically does not preserve the product form of the wave function that evolves into a more general entangled state. Upon expanding this state in a suitable basis and setting Gaussian initial conditions for the perturbations, I find that each of these wave functions becomes associated to a non-Gaussian probability distribution for the perturbation mode amplitude.