The quantum universe

Abstract

In this paper we review how a background independent non-perturbative regularization of quantum gravity, denoted causal dynamical triangulation (CDT), in the infrared leads to the standard minisuperspace effective action. We show how it is possible to study in detail the quantum fluctuations around the classical solution to the minisuperspace action and outline how one in principle might be able to study the quantum gravity theory in the sub-Planckian regime.