Quantum Cosmology with Third Quantisation

We reviewed the canonical quantisation of geometry spacetime in cases a simply and non-simply connected manifold. In former, we analysed information contained solutions Wheeler–DeWitt equation showed their interpretation terms customary boundary conditions that are typically imposed on semiclassical wave functions. particular, three different paradigms for quantum creation homogeneous isotropic universe. For manifold, best framework is third formalism, which function universe seen as field propagates space Riemannian 3-geometries, turns out to be isomorphic (part a) 1 + 5 Minkowski spacetime. Thus, follows formalism theory. A general review given, universes analysed, including initial expansion appearance matter after inflation. These features presented more detail case The main conclusion both most natural way should created entangled universe–antiuniverse pairs.