The entangled accelerating universe

Using the known result that the nucleation of baby universes in correlated pairs is equivalent to spacetime squeezing, we show in this letter that there exists a T-duality symmetry between two-dimensional warp drives, which are physically expressible as localized de Sitter little universes, and two dimensional Tolman-Hawking and Gidding-Strominger baby universes respectively correlated in pairs, so that the creation of warp drives is also equivalent to spacetime squeezing. Perhaps more importantly, it has been also seen that the nucleation of warp drives entails a violation of the Bell's inequalities, and hence the phenomena of quantum entanglement, complementarity and wave function collapse. These results are generalized to the case of any dynamically accelerating universe filled with dark or phantom energy whose creation is also physically equivalent to spacetime squeezing and to the violation of the Bell's inequalities, so that the universe we are living in should be governed by essential sharp quantum theory laws and must be a quantum entangled system

Quantum cosmology with third quantisation

We reviewed the canonical quantisation of the geometry of the spacetime in the cases of a simply and a non-simply connected manifold. In the former, we analysed the information contained in the solutions of the Wheeler-DeWitt equation and showed their interpretation in terms of the customary boundary conditions that are typically imposed on the semiclassical wave functions. In particular, we reviewed three different paradigms for the quantum creation of a homogeneous and isotropic universe. For the quantisation of a non-simply connected manifold, the best framework is the third quantisation formalism, in which the wave function of the universe is seen as a field that propagates in the space of Riemannian 3-geometries, which turns out to be isomorphic to a (part of a) 1 + 5 Minkowski spacetime. Thus, the quantisation of the wave function follows the customary formalism of a quantum field theory. A general review of the formalism is given, and the creation of the universes is analysed, including their initial expansion and the appearance of matter after inflation. These features are presented in more detail in the case of a homogeneous and isotropic universe. The main conclusion in both cases is that the most natural way in which the universes should be created is in entangled universe-antiuniverse pairs.This work was supported by Comunidad de Madrid (Spain) under the Multiannual Agreement with UC3M in the line of Excellence of University Professors (EPUC3M23), in the context of the 5th. Regional Programme of Research and Technological Innovation (PRICIT)

Inter-Universal Entanglement

Quantum information theory and the multiverse are two of the greatest outcomes of the XX century physics. The consideration of entanglement between the quantum states of two or more universes in a multiverse scenario provides us with a completely new paradigm that opens the door to novel approaches for traditionally unsolved problems in cosmology. More precisely, the problems of the cosmological constant, the arrow of time and the choice of boundary conditions, among others. It also encourages us to adopt new points of view about major philosophical ideas. In this chapter, we shall present the main features that may characterize inter-universal entanglement and it will be addressed the customary problems of cosmology from the new perspective that the quantum multiverse scenario supplies us with. In summary, the appropriate boundary condition that has to be imposed on the quantum state of the whole multiverse allows us to interpret it as made up of entangled pairs of universes. Then, a quantum thermodynamical description of single universes can be given and it can be shown that it may induce observable effects in the energy properties of the Universe. The effects that the boundary condition of the multiverse has on the vacuum energy and the arrow of time of single universes are also studied. As a consequence of inter-universal entanglement, the former might be discriminated from observational data and the latter would favor the growth of cosmic structures that increase the amount of local entropy mainly in the very early phase of the universe. All these characteristics of inter-universal entanglement would eventually impel us to develop the concept of the physical multiverse, one for which the theory could be not only fallible but also indirectly observed.Comment: 36 pages, 7 figures. Chapter written for the book "Open Questions in Cosmology", Edited by: Gonzalo J. Olmo, InTech Publishing, Rijeka, Croatia, (2012), ISBN 978-953-51-0880-1. The properly formatted version can be freely downloaded from the publisher's websit

Pre-inflation from the multiverse: Can it solve the quadrupole problem in the cosmic microwave background?

We analyze a quantized toy model of a universe undergoing eternal inflation using a quantum-field-theoretical formulation of the Wheeler-DeWitt equation. This so-called third quantization method leads to the picture that the eternally inflating universe is converted to a multiverse in which sub-universes are created and exhibit a distinctive phase in their evolution before reaching an asymptotic de Sitter phase. From the perspective of one of these sub-universes, we can thus analyze the pre-inflationary phase that arises naturally. Assuming that our observable universe is represented by one of those sub-universes, we calculate how this pre-inflationary phase influences the power spectrum of the cosmic microwave background (CMB) anisotropies and analyze whether it can explain the observed discrepancy of the power spectrum on large scales, i.e. the quadrupole issue in the CMB. While the answer to this question is negative in the specific model analyzed here, we point out a possible resolution of this issue.Comment: 15 pages, 9 figures. Correction of typos, one figure added. Accepted for publication in European Physical Journal

What if? - Exploring the Multiverse through Euclidean wormholes

We present Euclidean wormhole solutions describing possible bridges within the multiverse. The study is carried out in the framework of the third quantization. The matter content is modelled through a scalar field which supports the existence of a whole collection of universes. The instanton solutions describe Euclidean solutions that connect baby universes with asymptotically de Sitter universes. We compute the tunnelling probability of these processes. Considering the current bounds on the energy scale of inflation and assuming that all the baby universes are nucleated with the same probability, we draw some conclusions about what are the universes more likely to tunnel and therefore undergo a standard inflationary era.Comment: 12 pages, 5 figures. Explanations improved. Version accepted in EPJ