Interacting universes and the cosmological constant

Abstract

We study some collective phenomena that may happen in a multiverse scenario. First, it is posed an interaction scheme between universes whose evolution is dominated by a cosmological constant. As a result of the interaction, the value of the cosmological constant of one of the universes becomes very close to zero at the expense of an increasing value of the cosmological constant of the partner universe. Second, we found normal modes for a 'chain' of interacting universes. The energy spectrum of the multiverse, being this taken as a collective system, splits into a large number of levels, some of which correspond to a value of the cosmological constant very close to zero. We finally point out that the multiverse may be much more than the mere sum of its parts.Comment: 7 page

Effects of a scalar field on the thermodynamics of interuniversal entanglement

“…Throughout this paper we shall work in units for which = 1 = c. Let us notice that we could consider as well Hamiltonians of interaction between different species of universes adding a more exhaustive phenomenology to the model of the multiverse [8].…”

“…At first sight it would seem that we should just consider one of those regions and disregard the rest of them as physically admissible. However, classical and quantum correlations may appear among different universes of the physical multiverse [7] as well as residual interactions coming from the dimensional reduction of multi-dimensional theories [8]. In that case, other universes should be considered as well in order to describe physical reality [5].…”

“…Furthermore, the existence of quantum correlations in a composite state crucially depends on the representation chosen [18] and it may indeed happen in the multiverse that universes which appear to be independent in a given representation may interact in another representation [8]. Therefore, the boundary conditions of the multiverse will eventually determine the correlations in the composite state of different universes.…”

Conceptual Challenges on the Road to the Multiverse

“…It might be hard to imagine such an indirect effect which could not equally be explained within a single-universe scenario. However, the study of the different schemes of interaction among universes and the development of a toy-model catalogue of observable effects and predictions allows an important progress towards multiverse phenomenology and of the types of effects that could be expected in more detailed scenarios [56][57][58]114,115]. The investigation of these quantum correlations is complicated by the lack of a quantum theory describing our universe, and most current models therefore focus on qualitative approximations to the collective phenomena that can arise in the consideration of a quantum multiverse.…”

The Third Quantization: To Tunnel or Not to Tunnel?

“…The idea that our Universe is not unique but instead resides in a collection of universes, dubbed the multiverse, has appeared several times in cosmology and within vastly different contexts, e.g., in Everett's many worlds interpretation [1], in chaotic inflation [2,3], in the string theory landscape [4], in the ekpyrotic scenario [5,6], and many others [7][8][9][10][11][12][13][14][15]. While there is no unique precise interpretation of the term "multiverse" [9], a transversal idea is the possibility that different universes interact with each other via quantum effects.…”