Eur. Phys. J. C (2020) 80: 709
https://doi.org/10.1140/epjc/s10052-020-8305-z

Regular Article - Theoretical Physics

Doubleverse entanglement in third quantized non-minimally coupled varying constants cosmologies

¹ Institute of Physics, University of Szczecin, Wielkopolska 15, 70-451, Szczecin, Poland
² Copernicus Center for Interdisciplinary Studies, Szczepańska 1/5, 31-011, Kraków, Poland
³ Chair of Physics, Maritime University of Szczecin, Wały Chrobrego 1-2, 70-500, Szczecin, Poland

^* e-mail: adam.balcerzak@usz.edu.pl

Received: 23 March 2020
Accepted: 30 July 2020
Published online: 7 August 2020

Abstract

In this paper we consider a third quantized cosmological model with varying speed of light c and varying gravitational constant G both represented by non-minimally coupled scalar fields. The third quantization of such a model leads to a scenario of the doubleverse with the two components being quantum mechanically entangled. We calculate the two parameters describing the entanglement, namely: the energy and the entropy of entanglement where the latter appears to be a proper measure of the entanglement. We consider a possibility that the entanglement can manifests itself as an effective perfect fluid characterized by the time dependent barotropic index , which for some specific case corresponds to the fluid of cosmic strings. It seems that such an entanglement induced effective perfect fluid may generate significant backreaction effect at early times.