English

Preferred basis, decoherence and a quantum state of the Universe

General Relativity and Quantum Cosmology 2022-04-27 v1 High Energy Physics - Theory Quantum Physics

Abstract

We review a number of issues in foundations of quantum theory and quantum cosmology including, in particular, the problem of the preferred basis in the many-worlds interpretation of quantum mechanics, the relation between this interpretation and the decoherence phenomenon, application of decoherence approach to quantum cosmology, the relation between the many-worlds interpretation and Anthropic Principle along with the notion of quantum-classical duality. We also discuss the concept of fundamentally mixed quantum state of the Universe represented by a special microcanonical density matrix and its dynamical realization in the form of the semiclassically treated path integral over spacetime geometries and quantum matter fields. These issues can be considered as a part of the scientific legacy of H. D. Zeh generously left to us in his two seminal papers published at the beginning of seventies in Foundations of Physics.

Keywords

Cite

@article{arxiv.2006.16812,
  title  = {Preferred basis, decoherence and a quantum state of the Universe},
  author = {Andrei O. Barvinsky and Alexander Yu. Kamenshchik},
  journal= {arXiv preprint arXiv:2006.16812},
  year   = {2022}
}

Comments

25 pages, 3 figures, prepared for the publication in the Springer series "Fundamental Theories of Physics", in the volume, dedicated to the memory of H. D. Zeh. arXiv admin note: text overlap with arXiv:1302.5545