Vacuum fluctuations in an ancestor vacuum: A possible dark energy candidate
Abstract
We consider an open universe created by bubble nucleation, and study possible effects of an "ancestor vacuum" (de Sitter space in which bubble nucleation occurred) on the present universe. We compute vacuum expectation values of energy-momentum tensor for a minimally coupled scalar field, carefully taking into account the effect of the ancestor vacuum by the Euclidean prescription. In the study of the time evolution, an important role is played by the so-called supercurvature mode, which is non-normalizable on a spatial slice of open universe and decays in time most slowly. We point out that vacuum energy of a quantum field can be regarded as dark energy if mass of the field is of order the present Hubble parameter or smaller. We obtain preliminary results for the dark energy equation of state w(z) as a function of the redshift.
Keywords
Cite
@article{arxiv.1710.09179,
title = {Vacuum fluctuations in an ancestor vacuum: A possible dark energy candidate},
author = {Hajime Aoki and Satoshi Iso and Da-Shin Lee and Yasuhiro Sekino and Chen-Pin Yeh},
journal= {arXiv preprint arXiv:1710.09179},
year = {2018}
}
Comments
46 pages, 4 figures; v2: minor changes, references added; v3: corrected the sign of w_1 in eq. (5.62) following the standard convention, references added