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Perfect quantum cosmological bounce

Gielen, Steffen; Turok, Neil


Steffen Gielen

Neil Turok


We study quantum cosmology with conformal matter comprising a perfect radiation fluid and a number of conformally coupled scalar fields. Focusing initially on the collective coordinates (minisuperspace) associated with homogeneous, isotropic backgrounds, we are able to perform the quantum gravity path integral exactly. The evolution describes a “perfect bounce”, in which the Universe passes smoothly through the singularity. We extend the analysis to spatially flat, anisotropic universes, treated exactly, and to generic inhomogeneous, anisotropic perturbations treated at linear and nonlinear order. This picture provides a natural, unitary description of quantum mechanical evolution across a cosmological bounce. We provide evidence for a semiclassical description in which all fields pass “around” the cosmological singularity along complex classical paths.


Gielen, S., & Turok, N. (2016). Perfect quantum cosmological bounce. Physical Review Letters, 117(2), Article 021301.

Journal Article Type Article
Acceptance Date Mar 16, 2016
Online Publication Date Jul 6, 2016
Publication Date Jul 8, 2016
Deposit Date Oct 23, 2018
Publicly Available Date Oct 23, 2018
Journal Physical Review Letters
Print ISSN 0031-9007
Electronic ISSN 1079-7114
Publisher American Physical Society
Peer Reviewed Peer Reviewed
Volume 117
Issue 2
Article Number 021301
Public URL
Publisher URL


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