Torsion and the probability of inflation
OA Location
Author(s)
Albertini, Emma
Alexander, Stephon
Herczeg, Gabriel
Magueijo, João
Type
Journal Article
Abstract
We revisit the problem of the "probability of inflation" from the point of view of the Einstein-Cartan theory, where torsion can be present off-shell even in the absence of spinorial currents. An informal estimate suggests that the barrier for tunneling from "nothing" into a classical universe becomes thinner and lower, should torsion be present, even if only off-shell. We perform a detailed calculation that supports this informal estimate for the case of torsion eigenstates. Finally, we impose a quantum mechanical analog of the zero-torsion condition by restricting to states for which the expectation value of the torsion vanishes. An explicit family of such states is obtained by building wave-packets from linear superpositions of torsion eigenstates with Gaussian weights centered around zero torsion. The tunneling probability for these wave packets is maximized when the variance of the torsion goes to zero. Hence, by considering these wave-packets as the physical states, we recover a sensible model of quantum cosmology that incorporates quantum fluctuations in the torsion, despite the apparently unacceptable conclusions one draws from naïvely considering the tunneling probabilities for the torsion eigenstates.
Date Issued
2022-11-16
Date Acceptance
2022-11-02
Citation
Journal of Cosmology and Astroparticle Physics, 2022, 2022 (11), pp.1-14
ISSN
1475-7516
Publisher
IOP Publishing
Start Page
1
End Page
14
Journal / Book Title
Journal of Cosmology and Astroparticle Physics
Volume
2022
Issue
11
Copyright Statement
© 2022 IOP Publishing Ltd and Sissa Medialab
Sponsor
Science and Technology Facilities Council (STFC)
Identifier
https://iopscience.iop.org/article/10.1088/1475-7516/2022/11/036
Grant Number
ST/T000791/1
Subjects
Nuclear & Particles Physics
0201 Astronomical and Space Sciences
0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics
Publication Status
Published
Date Publish Online
2022-11-16