The DOI matches its Crossref record; 2 of the 2 references it cites were found in a registry or an index.
Inconsistencies of the New No-Boundary Proposal
Abstract
In previous works, we have demonstrated that the path integral for real, Lorentzian four-geometries in Einstein gravity yields sensible results in well-understood physical situations, but leads to uncontrolled fluctuations when the “no boundary” condition proposed by Hartle and Hawking is imposed. In order to circumvent our result, new definitions for the gravitational path integral have been sought, involving specific choices for a class of complex four-geometries to be included. In their latest proposal, Diaz Dorronsoro et al. advocate for integrating the lapse over a complex circular contour enclosing the origin. In this note, we show that, like their earlier proposal, this leads to mathematical and physical inconsistencies and thus cannot be regarded as a basis for quantum cosmology. We also comment on Vilenkin and Yamada’s recent modification of the “tunneling" proposal, made in order to avoid the same problems. We show that it leads to the breakdown of perturbation theory in a strong coupling regime.
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Saharian and Mkhitaryan carried out the corresponding Casimir calculation for a power-law expanding universe, with a(t) ∝ t^p, and found that it agrees with the static calculation in the limit of small a.
“Saharian and Mkhitaryan [40] carried out the corresponding calculation for a power-law expanding universe, with a(t) ∝ t p , and found, as one would expect, that it agrees with the static calculation in the limit of small a.”
From On Quantum Creation of a Toroidal Universe (2026) · cites this paper as [40]
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Hartle, J. B., & Hawking, S. W. (1983) · Physical Review D · doi:10.1103/physrevd.28.2960 · Cited by 3,027
Creation of universes from nothing
Vilenkin, A. (1982) · Physics Letters B · doi:10.1016/0370-2693(82)90866-8 · Cited by 841
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Research works printed but not linked: 13
- Feldbrugge, 2017, Lorentzian Quantum Cosmology, Phys. Rev. D, 95, 103508, 10.1103/PhysRevD.95.103508 · DOI · Paper page
- Feldbrugge, 2017, No smooth beginning for spacetime, Phys. Rev. Lett., 119, 171301, 10.1103/PhysRevLett.119.171301 · DOI · Paper page
- Halliwell, 2017, Real no-boundary wave function in Lorentzian quantum cosmology, Phys. Rev. D, 96, 043505, 10.1103/PhysRevD.96.043505 · DOI · Paper page
- Feldbrugge, 2018, No rescue for the no boundary proposal: Pointers to the future of quantum cosmology, Phys. Rev. D, 97, 023509, 10.1103/PhysRevD.97.023509 · DOI · Paper page
- Diaz Dorronsoro, J., Halliwell, J.J., Hartle, J.B., Hertog, T., Janssen, O., and Vreys, Y. (arXiv, 2018). Damped perturbations in the no-boundary state, arXiv. · DOI · Paper page
- Vilenkin, 1984, Quantum Creation of Universes, Phys. Rev. D, 30, 509, 10.1103/PhysRevD.30.509 · DOI · Paper page
- Vilenkin, 1994, Approaches to quantum cosmology, Phys. Rev. D, 50, 2581, 10.1103/PhysRevD.50.2581 · DOI
- Vilenkin, 2018, Tunneling wave function of the universe, Phys. Rev. D, 98, 066003, 10.1103/PhysRevD.98.066003 · DOI · Paper page
- Misner, 1969, Mixmaster universe, Phys. Rev. Lett., 22, 1071, 10.1103/PhysRevLett.22.1071 · DOI · Paper page
- Halliwell, 1989, Steepest Descent Contours in the Path Integral Approach to Quantum Cosmology. 1. The De Sitter Minisuperspace Model, Phys. Rev. D, 39, 2206, 10.1103/PhysRevD.39.2206 · DOI
- Gielen, 2016, Perfect Quantum Cosmological Bounce, Phys. Rev. Lett., 117, 021301, 10.1103/PhysRevLett.117.021301 · DOI
- Gielen, 2017, Quantum propagation across cosmological singularities, Phys. Rev., 95, 103510
- Di Tucci, A., and Lehners, J.L. (arXiv, 2018). Unstable no-boundary fluctuations from sums over regular metrics, arXiv. · DOI
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Sorted by citations
On Quantum Creation of a Toroidal Universe
Guth, A. H., & Vilenkin, A. (2026) · Fundamental Theories of Physics · doi:10.1007/978-3-032-15703-4_8 · Cited by 4
Metadata
- Authors
- Feldbrugge, J., Lehners, J.-L., & Turok, N.
- Venue
- Universe
- Publisher
- MDPI AG
- Published
- 2018-09-29
- Volume
- 4
- Issue
- 10
- Pages
- 100
- ISSN
- 2218-1997
- Cited by
- 58
- References
- 2
- Language
- en
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