Nucleating an inflationary universe: Euclidean wormholes and their no-boundary limit
Abstract
No-boundary instantons and Euclidean “wineglass” wormholes have both been proposed as providing suitable initial conditions for the current expanding phase of our universe, and in particular for providing conditions that are favorable to an inflationary phase. These finite action solutions have generally been regarded as unrelated, and enacting different scenarios – in one case the creation of spacetime from nothing, and in the other up-tunneling from an Anti-de Sitter vacuum. By studying explicit solutions of both axionic and magnetic wineglass wormholes, we find that in the zero-charge limit the throat of the wormholes pinches off, leaving a no-boundary instanton that disconnects from the asymptotic Anti-de Sitter region. Thus wormholes and no-boundary instantons are part of a common family of Euclidean solutions. Along the way, we resolve the long-known puzzle that the action of wineglass wormholes can become negative. Moreover, small-charge wormholes lead to a longer inflationary phase than large-charge solutions, while no-boundary instantons dominate the probability distribution overall.
Related
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BibTeX
@article{lavrelashvili2026nucleating,
title = {{Nucleating an inflationary universe: Euclidean wormholes and their no-boundary limit}},
author = {George Lavrelashvili and Jean-Luc Lehners},
journal = {Physics Letters B},
year = {2026},
month = oct,
doi = {10.1016/j.physletb.2026.141091},
url = {https://linkinghub.elsevier.com/retrieve/pii/S037026932600941X},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Nucleating an inflationary universe: Euclidean wormholes and their no-boundary limit
AU - George Lavrelashvili
AU - Jean-Luc Lehners
PY - 2026
DA - 2026/10/30
JO - Physics Letters B
DO - 10.1016/j.physletb.2026.141091
UR - https://linkinghub.elsevier.com/retrieve/pii/S037026932600941X
AB - No-boundary instantons and Euclidean “wineglass” wormholes have both been proposed as providing suitable initial conditions for the current expanding phase of our universe, and in particular for providing conditions that are favorable to an inflationary phase. These finite action solutions have generally been regarded as unrelated, and enacting different scenarios – in one case the creation of spacetime from nothing, and in the other up-tunneling from an Anti-de Sitter vacuum. By studying explicit solutions of both axionic and magnetic wineglass wormholes, we find that in the zero-charge limit the throat of the wormholes pinches off, leaving a no-boundary instanton that disconnects from the asymptotic Anti-de Sitter region. Thus wormholes and no-boundary instantons are part of a common family of Euclidean solutions. Along the way, we resolve the long-known puzzle that the action of wineglass wormholes can become negative. Moreover, small-charge wormholes lead to a longer inflationary phase than large-charge solutions, while no-boundary instantons dominate the probability distribution overall.
SN - 0370-2693
SN - 1873-2445
ER -