Traversable wormholes via a double trace deformation
Ping Gao · Daniel Louis Jafferis · Aron C. Wall
Open licence · full text · CC BY 4.0
In one page
Ping Gao, Daniel Jafferis and Aron Wall take the oldest obstacle in wormhole physics and find the way around it. A wormhole you could actually travel through needs matter whose energy averages negative along the light ray that crosses it, and a long line of theorems says you cannot arrange that. Their move is to take an eternal black hole with two mouths in two separate asymptotic regions and switch on a small direct coupling between the two boundaries at a chosen moment. That coupling changes the boundary condition on a quantum field in the throat, and the resulting quantum stress energy is negative on average along the crossing ray — the same family of effect as the Casimir force between two plates, because the coupling makes the radial direction behave like a closed loop. The Einstein–Rosen bridge opens. It stays open only briefly, it cannot be used to outrun light through ordinary space or to build a time machine, and the authors argue it is quantum teleportation seen from the inside.
Why it matters hereChapter 4 usually has to stop at ’a traversable wormhole needs exotic matter’; this is the paper that supplies the exotic matter from an ordinary quantum field and a coupling you can write down, and the authors state it is the first traversable wormhole shown to be embeddable in a UV-complete theory of gravity. It also lands squarely in chapter 2, because the negative average null energy it uses is Casimir physics — the vacuum reorganised by a boundary condition, not a new substance.
What it claims
01Turning on an interaction that couples the two boundaries of an eternal BTZ black hole produces a quantum matter stress tensor with negative average null energy, whose gravitational backreaction renders the Einstein–Rosen bridge traversable.Abstract; Section 1, Introduction
Published and peer-reviewed02The integrated null energy along the horizon comes out negative for every operator dimension between zero and one, and the earlier the coupling is turned on the larger the effect — so the wormhole stays open even though the local null energy turns positive again at late times.Section 3, closed-form result at Equation 3.18 and figure 3
Published and peer-reviewed03The negative energy in this configuration is similar to the Casimir effect, because the interaction between the boundaries makes the radial direction effectively a compact circle.Section 1, Introduction; Section 5, Discussion
Published and peer-reviewed04This is the first traversable wormhole solution that has been shown to be embeddable in a UV complete theory of gravity, since the double trace deformation used is relevant and therefore a renormalizable deformation of the boundary conformal field theory.Section 1, Introduction
Published and peer-reviewed05The construction cannot be used to violate causality: the coupling breaks the Killing symmetry between the two boundaries and so fixes their relative time coordinate, excluding closed time-like curves, and the throat opens only by an amount proportional to the coupling strength.Section 5, Discussion, around Equation 5.1
Published and peer-reviewed06The authors propose that the gravitational dual description of quantum teleportation, understood as a dynamical process, is a qubit passing through the ER=EPR wormhole of an entangled pair that the required interaction has rendered traversable.Section 5, Discussion, quantum teleportation interpretation
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Traversable wormholes via a double trace deformation
Ping Gao and Daniel Louis Jafferis, Center for the Fundamental Laws of Nature, Harvard University; Aron C. Wall, School of Natural Sciences, Institute for Advanced Study, Princeton.
Journal of High Energy Physics, JHEP12(2017)151. Received 14 September 2017; accepted 14 December 2017; published 28 December 2017. arXiv preprint 1608.05687.
Abstract
After turning on an interaction that couples the two boundaries of an eternal BTZ black hole, we find a quantum matter stress tensor with negative average null energy, whose gravitational backreaction renders the Einstein-Rosen bridge traversable. Such a traversable wormhole has an interesting interpretation in the context of ER=EPR, which we suggest might be related to quantum teleportation. However, it cannot be used to violate causality. We also discuss the implications for the energy and holographic entropy in the dual CFT description.
Keywords: Black Holes, Gauge-gravity correspondence.
(Abstract only. The paper's five sections and appendix are a detailed hypergeometric calculation whose equations do not survive plain-text extraction intact; the complete text is at the source under the same CC BY 4.0 licence.)
The way in
https://doi.org/10.1007/JHEP12(2017)151The paper closes with the statement ’This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0)’ and was funded by SCOAP3, so the full text is freely redistributable. Only the authors’ own abstract is reproduced here; the paper is a dense hypergeometric calculation whose equations do not survive plain-text extraction intact, so the complete text is best read at the source or in the arXiv preprint 1608.05687.
How to cite it
Ping Gao, Daniel Louis Jafferis, Aron C. Wall (2017) Traversable wormholes via a double trace deformation. doi:10.1007/JHEP12(2017)151
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