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General Relativistic Wormhole Connections from Planck-Scales and the ER = EPR Conjecture

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 Added by Fabrizio Tamburini
 Publication date 2019
  fields Physics
and research's language is English




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Einsteins equations of general relativity (GR) can describe the connection between events within a given hypervolume of size $L$ larger than the Planck length $L_P$ in terms of wormhole connections where metric fluctuations give rise to an indetermination relationship that involves the Riemann curvature tensor. At low energies (when $L gg L_P$), these connections behave like an exchange of a virtual graviton with wavelength $lambda_G=L$ as if gravitation were an emergent physical property. Down to Planck scales, wormholes avoid the gravitational collapse and any superposition of events or space--times become indistinguishable. These properties of Einsteins equations can find connections with the novel picture of quantum gravity (QG) known as the ``Einstein--Rosen (ER)=Einstein--Podolski--Rosen (EPR) (ER = EPR) conjecture proposed by Susskind and Maldacena in Anti-de-Sitter (AdS) space--times in their equivalence with conformal field theories (CFTs). In this scenario, non-traversable wormhole connections of two or more distant events in space--time through Einstein--Rosen (ER) wormholes that are solutions of the equations of GR, are supposed to be equivalent to events connected with non-local Einstein--Podolski--Rosen (EPR) entangled states that instead belong to the language of quantum mechanics. Our findings suggest that if the ER = EPR conjecture is valid, it can be extended to other different types of space--times and that gravity and space--time could be emergent physical quantities if the exchange of a virtual graviton between events can be considered connected by ER wormholes equivalent to entanglement connections.

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In this paper, we provide a counter-example to the ER=EPR conjecture. In an anti-de Sitter space, we construct a pair of maximally entangled but separated black holes. Due to the vacuum decay of the anti-de Sitter background toward a deeper vacuum, these two parts can be trapped by bubbles. If these bubbles are reasonably large, then within the scrambling time, there should appear an Einstein-Rosen bridge between the two black holes. Now by tracing more details on the bubble dynamics, one can identify parameters such that one of the two bubbles either monotonically shrinks or expands. Because of the change of vacuum energy, one side of the black hole would evaporate completely. Due to the shrinking of the apparent horizon, a signal of one side of the Einstein-Rosen bridge can be viewed from the opposite side. We analytically and numerically demonstrate that within a reasonable semi-classical parameter regime, such process can happen. Bubbles are a non-perturbative effect, which is the crucial reason that allows the transmission of information between the two black holes through the Einstein-Rosen bridge, even though the probability is highly suppressed. Therefore, the ER=EPR conjecture cannot be generic in its present form and its validity maybe restricted.
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