Black hole microstate cosmology

  • Sean Cooper
  • Moshe Rozali
  • Brian Swingle
  • Mark Van Raamsdonk
  • Christopher Waddell
  • David WakehamEmail author
Open Access
Regular Article - Theoretical Physics


In this note, we explore the possibility that certain high-energy holographic CFT states correspond to black hole microstates with a geometrical behind-the-horizon region, modelled by a portion of a second asymptotic region terminating at an end-of-the-world (ETW) brane. We study the time-dependent physics of this behind-the-horizon region, whose ETW boundary geometry takes the form of a closed FRW spacetime. We show that in many cases, this behind-the-horizon physics can be probed directly by looking at the time dependence of entanglement entropy for sufficiently large spatial CFT subsystems. We study in particular states defined via Euclidean evolution from conformal boundary states and give specific predictions for the behavior of the entanglement entropy in this case. We perform analogous calculations for the SYK model and find qualitative agreement with our expectations. We also calculate holographic complexity for the d = 2 ETW geometries, finding that complexity-action and complexity-volume proposals give the same linear growth at late times, but differ at early times.

A fascinating possibility is that for certain states, we might have gravity localized to the ETW brane as in the Randall-Sundrum II scenario for cosmology. In this case, the effective description of physics beyond the horizon could be a big bang/big crunch cosmology of the same dimensionality as the CFT. In this case, the d-dimensional CFT describing the black hole microstate would give a precise, microscopic description of the d-dimensional cosmological physics.


AdS-CFT Correspondence Black Holes in String Theory Conformal Field Theory Holography and condensed matter physics (AdS/CMT) 


Open Access

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.


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© The Author(s) 2019

Authors and Affiliations

  • Sean Cooper
    • 1
  • Moshe Rozali
    • 1
  • Brian Swingle
    • 2
  • Mark Van Raamsdonk
    • 1
  • Christopher Waddell
    • 1
  • David Wakeham
    • 1
    Email author
  1. 1.Department of Physics and AstronomyUniversity of British ColumbiaVancouverCanada
  2. 2.Condensed Matter Theory Center, Maryland Center for Fundamental Physics, Joint Center for Quantum Information and Computer Science, and Department of PhysicsUniversity of MarylandCollege ParkU.S.A.

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