Cosmology from confinement?

Mark Van Raamsdonk

doi:10.1007/jhep03(2022)039

Abstract

We describe a class of holographic models that may describe the physics of certain four-dimensional big-bang/big-crunch cosmologies. The construction involves a pair of 3D Euclidean holographic CFTs each on a homogeneous and isotropic space M coupled at either end of an interval ℐ to a Euclidean 4D CFT on M × ℐ with many fewer local degrees of freedom. We argue that in some cases, when the size of M is much greater than the length of ℐ, the theory flows to a confining three-dimensional field theory on M in the infrared, and this is reflected in the dual description by the asymptotically AdS spacetimes dual to the two 3D CFTs joining up in the IR to give a Euclidean wormhole. The Euclidean construction can be reinterpreted as generating a state of the Lorentzian 4D CFT on M × time whose dual includes the physics of a big-bang/big-crunch cosmology. When M is ℝ3, we can alternatively analytically continue one of the ℝ3 directions to get an eternally traversable four-dimensional planar wormhole. We suggest explicit microscopic examples where the 4D CFT is mathcal{N} = 4 SYM theory and the 3D CFTs are superconformal field theories with opposite orientation. In this case, the two geometries dual to the pair of 3D SCFTs can be understood as a geometrical version of a brane-antibrane pair, and the tendency of the geometries to connect up is related to the standard instability of brane-antibrane systems.

Highlights

Be dual to asymptotically AdS black hole spacetimes with a dynamical end-of-the-world (ETW) brane providing an inner boundary for the spacetime behind the horizon of the black hole
We describe a class of holographic models that may describe the physics of certain four-dimensional big-bang/big-crunch cosmologies
We argue that in some cases, when the size of M is much greater than the length of I, the theory flows to a confining three-dimensional field theory on M in the infrared, and this is reflected in the dual description by the asymptotically AdS spacetimes dual to the two 3D CFTs joining up in the IR to give a Euclidean wormhole

Summary

Introduction

Be dual to asymptotically AdS black hole spacetimes with a dynamical end-of-the-world (ETW) brane providing an inner boundary for the spacetime behind the horizon of the black hole. We emphasize that the construction may continue to work when the 4D theory is not a conventional holographic theory (but the boundary theories involved in constructing the state are) In this case, there can be a classical gravitational description for the ETW brane (as a 4D theory of gravity, perhaps with a compact internal space) but no classical bulk 5D spacetime. While we don’t attempt to construct the relevant supergravity solutions in detail, we are able to describe the asymptotic behaviour explicitly. It remains to check (or argue indirectly) that the proposed solutions exist and have the conjectured properties.

Objectives

Discussion

Conclusion