Time-dependent spacetimes in AdS/CFT: Bubble and black hole

TL;DR

This paper investigates time-dependent AdS spacetimes, specifically bubble and black hole solutions, analyzing their boundary duals, horizon thermodynamics, and vacuum ambiguities to identify the preferred quantum state in the dual CFT.

Contribution

It extends the understanding of time-dependent AdS/CFT by examining bubble and black hole solutions with de Sitter boundary, clarifying vacuum selection and horizon thermodynamics.

Findings

Euclidean vacuum is well-defined on the black hole solution.

The boundary dual is conformal to de Sitter space cross a circle.

The Euclidean vacuum is preferred in the dual CFT.

Abstract

We extend the study of time-dependent backgrounds in the AdS/CFT correspondence by examining the relation between bulk and boundary for the smooth 'bubble of nothing' solution and for the locally AdS black hole which has the same asymptotic geometry. These solutions are asymptotically locally AdS, with a conformal boundary conformal to de Sitter space cross a circle. We study the cosmological horizons and relate their thermodynamics in the bulk and boundary. We consider the alpha-vacuum ambiguity associated with the de Sitter space, and find that only the Euclidean vacuum is well-defined on the black hole solution. We argue that this selects the Euclidean vacuum as the preferred state in the dual strongly coupled CFT.