Comments on Cosmic Censorship in AdS/CFT

TL;DR

This paper critically examines the claim that cosmic censorship can be violated in AdS/CFT, finding no conclusive evidence for such violations and discussing potential instabilities in related models.

Contribution

The authors analyze the models proposed by HHM, develop an improved lower bound on singularity size, and suggest an alternative AdS_3 example to avoid instabilities.

Findings

No initial data provably violate cosmic censorship in the studied models.

Configurations near the lower energy bound may lead to naked singularities in time evolution.

The full 10D theory exhibits instabilities in the finite radius cutoff AdS_5 scenario.

Abstract

Recently Hertog, Horowitz, and Maeda (HHM) (hep-th/0310054) have proposed that cosmic censorship can be violated in the AdS/CFT context. They argue that for certain initial data there is insufficient energy available to make a black hole whose horizon is big enough to cloak the singularity that forms. We have investigated this proposal in the models HHM discuss and have thus far been unable to find initial data that provably satisfy this criterion, despite our development of an improved lower bound on the size of the singular region. This is consistent with recent numerical results (hep-th/0402109). For certain initial data, the energies of our configurations are not far above the lower bound on the requisite black hole mass, and so it is possible that in the exact time development naked singularities do form. We go on to argue that the finite radius cut-off AdS_5 situation discussed by HHM displays instabilities when the full 10D theory is considered. We propose an AdS_3 example that may well be free of this instability.