Instabilities of Black Strings and Branes

TL;DR

This paper reviews the recent understanding of the Gregory-Laflamme instability affecting black strings and branes in higher-dimensional and supergravity theories, exploring classical, thermodynamic, and holographic implications.

Contribution

It provides a comprehensive review of the classical and thermodynamic stability of black strings and branes, including new phase structures and the connection to holography.

Findings

Detailed analysis of neutral black string instability

Identification of new phases and horizon-topology transitions

Implications for holographic theories like Yang-Mills and Little String Theory

Abstract

We review recent progress on the instabilities of black strings and branes both for pure Einstein gravity as well as supergravity theories which are relevant for string theory. We focus mainly on Gregory-Laflamme instabilities. In the first part of the review we provide a detailed discussion of the classical gravitational instability of the neutral uniform black string in higher dimensional gravity. The uniform black string is part of a larger phase diagram of Kaluza-Klein black holes which will be discussed thoroughly. This phase diagram exhibits many interesting features including new phases, non-uniqueness and horizon-topology changing transitions. In the second part, we turn to charged black branes in supergravity and show how the Gregory-Laflamme instability of the neutral black string implies via a boost/U-duality map similar instabilities for non- and near-extremal smeared branes in string theory. We also comment on instabilities of D-brane bound states. The connection between classical and thermodynamic stability, known as the correlated stability conjecture, is also reviewed and illustrated with examples. Finally, we examine the holographic implications of the Gregory-Laflamme instability for a number of non-gravitational theories including Yang-Mills theories and Little String Theory.