Sean A. Hartnoll

A gravitational instability in higher dimensions

We explore a classical instability of spacetimes of dimension

Higher rank Wilson loops from a matrix model

Dg4.

Multiply wound Polyakov loops at strong coupling

First, we consider static solutions: generalized black holes and brane world metrics. The dangerous mode is a tensor mode on an Einstein base manifold of dimension

Rotating membranes on G2 manifolds, logarithmic anomalous dimensions and N = 1 duality

Densuremath{-}2.

Two universal results for Wilson loops at strong coupling

A criterion for instability is found for the generalized Schwarzschild, AdS-Schwarzschild and topological black hole spacetimes in terms of the Lichnerowicz spectrum on the base manifold. Secondly, we consider perturbations in time-dependent solutions: Generalized dS and AdS. Thirdly we show that, subject to the usual limitations of a linear analysis, any Ricci flat spacetime may be stabilized by embedding into a higher dimensional spacetime with cosmological constant. We apply our results to pure AdS black strings. Finally, we study the stability of higher dimensional ``bubbles of nothing.

AdS black holes and thermal Yang-Mills correlators

We compute the circular Wilson loop of = 4 SYM theory at large N in the rank k symmetric and antisymmetric tensor representations. Using a quadratic Hermitian matrix model we obtain expressions for all values of the t Hooft coupling. At large and small couplings we give explicit formulae and reproduce supergravity results from both D3 and D5 branes within a systematic framework.

The O(N) model on a squashed S3 and the Klebanov-Polyakov correspondence

We study the expectation value of a Polyakov-Maldacena loop that wraps the thermal circle k times in strongly coupled N = 4 super Yang-Mills theory. This is achieved by considering probe D3 and D5 brane embeddings in the dual black hole geometry. In contrast to multiply wound spatial Wilson loops, nontrivial dependence on k is captured through D5 branes. We find N −2/3 corrections, reminiscent of the scaling behaviour near a Gross-Witten transition.

On the Stability of Naked Singularities with Negative Mass

We show that the E−S ~ log S behaviour found for long strings rotating on AdS5 × S5 may be reproduced by membranes rotating on AdS4 × S7 and on a warped AdS5 M-theory solution. We go on to obtain rotating membrane configurations with the same E−K ~ log K relation on G2 holonomy backgrounds that are dual to {} = 1 gauge theories in four dimensions. We study membrane configurations on G2 holonomy backgrounds systematically, finding various other Energy-Charge relations. We end with some comments about strings rotating on warped backgrounds.

Deforming baryons into confining strings

We present results for Wilson loops in strongly coupled gauge theories. The loops may be taken around an arbitrarily shaped contour and in any field theory with a dual IIB geometry of the form

Iron line profiles from black hole accretion discs with spiral velocity structure

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