The shear viscosity of the non-commutative plasma

TL;DR

This paper calculates the shear viscosity of a non-commutative super Yang-Mills plasma at strong coupling using holographic duality, revealing universal behavior despite anisotropy.

Contribution

It demonstrates that shear viscosity to entropy ratio remains universal in anisotropic non-commutative theories and highlights the role of the open string metric in holographic energy momentum tensor.

Findings

b7 b7 b7 Shear viscosity to entropy ratio b1 1/4 extpi is preserved.

b7 b7 b7 The boundary energy momentum tensor couples to the open string metric.

b7 b7 b7 The holographic energy momentum tensor matches the commutative case.

Abstract

We compute the shear viscosity of the non-commutative N=4 super Yang-Mills quantum field theory at strong coupling using the dual supergravity background. Special interest derives from the fact that the background presents an intrinsic anisotropy in space through the distinction of commutative and non-commutative directions. Despite this anisotropy the analysis exhibits the ubiquitous result \eta/s = 1/4\pi for two different shear channels. In order to derive this result, we show that the boundary energy momentum tensor must couple to the open string metric. As a byproduct we compute the renormalised holographic energy momentum tensor and show that it coincides with one in the commutative theory.