%0 Journal Article
%T A sticky business: the status of the conjectured viscosity/entropy density bound
%A Cherman
%A Aleksey
%A Cohen
%A Thomas D.
%A Hohler
%A Paul M.
%J High Energy Physics - Phenomenology
%D 2007
%I 
%R 10.1088/1126-6708/2008/02/026
%X There have been a number of forms of a conjecture that there is a universal lower bound on the ratio, eta/s, of the shear viscosity, eta, to entropy density, s, with several different domains of validity. We examine the various forms of the conjecture. We argue that a number of variants of the conjecture are not viable due to the existence of theoretically consistent counterexamples. We also note that much of the evidence in favor of a bound does not apply to the variants which have not yet been ruled out.
%U http://arxiv.org/abs/0708.4201