“…The AdS/CFT correspondence provides a new powerful method to compute the transport coefficients of strongly coupled systems that live on the boundary of asymptotically anti-de Sitter (AdS) space-times, including the ratio of shear viscosity to entropy density [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18] and thermal-electric conductivities (for nice reviews, see [19,20,21]). This is achieved by analysing small perturbations about the black holes background which describe the equilibrium state at finite temperature and chemical potential.…”