Causal three-point functions and nonlinear second-order hydrodynamic coefficients in AdS/CFT

In the context of N = 4 SYM, we compute the finite 't Hooft coupling lambda correction to the non-linear second-order hydrodynamic coefficient lambda(3) from a Kubo formula based on fully retarded three-point functions using AdS/CFT. Although lambda(3) is known to vanish in the infinite 't Hooft coupling limit, we find that the finite lambda correction is non-zero. We also present a set of Kubo formulae for the non-linear coefficients lambda(1,2,3,) which is more convenient than the one that has appeared recently elsewhere.