  We study causal hydrodynamics (Israel-Stewart theory) of gauge theory plasmas
from the AdS/CFT duality. Causal hydrodynamics requires new transport
coefficients (relaxation times) and we compute them for a number of
supersymmetric gauge theories including the N=4 SYM. However, the relaxation
times obtained from the "shear mode" do not agree with the ones from the "sound
mode," which implies that the Israel-Stewart theory is not a sufficient
framework to describe the gauge theory plasmas.
