Causal hydrodynamics of gauge theory plasmas from AdS/CFT duality

Abstract

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.

Comments: 20 pages, ReVTeX4; v3: the sound mode results for SAdS_{4,7} added, an early interpretation based only on the shear mode changed; v6: corrected solution in Appendix B