Hydrodynamics of Sakai-Sugimoto model in the quenched approximation

We study transport properties of the finite temperature Sakai-Sugimoto model. The model represents a holographic dual to (4+1)-dimensional supersymmetric SU(Nc) gauge theory compactified on a circle with anti-periodic boundary conditions for fermions, coupled to Nf left-handed quarks and Nf right-handed quarks localized at different points on the compact circle. We analytically compute the speed of sound and the sound wave attenuation in the quenched approximation. Since confinement/deconfinement (and the chiral symmetry restoration) phase transitions are first order in this model, we do not see any signature of these phase transitions in the transport properties.