Density dependence of transport coefficients from holographic hydrodynamics

We study the transport coefficients of Quark-Gluon-Plasma in finite temperature and finite baryon density. We consider AdS/QCD of charged AdS black hole background with bulk-filling branes identifying the U(1) charge as the baryon number. Using Reissner-Nordstroem-AdS background, Green functions are explicitly obtained. We calculate the diffusion constant, the shear viscosity and the thermal conductivity, and plot their density and temperature dependences. Hydrodynamic relations between those are shown to hold exactly. The diffusion constant and the shear viscosity are decreasing as a function of density for fixed total energy. For fixed temperature, the fluid becomes less diffusible and more viscous for larger baryon density. (author)