On the Einstein Relation in holographic systems at finite baryon density
  We study the conductivity, susceptibility and diffusion of a strongly coupled quark gluon plasma from the holographic perspective. We calculate general expressions for these quantities in the presence of finite baryon density and show that in this context, for the D3/D7 intersection the Einstein relation holds, providing another non-trivial check of the holographic correspondence at finite temperature. 
Javier Mas, Jonathan P. Shock, Javier Tarrio