Relativistic Conformal Magneto-Hydrodynamics from Holography

We use the AdS/CFT correspondence to study first-order relativistic viscous magnetohydrodynamics of (2+1) dimensional conformal magnetic fluids. It is shown that the first order magneto-hydrodynamics constructed following Landau and Lifshitz from the positivity of the entropy production is inconsistent. We propose additional contributions to the entropy motivated dissipative current and, correspondingly, new dissipative transport coefficients. We use the strongly coupled M2-brane plasma in external magnetic field to show that the new magneto-hydrodynamics leads to self-consistent results in the shear and sound wave channels.