  In the framework of chiral kinetic theory (CKT), we consider a system of
right- and left-handed Weyl fermions out of thermal equilibrium in a
homogeneous weak magnetic field. We show that the Lorentz invariance implies a
modification in the definition of the momentum current in the phase space,
compared to the case in which the system is in global equilibrium. Using this
modified momentum current, we derive the linearized conservation equations from
the kinetic equation up to second order in the derivative expansion. It turns
out that the eigenmodes of these equations, namely the hydrodynamic modes,
differ from those obtained from the hydrodynamic in the Landau-Lifshitz (LL)
frame at the same order. We show that the modes of the former case may be
transformed to the corresponding modes in the latter case by a global boost.
The velocity of the boost is proportional to the magnetic field as well as the
difference between the right- and left-handed charges susceptibility. We then
compute the chiral transport coefficients in a system of non-Abelian chiral
fermions in the no-drag frame and by making the above boost, obtain the
well-known transport coeffiecients of the system in the LL frame. Finally by
using the idea of boost, we reproduce the AdS/CFT result for the chiral drag
force exerted on a quark at rest in the rest frame of the fluid, without
performing any holographic computations.
