  We study the collective excitations in a dissipative charged fluid at zero
chemical potential when an external magnetic field is present. While in the
absence of magnetic field, four collective excitations appear in the fluid, we
find five hydrodynamic modes in presence of magnetic field. This implies that
the magnetic field splits the degeneracy between the transverse shear modes.
Using linear response theory, we then compute the retarded response functions.
In particular, it turns out that the correlation between charge and the energy
fluctuations will no longer vanish, even at zero chemical potential. By use of
the response functions, we also derive the relevant Kubo formulas for the
transport coefficients.
