Classification of magnetohydrodynamic transport at strong magnetic field

Understand

Magnetohydrodynamics is a theory of long-lived, gapless excitations in plasmas.

• It was argued from the point of view of fluid with higher-form symmetry that magnetohydrodynamics remains a consistent, non-dissipative theory even in the limit where temperature is negligible compared to the magnetic field.
• In this limit, leading-order corrections to the ideal magnetohydrodynamics arise at the second order in the gradient expansion of relevant fields, not at the first order as in the standard hydrodynamic theory of dissipative fluids and plasmas.
• In this paper, we classify the non-dissipative second-order transport by constructing the appropriate non-linear effective action.