Effective field theory of magnetohydrodynamics from generalized global symmetries

Understand

We introduce an effective action for non-dissipative magnetohydrodynamics.

• A crucial guiding principle is the generalized global symmetry of electrodynamics, which naturally leads to introducing a "dual photon" as the degree of freedom responsible for the electromagnetic component of the fluid.
• The formalism includes additional degrees of freedom and symmetries which characterize the hydrodynamic regime.
• By suitably enhancing one of the symmetries, the theory becomes force-free electrodynamics.