Effective Field Theory of Force-Free Electrodynamics

Understand

Force-free electrodynamics (FFE) is a closed set of equations for the electromagnetic field of a magnetically dominated plasma.

• There are strong arguments for the existence of force-free plasmas near pulsars and active black holes, but FFE alone cannot account for the observational signatures, such as coherent radio emission and relativistic jets and winds.
• We reformulate FFE as the effective field theory of a cold string fluid and initiate a systematic study of corrections in a derivative expansion.
• At leading order the effective theory is equivalent to (generalized) FFE, with the strings comprised by magnetic field line worldsheets.