Rapid Energy Dissipation by Colliding Waves in Strongly Magnetized Plasmas

Abstract

Rapid dissipation of magnetic energy in highly magnetized environments around neutron stars and black holes is a key open question in high-energy astrophysics. We develop a general kinetic picture of counter-propagating wave collisions in magnetized pair plasmas for arbitrary polarizations and find that magnetic energy can be dissipated on the wave-crossing timescale. The two magnetohydrodynamical conditions on the field invariants, $I_1\equiv B^2-E^2>0$ and $I_2\equiv \mathbf{E}\cdot \mathbf{B}=0$, can be spontaneously violated during the collision. Parallel electric fields develop to screen nonzero $I_2$ with little energy loss, consistent with the evolution described by Force-Free Electrodynamics. When magnetic dominance is lost, strong particle energization is triggered, dissipating magnetic energy on the wave-crossing timescale. This dynamical process yields a rapid dissipation channel of magnetic energy and provides a kinetic pathway to high-energy emission.

11 pages, 11 figures