Parameter regimes of applicability of the CGL equations of state in PIC simulations of fast magnetic reconnection

Abstract:

Recent literature shows that an electron pressure anisotropy which develops from the Chew-Goldberger-Low (CGL) equations of state in two-dimensional magnetohydrodynamic (MHD) simulations can yield fast reconnection rates. In the case of guide field reconnection, where the CGL equations of state are most valid, the electron pressure anisotropy can bring about fast reconnection even without the Hall term. We perform PIC simulations to compare with the MHD simulations of the CGL equations of state, spanning a parameter space in guide field strength and electron beta. We determine the appropriate parameter regimes of where the CGL equations of state are valid in the PIC simulations, investigate the transitions where the CGL equations of state break down, and compare those regimes of applicability with theoretical predictions.