Collisionless Magnetic Reconnection in a Five - Moment Two - Fluid Electron - Positron Plasma

We study magnetic reconnection in electron-positron plasma using a collisionless two-fluid model with isotropic pressure, in which only the inertial term of the generalized Ohm's law is present. Our simulations indicate that the inertial term alone from Ohm's law is not sufficient to give reconnection. We contrast this result with other simulations where the Hall term is present (i.e., the ion/electron mass ratio is not 1), resistivity is also present, or where the pressures are allowed to be anisotropic. In each of these three cases fast reconnection appears to ensue.