Kinetic Alfven solitons in a low-beta plasma

Kinetic Alfven solitons with hot electrons and finite electron inertia in a low-beta (beta = 8 pi n(0)T/B-G(2), the ratio of the kinetic to the magnetic pressure) plasma is studied analytically, with the ion motion being considered dominant through the polarization drift. Both compressive and rarefactive kinetic Alfven solitons are found to exist within a definite range of k(z) (the direction of propagation of the kinetic Alfven solitary waves with respect to the direction of the magnetic field) for each pair of assigned values of beta and M (Mach number). Unlike in precious theoretical investigations, beta appears as an explicit parameter for the kinetic Alfven solitons in this case. In addition, consideration of the electron pressure gradient is found to suppress the speed of both the Alfven solitons considerably for A (= 2QM(2)/beta k(z)(2), with Q the electron-to-ion mass ratio) less than unity.