On the different analytical results obtained for the parallel diffusion coefficient of cosmic particles with adiabatic focusing

Abstract

A spatially varying mean magnetic field gives rise to so-called adiabatic focusing of energetic particles propagating through the universe. In the past, different analytical approaches have been proposed to calculate the particle diffusion coefficient along the mean field with focusing. In the present paper, we show how these different results are related to each other. New results for the parallel diffusion coefficient that are more general than previous results are also presented. © 2013. The American Astronomical Society. All rights reserved..