An improved nonlinear theory for the perpendicular transport of charged particles is presented. This approach is based on an improved nonlinear treatment of field-line random walk in combination with a generalized compound diffusion model. The generalized compound diffusion model employed is much more systematic and reliable, in comparison to previous theories such as the nonlinear guiding center theory. Furthermore, the new theory shows remarkably good agreement with test-particle simulations and heliospheric observations.

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 1 (SH), pages 405-408