Front propagation in reaction-dispersal with anomalous distributions

The speed of pulled fronts for parabolic fractional-reaction-dispersal equations is derived and analyzed. From the continuous-time random walk theory we derive these equations by considering long-tailed distributions for waiting times and dispersal distances. For both cases we obtain the corresponding Hamilton-Jacobi equation and show that the selected front speed obeys the minimum action principle. We impose physical restrictions on the speeds and obtain the corresponding conditions between a dimensionless number and the fractional indexes. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2006