In this work we investigate the process of pattern formation induced by
nonlinear diffusion in a reaction-diffusion system with Lotka-Volterra
predator-prey kinetics. We show that the cross-diffusion term is responsible of
the destabilizing mechanism that leads to the emergence of spatial patterns.
Near marginal stability we perform a weakly nonlinear analysis to predict the
amplitude and the form of the pattern, deriving the Stuart-Landau amplitude
equations. Moreover, in a large portion of the subcritical zone, numerical
simulations show the emergence of oscillating patterns, which cannot be
predicted by the weakly nonlinear analysis. Finally when the pattern invades
the domain as a travelling wavefront, we derive the Ginzburg-Landau amplitude
equation which is able to describe the shape and the speed of the wave.Comment: 15 pages, 5 figure