Morphology transitions in a mean-field model of diffusion-limited growth

We study a recently proposed mean-field theory relevant for diffusion-limited growth at finite undercooling. This theory exhibits a morphology transition from convex patterns, typical of the dense-branching morphology envelope, to concave ones, typical of the dendritic morphology envelope. This transition occurs as the undercooling is lowered at fixed anisotropy, but does not involve any discontinuous behavior of growth velocity.