Stripe Formation in Bose-Einstein Condensates with Large Numbers of Vortices

We analyze recent experiments at JILA which observe periodic formation of stripes in a rotating Bose condensate [Engels et al. Phys. Rev. Lett. {\bf 89}, 100403 (2002)], and explain this behavior as a consequence of kinetic energy driven evolution, where the vortices follows a quadrupolar flow. We demonstrate that the structure of vortex lattices in the lowest Landau level is a useful tool for understanding such complex phenomena, even when the system is not in the quantum Hall regime.