A note on integrability loss in fuzzball geometries

We study the dynamics of certain string configurations in a class of fivebrane supertube backgrounds. In the decoupling limit of the fivebranes, these solutions are known to admit an exact description in worldsheet string theory and string propagation is integrable. For the asymptotically flat solutions, we prove, by using analytic tools of classical Hamiltonian systems, the non-integrability of classical string motion. This suggests that string dynamics in circular supertube geometries exhibit a regime of chaotic behaviour.