Infinite-dimensional symplectic non-squeezing using non-standard analysis

We prove a non-squeezing result for infinite-dimensional Hamiltonian flows using non-standard model theory. For this we prove the existence of a corresponding family of pseudoholomorphic spheres and characterize the maximal time in terms of a limiting behaviour for these curves. While our proof is based on the finite-dimensional results from Gromov’s original proof, we do not ask for any prior knowledge of non-standard model theory.