Global Regularity and Fast Small Scale Formation for Euler Patch Equation in a Smooth Domain

It is well known that the Euler vortex patch in ${\mathbb{R}}^2$ will remain regular if it is regular enough initially. In bounded domains, the regularity theory for patch solutions is less complete. In this paper, we study Euler vortex patches in a general smooth bounded domain. We prove global in time regularity by providing an upper bound on the growth of curvature of the patch boundary. For a special symmetric scenario, we construct an example of double exponential curvature growth, showing that our upper bound is qualitatively sharp.