Boundary regularity of uniformly rotating vortex patches and an unstable elliptic free boundary problem
Yuchen Wang
Tianjin Normal University, P. R. ChinaGuanghui Zhang
Huazhong University of Science and Technology, Wuhan, P. R. ChinaMaolin Zhou
Nankai University, Tianjin, P. R. China

Abstract
In this paper, we consider the sign-changing free boundary problem related to the uniformly rotating vortex patch solutions of the two-dimensional incompressible Euler equations. We prove that the boundary of the vortex patch locally forms a corner near singular boundary points, if the patch is Lipschitz.
Cite this article
Yuchen Wang, Guanghui Zhang, Maolin Zhou, Boundary regularity of uniformly rotating vortex patches and an unstable elliptic free boundary problem. Ann. Inst. H. Poincaré C Anal. Non Linéaire (2026), published online first
DOI 10.4171/AIHPC/183