Symmetry in stationary and uniformly rotating solutions of active scalars

In this talk, I will discuss a Liouville type theorem for stationary
or uniformly-rotating solutions of 2D Euler and other similar
equations. The main question we want to address is whether every
stationary/uniformly-rotating solution must be radially symmetric.
Based on joint work with Jaemin Park, Jia Shi and Yao Yao.