2 problems

Shnirelman–Šverák relaxation conjecture. The set $\mathcal{A}_\infty$ consists of precisely those $f\in L^\infty(\Omega)$ for which $\{\mathcal{S}_t(f)\}_{t\in\mathbb{R}}$ is pre-c…

Let $y_m$ be a stationary streamline, so that $U'(y_m)=0$, and let $\psi(y,t)$ be the stream function with velocity components $v_x(y,t)$ and $v_y(y,t)=ik\psi(y,t)$. Here $U$ is th…