2 problems

With $\mathfrak{W}$, $\Omega$, $d$, $\ell$, $k$, and $S^{d-1}$ as above, for $\alpha\in(0,d)$, the Besov--Lorentz strengthening. The Riesz potential $\operatorname{I}_{\alpha}$ map…

Let $d$ and $\ell$ be positive integers, let $S^{d-1}$ be the unit sphere in $\mathbb{R}^d$, and let $G(\ell,k)$ denote the Grassmannian of $k$-dimensional linear subspaces of…