2 problems

Let $\mathbb{G}$ be a graded Lie group with $\dim(\mathbb{G})\geq 2$, let $\mathcal{G}$ be a positive Rockland operator on $\mathbb{G}$, and let $\chi$ be the characteristic functi…

Mikhlin–Hörmander multiplier conjecture. The operator $m(G)$ is bounded on $L_p$ for $1<p<\infty$ and is of weak type $(1,1)$ whenever $s>1$.