4 problems

Nieraeth's conjecture. If $M$ is bounded on $X$, then $M$ is bounded on $X'$.

Let $p_1,\ldots,p_m\in(1,\infty]$ with $\frac{1}{p}=\sum_{j=1}^m\frac{1}{p_j}>0$, and let $w=\prod_{j=1}^m w_j$. Suppose $T$ is well-defined on all $m$-tuples…

Let $T$ satisfy the full-range sparse domination bound referred to in the source. Let $X$ be a Banach function space such that $M:X\to X$ and $M:X'\to X'$ are bounded. Logarithmic…

Let $X( \Omega)$ be a Banach function space, and let the difference quotient criterion be the condition in which the estimate referenced as equation DQC1:1 characterizes membership…