Sharp restricted weak-type estimates for sparse operators
Irina Holmes Fay, Guillermo Rey, Kristina Ana Škreb
Abstract
We find the exact Bellman function associated to the level-sets of sparse operators acting on characteristic functions.
Irina Holmes Fay, Guillermo Rey, Kristina Ana Škreb
We find the exact Bellman function associated to the level-sets of sparse operators acting on characteristic functions.
This paper contains 7 sections, 20 theorems, 194 equations, 19 figures.
Corollary 1
If $\mathcal{S}$ is sparse, $E \subseteq [0,1)$, $|E| = 2^{-n}$, and $\lambda \in \mathbb{N} - 2^{-n}$ is at least $2$, then and equality is attained for certain pairs $(E, \mathcal{S})$.