English

Restricted testing for positive operators

Classical Analysis and ODEs 2019-09-13 v2

Abstract

We prove that for certain positive operators TT, such as the Hardy-Littlewood maximal function and fractional integrals, there is a constant D>1D>1, depending only on the dimension nn, such that the two weight norm inequality \begin{equation*} \int_{\mathbb{R}^{n}}T\left( f\sigma \right) ^{2}d\omega \leq C\int_{\mathbb{ R}^{n}}f^{2}d\sigma \end{equation*} holds for all f0f\geq 0 if and only if the (fractional) A2A_{2} condition holds, and the restricted testing condition \begin{equation*} \int_{Q}T\left( 1_{Q}\sigma \right) ^{2}d\omega \leq C\left\ | Q\right\ |_{\sigma } \end{equation*} holds for all cubes QQ satisfying \left\ | 2Q\right\ |_{\sigma }\leq D\left\ | Q\right\ |_{\sigma }. If TT is linear, we require as well that the dual restricted testing condition \begin{equation*} \int_{Q}T^{\ast }\left( 1_{Q}\omega \right) ^{2}d\sigma \leq C\left\ | Q\right\ |_{\omega } \end{equation*} holds for all cubes QQ satisfying \left\ | 2Q\right\ |_{\omega }\leq D\left\ | Q\right\ |_{\omega }.

Keywords

Cite

@article{arxiv.1809.04873,
  title  = {Restricted testing for positive operators},
  author = {Tuomas P. Hytönen and Kangwei Li and Eric T. Sawyer},
  journal= {arXiv preprint arXiv:1809.04873},
  year   = {2019}
}

Comments

This version also updates arXiv:1811.11032, 18 pages