Restricted weak type inequalities for the one-sided Hardy-Littlewood maximal operators in higher dimensions

TL;DR

This paper characterizes pairs of weights for which the one-sided Hardy-Littlewood maximal operator satisfies a restricted weak type inequality in higher dimensions, providing necessary and sufficient conditions with quantitative bounds.

Contribution

It provides a new quantitative characterization of weight pairs for restricted weak type inequalities of the one-sided maximal operator in higher dimensions, extending previous results.

Findings

Characterization of weight pairs in higher dimensions.

Necessary and sufficient conditions for restricted weak inequalities.

Extension of two-dimensional results to higher dimensions.

Abstract

We give a quantitative characterization of the pairs of weights $(w,v)$ for which the dyadic version of the one-sided Hardy-Littlewood maximal operator satisfies a restricted weak $(p,p)$ type inequality, for $1\leq p<\infty$. More precisely, given any measurable set $E_0$ the estimate \[w(\{x\in \mathbb{R}^n: M^{+,d}(\mathcal{X}_{E_0})(x)>t\})\leq \frac{C[(w,v)]_{A_p^{+,d}(\mathcal{R})}^p}{t^p}v(E_0)\] holds if and only if the pair $(w,v)$ belongs to $A_p^{+,d}(\mathcal{R})$, that is \[\frac{|E|}{|Q|}\leq [(w,v)]_{A_p^{+,d}(\mathcal{R})}\left(\frac{v(E)}{w(Q)}\right)^{1/p}\] for every dyadic cube $Q$ and every measurable set $E\subset Q^+$. The proof follows some ideas appearing in [Sheldy Ombrosi, \emph{Weak weighted inequalities for a dyadic one-sided maximal function in {$\Bbb R^n$}}, Proc. Amer. Math. Soc. \textbf{133} (2005), no.~6, 1769--1775]. We also obtain a similar quantitative characterization for the non-dydadic case in $\mathbb{R}^2$ by following the main ideas in [L.~Forzani, F.~J. Mart\'{\i}n-Reyes, and S.~Ombrosi, \emph{Weighted inequalities for the two-dimensional one-sided {H}ardy-{L}ittlewood maximal function}, Trans. Amer. Math. Soc. \textbf{363} (2011), no.~4, 1699--1719].