Weighted Solyanik Estimates for the Hardy-Littlewood maximal operator and embedding of $A_\infty$ into $A_p$

Abstract

Let $w$ denote a weight in $\mathbb{R}^n$ which belongs to the Muckenhoupt class $A_\infty$ and let $\mathsf{M}_w$ denote the uncentered Hardy-Littlewood maximal operator defined with respect to the measure $w(x)dx$. The \emph{sharp Tauberian constant} of $\mathsf M_w$ with respect to $\alpha$, denoted by $\mathsf{C}_w (\alpha)$, is defined by \[ \mathsf{C}_w (\alpha) := \sup_{E:\, 0 < w(E) < \infty}w(E)^{-1}w\big(\big\{x \in \mathbb{R}^n:\, \mathsf{M}_w \chi_E (x) > \alpha\big\}\big). \] In this paper, we show that the Solyanik estimate \[ \lim_{\alpha \rightarrow 1^-}\mathsf{C}_w(\alpha) = 1 \] holds. Following the classical theme of weighted norm inequalities we also consider the sharp Tauberian constants defined with respect to the usual uncentered Hardy-Littlewood maximal operator $\mathsf M$ and a weight $w$: \[ \mathsf C ^w (\alpha) := \sup_{E:\, 0 < w(E) < \infty} w(E)^{-1} w\big(\big\{x \in \mathbb R^n:\, \mathsf{M} \chi_E (x) > \alpha\big\}\big). \] We show that we have $\lim_{\alpha\to 1^{-}}\mathsf{C}^w(\alpha)=1$ if and only if $w\in A_\infty$. As a corollary of our methods we obtain a quantitative embedding of $A_\infty$ into $A_p$.