Hardy--Littlewood Maximal Operator and Two-Layer Muckenhoupt Weights on Infinite Rooted k-Ary Trees
Abstract
Let kβ₯ 2 be an integer, T an infinite rooted k-ary tree, and M the Hardy--Littlewood maximal operator on T. For any pβ(0,β), we characterize the weight w such that M is bounded on Lp(w). To this end, we introduce a two-layer Muckenhoupt weight class πp and prove that, for any pβ(1/2,β), the boundedness of M on Lp(w), wβπp, and the exponential decay boundedness of spherical averaging operators on Lp(w) are mutually equivalent, and that, when pβ(0,1/2], there exists no weight w such that M is bounded on Lp(w). Moreover, for any pβ(1/2,β), we establish the quantitative estimate, with the optimal exponent 1/p of the weight constant, for the boundedness of M on Lp(w). For any pβ(1,β), we also obtain two further equivalent characterizations of the boundedness of M on Lp(w), respectively, in terms of a global Sawyer-type testing condition and an estimate for the weighted product measure of distance incidence sets. As applications, for any pβ(1/2,β), under the assumption that M is bounded on Lp(w), we establish the boundedness of exponentially decaying kernel operators on Lp(w) and weighted Fefferman--Stein vector-valued inequalities.
Related
- Muckenhoupt weights for the Hardy-Littlewood maximal operator on hyperbolic spaces
- The norm of the centered Hardy--Littlewood maximal operator
- Noncommutative Maximal Ergodic Theorems for Modulated (C,Ξ±)-Averages with Operator-Valued Weights
- A Note on Capacity Muckenhoupt Weights with respect to the Hausdorff Content
- Properties and applications of Muckenhoupt A1 growth weights
BibTeX
@misc{yang2026hardylittlewood,
title = {{Hardy--Littlewood Maximal Operator and Two-Layer Muckenhoupt Weights on Infinite Rooted $k$-Ary Trees}},
author = {Dachun Yang and Wen Yuan and Mingdong Zhang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.12844},
eprint = {2609.12844},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.12844},
}
RIS
TY - UNPB
TI - Hardy--Littlewood Maximal Operator and Two-Layer Muckenhoupt Weights on Infinite Rooted k-Ary Trees
AU - Dachun Yang
AU - Wen Yuan
AU - Mingdong Zhang
PY - 2026
DA - 2026/09/11
PB - arXiv
DO - 10.48550/arxiv.2609.12844
UR - https://arxiv.org/abs/2609.12844
AB - Let kβ₯ 2 be an integer, T an infinite rooted k-ary tree, and M the Hardy--Littlewood maximal operator on T. For any pβ(0,β), we characterize the weight w such that M is bounded on L^p(w). To this end, we introduce a two-layer Muckenhoupt weight class π_p and prove that, for any pβ(1/2,β), the boundedness of M on L^p(w), wβπ_p, and the exponential decay boundedness of spherical averaging operators on L^p(w) are mutually equivalent, and that, when pβ(0,1/2], there exists no weight w such that M is bounded on L^p(w). Moreover, for any pβ(1/2,β), we establish the quantitative estimate, with the optimal exponent 1/p of the weight constant, for the boundedness of M on L^p(w). For any pβ(1,β), we also obtain two further equivalent characterizations of the boundedness of M on L^p(w), respectively, in terms of a global Sawyer-type testing condition and an estimate for the weighted product measure of distance incidence sets. As applications, for any pβ(1/2,β), under the assumption that M is bounded on L^p(w), we establish the boundedness of exponentially decaying kernel operators on L^p(w) and weighted Fefferman--Stein vector-valued inequalities.
ER -