English

A modification of Hardy-Littlewood maximal-function on Lie groups

Functional Analysis 2023-01-18 v1

Abstract

For a real-valued function ff on a metric measure space (X,d,μ)(X,d,\mu) the Hardy-Littlewood maximal-function of ff is given by the following `supremum-norm': Mf(x):=supr>01μ(Bx,r)Bx,rfdμ.Mf(x):=\sup_{r>0}\frac{1}{\mu(\mathcal{B}_{x,r})}\int_{\mathcal{B}_{x,r}}|f|d\mu. In this note, we replace the supremum-norm on parameters rr by Lp\mathcal{L}_p-norm with weight ww on parameters rr and define Hardy-Littlewood integral-function Ip,wfI_{p,w}f. It is shown that Ip,wfI_{p,w}f converges pointwise to MfMf as pp\to\infty. Boundedness of the sublinear operator Ip,wI_{p,w} and continuity of the function Ip,wfI_{p,w}f in case that XX is a Lie group, dd is a left-invariant metric, and μ\mu is a left Haar-measure (resp. right Haar-measure) are studied.

Keywords

Cite

@article{arxiv.2301.07075,
  title  = {A modification of Hardy-Littlewood maximal-function on Lie groups},
  author = {Maysam Maysami Sadr},
  journal= {arXiv preprint arXiv:2301.07075},
  year   = {2023}
}