{ "id": "2502.05882", "version": "v1", "published": "2025-02-09T12:47:07.000Z", "updated": "2025-02-09T12:47:07.000Z", "title": "Maximal operators on spaces BMO and BLO", "authors": [ "Grigori A. Karagulyan" ], "comment": "24 pages. arXiv admin note: text overlap with arXiv:2308.02672", "categories": [ "math.CA" ], "abstract": "We consider maximal kernel-operators on abstract measure spaces $(X,\\mu)$ equipped with a ball-basis. We prove that under certain asymptotic condition on the kernels those operators maps boundedly BMO(X) into BLO(X), generalizing the well-known results of Bennett-DeVore-Sharpley and Bennett for the Hardy-Littlewood maximal function. As a particular case of such an operator one can consider the maximal function \\begin{equation} M_\\phi f(x)=\\sup_{r>0}\\frac{1}{r^d}\\int_{R^d}|f(t)|\\phi\\left(\\frac{x-t}{r}\\right)dt, \\end{equation} and its non-tangential version. Here $\\phi(x)\\ge 0$ is a bounded spherical function on $R^d$, decreasing with respect to $|x|$ and satisfying the bound \\begin{equation*} \\int_{R^d}\\phi (x)\\log (2+|x|)dx<\\infty. \\end{equation*} We prove that if $f\\in BMO(R^d)$ and $M_\\phi(f)$ is not identically infinite, then $M_\\phi(f)\\in BLO(R^d)$. Our main result is an inequality, providing an estimation of certain local oscillation of the maximal function $M(f)$ by a local sharp function of $f$.", "revisions": [ { "version": "v1", "updated": "2025-02-09T12:47:07.000Z" } ], "analyses": { "subjects": [ "42B25", "42B35", "43A85" ], "keywords": [ "maximal operators", "spaces bmo", "local sharp function", "operators maps boundedly bmo", "hardy-littlewood maximal function" ], "note": { "typesetting": "TeX", "pages": 24, "language": "en", "license": "arXiv", "status": "editable" } } }