{ "id": "2203.04360", "version": "v1", "published": "2022-03-08T19:34:14.000Z", "updated": "2022-03-08T19:34:14.000Z", "title": "Mixed inequalities of Fefferman-Stein type for singular integral operators", "authors": [ "Fabio Berra", "Marilina Carena", "Gladis Pradolini" ], "comment": "17 pages", "categories": [ "math.CA" ], "abstract": "We give Feffermain-Stein type inequalities related to mixed estimates for Calder\\'on-Zygmund operators. More precisely, given $\\delta>0$, $q>1$, $\\varphi(z)=z(1+\\log^+z)^\\delta$, a nonnegative and locally integrable function $u$ and $v\\in \\mathrm{RH}_\\infty\\cap A_q$, we prove that the inequality \\[uv\\left(\\left\\{x\\in \\mathbb{R}^n: \\frac{|T(fv)(x)|}{v(x)}>t\\right\\}\\right)\\leq \\frac{C}{t}\\int_{\\mathbb{R}^n}|f|\\left(M_{\\varphi, v^{1-q'}}u\\right)M(\\Psi(v))\\] holds with $\\Psi(z)=z^{p'+1-q'}\\mathcal{X}_{[0,1]}(z)+z^{p'}\\mathcal{X}_{[1,\\infty)}(z)$, for every $t>0$ and every $p>\\max\\{q,1+1/\\delta\\}$. This inequality provides a more general version of mixed estimates for Calder\\'on-Zygmund operators proved in \\cite{CruzUribe-Martell-Perez}. It also generalizes the Fefferman-Stein estimates given in \\cite{P94} for the same operators. We further get similar estimates for operators of convolution type with kernels satisfying an $L^\\Phi-$H\\\"ormander condition, generalizing some previously known results which involve mixed estimates and Fefferman-Stein inequalities for these operators.", "revisions": [ { "version": "v1", "updated": "2022-03-08T19:34:14.000Z" } ], "analyses": { "keywords": [ "singular integral operators", "fefferman-stein type", "inequality", "mixed inequalities", "mixed estimates" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }