{ "id": "1903.11002", "version": "v1", "published": "2019-03-26T16:42:23.000Z", "updated": "2019-03-26T16:42:23.000Z", "title": "The Boundedness of the (Sub)Bilinear Maximal Function along \"non-flat\" smooth curves", "authors": [ "Alejandra Gaitan", "Victor Lie" ], "comment": "22 pages, 1 figure", "categories": [ "math.CA" ], "abstract": "Let $\\mathcal{N}\\mathcal{F}$ be the class of smooth non-flat curves near the origin and near infinity previously introduced by the second author and let $\\gamma\\in\\mathcal{N}\\mathcal{F}$. We show - via a unifying approach relative to the correspondent bilinear Hilbert transform $H_{\\Gamma}$ - that the (sub)bilinear maximal function along curves $\\Gamma=(t,-\\gamma(t))$ defined as $$M_{\\Gamma}(f,g)(x):=\\sup\\limits_{\\epsilon>0} \\frac{1}{2\\epsilon} \\int_{-\\epsilon}^{\\epsilon} |f(x-t)\\,g(x+\\gamma(t))|\\,dt$$ is bounded from $L^p(\\mathbb{R})\\times L^{q}(\\mathbb{R})\\to L^r(\\mathbb{R})$ for all $p, q$ and $r$ H\\\"older indices, that is $\\frac{1}{p}+\\frac{1}{q}=\\frac{1}{r}$, with $1