{ "id": "1812.11419", "version": "v1", "published": "2018-12-29T18:29:42.000Z", "updated": "2018-12-29T18:29:42.000Z", "title": "Capacitary differentiability of potentials of finite Radon measures", "authors": [ "Joan Verdera" ], "comment": "13 pages", "categories": [ "math.CA" ], "abstract": "We study differentiability properties of a potential of the type $K\\star \\mu$, where $\\mu$ is a finite Radon measure in $\\mathbb{R}^N$ and the kernel $K$ satisfies $|\\nabla^j K(x)| \\le C\\, |x|^{-(N-1+j)}, \\quad j=0,1,2.$ We introduce a notion of differentiability in the capacity sense, where capacity is classical capacity in the de la Vall\\'ee Poussin sense associated with the kernel $|x|^{-(N-1)}.$ We require that the first order remainder at a point is small when measured by means of a normalized weak capacity \"norm\" in balls of small radii centered at the point. This implies weak $L^{N/(N-1)}$ differentiability and thus $L^{p}$ differentiability in the Calder\\'on--Zygmund sense for $1\\le p < N/(N-1)$. We show that $K\\star \\mu$ is a.e. differentiable in the capacity sense, thus strengthening a recent result by Ambrosio, Ponce and Rodiac. We also present an alternative proof of a quantitative theorem of the authors just mentioned, giving pointwise Lipschitz estimates for $K\\star \\mu.$ As an application, we study level sets of newtonian potentials of finite Radon measures.", "revisions": [ { "version": "v1", "updated": "2018-12-29T18:29:42.000Z" } ], "analyses": { "subjects": [ "42B20" ], "keywords": [ "finite radon measure", "capacitary differentiability", "capacity sense", "study level sets", "study differentiability properties" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }