{ "id": "2008.05639", "version": "v1", "published": "2020-08-13T01:49:51.000Z", "updated": "2020-08-13T01:49:51.000Z", "title": "Fractional Integration and Optimal Estimates for Elliptic Systems", "authors": [ "Felipe Hernandez", "Daniel Spector" ], "comment": "22 pages", "categories": [ "math.AP", "math.FA" ], "abstract": "In this paper we prove the following optimal Lorentz embedding for the Riesz potentials: Let $\\alpha \\in (0,d)$. There exists a constant $C=C(\\alpha,d)>0$ such that \\[ \\|I_\\alpha F \\|_{L^{d/(d-\\alpha),1}(\\mathbb{R}^d;\\mathbb{R}^d)} \\leq C \\|F\\|_{L^1(\\mathbb{R}^d;\\mathbb{R}^d)} \\] for all fields $F \\in L^1(\\mathbb{R}^d;\\mathbb{R}^d)$ such that $\\operatorname*{div} F=0$ in the sense of distributions. We then show how this result implies optimal Lorentz regularity for a Div-Curl system (which can be applied, for example to obtain new estimates for the magnetic field in Maxwell's equations), as well as for a vector-valued Poisson equation in the divergence free case.", "revisions": [ { "version": "v1", "updated": "2020-08-13T01:49:51.000Z" } ], "analyses": { "keywords": [ "optimal estimates", "fractional integration", "elliptic systems", "result implies optimal lorentz regularity", "divergence free case" ], "note": { "typesetting": "TeX", "pages": 22, "language": "en", "license": "arXiv", "status": "editable" } } }