{ "id": "1601.07677", "version": "v1", "published": "2016-01-28T07:55:01.000Z", "updated": "2016-01-28T07:55:01.000Z", "title": "Restriction of averaging operators to algebraic varieties over finite fields", "authors": [ "Doowon Koh", "Seongjun Yeom" ], "comment": "15 pages, 1 figure", "categories": [ "math.CA" ], "abstract": "We study the mapping properties of restricted averaging operators related to algebraic varieties $V$ of $d$-dimensional vector spaces over finite fields $\\mathbb F_q$ with $q$ elements. Given an algebraic variety $V \\subset \\mathbb F_q^d,$ let us denote by $dx$ and $\\sigma$ the normalized counting measure on $\\mathbb F_q^d$ and the normalized surface measure on $V$, respectively. For functions $f: \\mathbb F_q^d \\to \\mathbb C$, a restricted averaging operator $A_V$ is defined by restricting $f\\ast \\sigma$ to the variety $V$, that is $A_Vf=f\\ast \\sigma|_V.$ The main purpose of this paper is to investigate $L^p\\to L^r$ estimates of the restricted averaging operator $A_V.$ We relate this problem to both the Fourier restriction problem and the averaging problem over $V\\subset \\mathbb F_q^d.$ As a consequence, we obtain the optimal results on the restricted averaging problems for regular varieties such as the spheres, the paraboloids for dimensions $d\\ge2,$ and the cones for odd dimensions $d\\ge 3.$ In addition, when the variety $V$ is the cone lying in an even dimensional vector space over $\\mathbb F_q$, we obtain the sharp weak-type estimates for restricted averaging operators $A_V.$", "revisions": [ { "version": "v1", "updated": "2016-01-28T07:55:01.000Z" } ], "analyses": { "subjects": [ "42B05", "11T23" ], "keywords": [ "algebraic variety", "restricted averaging operator", "finite fields", "dimensional vector space", "averaging problem" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160107677K" } } }