{ "id": "2005.13839", "version": "v1", "published": "2020-05-28T08:29:48.000Z", "updated": "2020-05-28T08:29:48.000Z", "title": "Estimating the average of functions with convexity properties by means of a new center", "authors": [ "Bernardo González Merino" ], "comment": "20 pages", "categories": [ "math.FA", "math.MG" ], "abstract": "In this article we show the following result: if $C$ is an n-dimensional convex and compact set, $f:C\\rightarrow[0,\\infty)$ is concave, and $\\phi:[0,\\infty)\\rightarrow[0,\\infty)$ is a convex function with $\\phi(0)=0$, then \\[ \\int_C\\phi(f(x))dx \\leq \\max_{R}\\int_R\\phi(g(x))dx. \\] The maximum above ranges over the set of truncated cones $R$ with the same volume than $C$ and $g$ is an affine function which becomes zero at one of the bases of $R$ with $g(x_{R,g})=f(x_{C,f})$. Moreover, given such $C$ and $f$, we introduce a new point $x_{C,f}\\in C$, which divides evenly the mass distribution of $C$. As a consequence, we obtain a generalization of the type of results [Thm. 1.2, GM] and [Lem. 1.1, MP]. Besides, we also obtain some new estimates on the volume of particular sections of a convex set passing through $x_{C,f}$.", "revisions": [ { "version": "v1", "updated": "2020-05-28T08:29:48.000Z" } ], "analyses": { "keywords": [ "convexity properties", "compact set", "n-dimensional convex", "convex function", "estimating" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }