{ "id": "1911.13275", "version": "v1", "published": "2019-11-29T18:22:14.000Z", "updated": "2019-11-29T18:22:14.000Z", "title": "On strong infinite Sidon and $B_h$ sets and random sets of integers", "authors": [ "David Fabian", "Juanjo Rué", "Christoph Spiegel" ], "comment": "15 pages", "categories": [ "math.CO", "math.NT" ], "abstract": "A set of integers $S \\subset \\mathbb{N}$ is an $\\alpha$-strong Sidon set if the pairwise sums of its elements are far apart by a certain measure depending on $\\alpha$, more specifically if $| (x+w) - (y+z) | \\geq \\max \\{ x^{\\alpha},y^{\\alpha},z^{\\alpha},w^\\alpha \\}$ for every $x,y,z,w \\in S$ satisfying $\\{x,w\\} \\neq \\{y,z\\}$. We obtain a new lower bound for the growth of $\\alpha$-strong infinite Sidon sets when $0 \\leq \\alpha < 1$. We also further extend that notion in a natural way by obtaining the first non-trivial bound for $\\alpha$-strong infinite $B_h$ sets. In both cases, we study the implications of these bounds for the density of, respectively, the largest Sidon or $B_h$ set contained in a random infinite subset of $\\mathbb{N}$. Our theorems improve on previous results by Kohayakawa, Lee, Moreira and R\\\"odl.", "revisions": [ { "version": "v1", "updated": "2019-11-29T18:22:14.000Z" } ], "analyses": { "keywords": [ "random sets", "strong infinite sidon sets", "first non-trivial bound", "random infinite subset", "strong sidon set" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }