Javier Cilleruelo , Oriol Serra , Maximilian Wötzel
{"title":"Set systems with distinct sumsets","authors":"Javier Cilleruelo , Oriol Serra , Maximilian Wötzel","doi":"10.1016/j.endm.2018.06.004","DOIUrl":null,"url":null,"abstract":"<div><p>A family <span><math><mi>A</mi></math></span> of <em>k</em>-subsets of <span><math><mo>{</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>,</mo><mo>…</mo><mo>,</mo><mi>N</mi><mo>}</mo></math></span> is a Sidon system if the sumsets <span><math><mi>A</mi><mo>+</mo><msup><mrow><mi>A</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>,</mo><mi>A</mi><mo>,</mo><msup><mrow><mi>A</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>∈</mo><mi>A</mi></math></span> are pairwise distinct. We show that the largest cardinality <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>k</mi></mrow></msub><mo>(</mo><mi>N</mi><mo>)</mo></math></span> of a Sidon system of <em>k</em>-subsets of <span><math><mo>[</mo><mi>N</mi><mo>]</mo></math></span> satisfies <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>k</mi></mrow></msub><mo>(</mo><mi>N</mi><mo>)</mo><mo>≤</mo><mrow><mo>(</mo><mtable><mtr><mtd><mrow><mi>N</mi><mo>−</mo><mn>1</mn></mrow></mtd></mtr><mtr><mtd><mrow><mi>k</mi><mo>−</mo><mn>1</mn></mrow></mtd></mtr></mtable><mo>)</mo></mrow><mo>+</mo><mi>N</mi><mo>−</mo><mi>k</mi></math></span> and the asymptotic lower bound <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>k</mi></mrow></msub><mo>(</mo><mi>N</mi><mo>)</mo><mo>=</mo><msub><mrow><mi>Ω</mi></mrow><mrow><mi>k</mi></mrow></msub><mo>(</mo><msup><mrow><mi>N</mi></mrow><mrow><mi>k</mi><mo>−</mo><mn>1</mn></mrow></msup><mo>)</mo></math></span>. More precise bounds on <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>k</mi></mrow></msub><mo>(</mo><mi>N</mi><mo>)</mo></math></span> are obtained for <span><math><mi>k</mi><mo>≤</mo><mn>3</mn></math></span>. We also obtain the threshold probability for a random system to be Sidon for <span><math><mi>k</mi><mo>=</mo><mn>2</mn></math></span> and 3.</p></div>","PeriodicalId":35408,"journal":{"name":"Electronic Notes in Discrete Mathematics","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.endm.2018.06.004","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Electronic Notes in Discrete Mathematics","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1571065318300957","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Mathematics","Score":null,"Total":0}
引用次数: 0
Abstract
A family of k-subsets of is a Sidon system if the sumsets are pairwise distinct. We show that the largest cardinality of a Sidon system of k-subsets of satisfies and the asymptotic lower bound . More precise bounds on are obtained for . We also obtain the threshold probability for a random system to be Sidon for and 3.
期刊介绍:
Electronic Notes in Discrete Mathematics is a venue for the rapid electronic publication of the proceedings of conferences, of lecture notes, monographs and other similar material for which quick publication is appropriate. Organizers of conferences whose proceedings appear in Electronic Notes in Discrete Mathematics, and authors of other material appearing as a volume in the series are allowed to make hard copies of the relevant volume for limited distribution. For example, conference proceedings may be distributed to participants at the meeting, and lecture notes can be distributed to those taking a course based on the material in the volume.