与第5号掩体相交的家族

IF 0.7 3区 数学 Q2 MATHEMATICS
Peter Frankl , Jian Wang
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引用次数: 0

摘要

如果族F∧([n]k)中的任意两个成员有非空相交,则称其为相交族。F的覆盖数定义为对所有F∈F存在T∧{1,2,…,n}满足|T|=p且T∩F≠∅的最小整数p。定义m(n,k,p)为覆盖数至少为p的相交族F ([n]k)的最大值。m(n,k,p)的值仅在p=1,2,3,4时已知。大约三十年前,m(n,k,5)由第一作者Ota和Tokushige渐近确定。在本文中,我们确定了k≥69和n≥5k6时m(n,k,5)。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Intersecting families with covering number five
A family F([n]k) is called intersecting if any two members of it have non-empty intersection. The covering number of F is defined as the minimum integer p such that there exists T{1,2,,n} satisfying |T|=p and TF for all FF. Define m(n,k,p) as the maximum size of an intersecting family F([n]k) with covering number at least p. The value of m(n,k,p) is only known for p=1,2,3,4. About thirty years ago, m(n,k,5) was determined asymptotically by the first author, Ota and Tokushige. In the present paper, we determine m(n,k,5) for k69 and n5k6.
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来源期刊
Discrete Mathematics
Discrete Mathematics 数学-数学
CiteScore
1.50
自引率
12.50%
发文量
424
审稿时长
6 months
期刊介绍: Discrete Mathematics provides a common forum for significant research in many areas of discrete mathematics and combinatorics. Among the fields covered by Discrete Mathematics are graph and hypergraph theory, enumeration, coding theory, block designs, the combinatorics of partially ordered sets, extremal set theory, matroid theory, algebraic combinatorics, discrete geometry, matrices, and discrete probability theory. Items in the journal include research articles (Contributions or Notes, depending on length) and survey/expository articles (Perspectives). Efforts are made to process the submission of Notes (short articles) quickly. The Perspectives section features expository articles accessible to a broad audience that cast new light or present unifying points of view on well-known or insufficiently-known topics.
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