The maximum number of disjoint pairs in a family of subsets
Author(s) -
Noga Alon,
Péter Frankl
Publication year - 1985
Publication title -
graphs and combinatorics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.59
H-Index - 40
eISSN - 1435-5914
pISSN - 0911-0119
DOI - 10.1007/bf02582924
Subject(s) - disjoint sets , combinatorics , mathematics , conjecture , family of sets , bounded function , element (criminal law) , set (abstract data type) , discrete mathematics , computer science , mathematical analysis , political science , law , programming language
Let ℱ be a family of 2 n+1 subsets of a 2n-element set. Then the number of disjoint pairs in ℱ is bounded by (1+o(1))22n . This proves an old conjecture of Erdös. Let ℱ be a family of 21/(k+1)+δ)n subsets of ann-element set. Then the number of containments in ℱ is bounded by (1-1/k+o(1))(2|ℱ|). This verifies a conjecture of Daykin and Erdös. A similar Erdös-Stone type result is proved for the maximum number of disjoint pairs in a family of subsets.
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