$3$-setwise intersecting families of the symmetric group
Abstract
Given two positive integers and , the permutations are -setwise intersecting if they agree (setwise) on a -subset of . A family is -setwise intersecting if any two permutations of are -setwise intersecting. Ellis [Journal of Combinatorial Theory, Series A, 119(4), 825--849, 2012] conjectured that if and is a -setwise intersecting family, then and equality holds only if is a coset of a setwise stablizer of a -subset of . In this paper, we prove that if and is -setwise intersecting, then . Moreover, we prove that the characteristic vector of a -setwise intersecting family of maximum size lies in the sum of the eigenspaces induced by the permutation module of acting on the -subsets of .
Keywords
Cite
@article{arxiv.2010.00229,
title = {$3$-setwise intersecting families of the symmetric group},
author = {Angelot Behajaina and Roghayeh Maleki and Aina Toky Rasoamanana and A. Sarobidy Razafimahatratra},
journal= {arXiv preprint arXiv:2010.00229},
year = {2021}
}
Comments
19 pages, a link to our code was added, typos and grammar mistakes were fixed