A comment on Intersecting Families of Permutations

Yuval Filmus

A comment on Intersecting Families of Permutations

Combinatorics 2017-07-03 v1

Authors: Yuval Filmus

Abstract

Ellis, Friedgut and Pilpel proved that for large enough $n$ , a $t$ -intersecting family of permutations contains at most $(n-t)!$ permutations. Their main theorem also states that equality holds only for $t$ -cosets. We show that their proof of the characterization of extremal families is wrong. However, the characterization follows from a paper of Ellis, as mentioned already by Ellis, Friedgut and Pilpel.

Keywords

intersecting families permutations t-intersecting family t-cosets extremal families characterization combinatorics

Cite

@article{arxiv.1706.10146,
  title  = {A comment on Intersecting Families of Permutations},
  author = {Yuval Filmus},
  journal= {arXiv preprint arXiv:1706.10146},
  year   = {2017}
}

Comments

6 pages; a comment on arXiv:1011.3342

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