An improved lower bound for the union-closed set conjecture
Combinatorics
2023-06-21 v3
Abstract
Gilmer has recently shown that in any nonempty union-closed family of subsets of a finite set, there exists an element contained in at least a proportion of the sets of . We improve the proportion from to in this result. An improvement to would be the Frankl union-closed set conjecture. We follow Gilmer's method, replacing one key estimate by a sharp estimate. We then suggest a new addition to this method and sketch a proof that it can obtain a constant strictly greater than . We also disprove a conjecture of Gilmer that would have implied the union-closed set conjecture.
Cite
@article{arxiv.2211.11504,
title = {An improved lower bound for the union-closed set conjecture},
author = {Will Sawin},
journal= {arXiv preprint arXiv:2211.11504},
year = {2023}
}
Comments
9 pages