The overflow in the Katona Theorem
Combinatorics
2025-06-09 v1
Abstract
Let be integers. We consider families of subsets of an -element set, in which the union of any two members has size at most . One of our results states that for the number of members of size exceeding in is at most . Another result shows that for the number of sets of size at least is at most . Both bounds are best possible and the latter sharpens the classical Katona Theorem. Similar results are proved for the odd case of the Katona Theorem as well.
Keywords
Cite
@article{arxiv.2506.05704,
title = {The overflow in the Katona Theorem},
author = {Peter Frankl and Jian Wang},
journal= {arXiv preprint arXiv:2506.05704},
year = {2025}
}