Saved in:
Bibliographic Details
Main Authors: Grill, Karl, Linzmayer, Daniel, Wien, TU
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2403.05674
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910494911102976
author Grill, Karl
Linzmayer, Daniel
Wien, TU
author_facet Grill, Karl
Linzmayer, Daniel
Wien, TU
contents If an $n$-uniform hypergraph can be 2-colored, then it is said to have property B. Erdős (1963) was the first to give lower and upper bounds for the minimal size $m(n)$ of an $n$-uniform hypergraph without property B. His asymptotic upper bound $O(n^22^n)$ still is the best we know, his lower bound $2^{n-1}$ has seen a number of improvements, with the current best $Ω$ $(2^n\sqrt{n/\log(n)})$ established by Radhakrishnan and Srinivasan (2000). Cherkashin and Kozik (2014) provided a simplified proof of this result, using Pluhár's (2009) idea of a random greedy coloring. In the present paper, we use a refined version of this argument to obtain improved lower bounds on $m(n)$ for small values of $n$. We also study $m(n,v)$, the size of the smallest $n$-hypergraph without property B having $v$ vertices.
format Preprint
id arxiv_https___arxiv_org_abs_2403_05674
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Improved Lower Bounds for Property B
Grill, Karl
Linzmayer, Daniel
Wien, TU
Combinatorics
Probability
05C30 (Primary) 05C65 (Secondary)
If an $n$-uniform hypergraph can be 2-colored, then it is said to have property B. Erdős (1963) was the first to give lower and upper bounds for the minimal size $m(n)$ of an $n$-uniform hypergraph without property B. His asymptotic upper bound $O(n^22^n)$ still is the best we know, his lower bound $2^{n-1}$ has seen a number of improvements, with the current best $Ω$ $(2^n\sqrt{n/\log(n)})$ established by Radhakrishnan and Srinivasan (2000). Cherkashin and Kozik (2014) provided a simplified proof of this result, using Pluhár's (2009) idea of a random greedy coloring. In the present paper, we use a refined version of this argument to obtain improved lower bounds on $m(n)$ for small values of $n$. We also study $m(n,v)$, the size of the smallest $n$-hypergraph without property B having $v$ vertices.
title Improved Lower Bounds for Property B
topic Combinatorics
Probability
05C30 (Primary) 05C65 (Secondary)
url https://arxiv.org/abs/2403.05674