English

Maximum shattering

Combinatorics 2024-10-29 v2

Abstract

A family F\mathcal{F} of subsets of [n]={1,2,,n}[n]=\{1,2,\ldots,n\} shatters a set A[n]A \subseteq [n] if for every AAA' \subseteq A there is an FFF \in \mathcal{F} such that FA=AF \cap A=A'. We develop a framework to analyze f(n,k,d)f(n,k,d), the maximum possible number of subsets of [n][n] of size dd that can be shattered by a family of size kk. Among other results, we determine f(n,k,d)f(n,k,d) exactly for d2d \leq 2 and show that if dd and nn grow, with both dd and ndn-d tending to infinity, then, for any kk satisfying 2dk(1+o(1))2d2^d \leq k \leq (1+o(1))2^d, we have f(n,k,d)=(1+o(1))c(nd)f(n,k,d)=(1+o(1))c\binom{n}{d}, where cc, roughly 0.2890.289, is the probability that a large square matrix over F2\mathbb{F}_2 is invertible. This latter result extends work of Das and M\'esz\'aros. As an application, we improve bounds for the existence of covering arrays for certain alphabet sizes.

Keywords

Cite

@article{arxiv.2409.12945,
  title  = {Maximum shattering},
  author = {Noga Alon and Varun Sivashankar and Daniel G. Zhu},
  journal= {arXiv preprint arXiv:2409.12945},
  year   = {2024}
}

Comments

15 pages, 2 figures