{ "id": "1910.10876", "version": "v1", "published": "2019-10-24T01:47:53.000Z", "updated": "2019-10-24T01:47:53.000Z", "title": "The asymptotic behavior of the covering number of a graph on two layers of the Boolean lattice", "authors": [ "József Balogh", "William Linz" ], "categories": [ "math.CO" ], "abstract": "Let $n > k > \\ell \\ge 1$ be positive integers, and define a bipartite graph $G_{k, \\ell}=(V, E)$ by $V(G_{k, \\ell})=(\\binom{[n]}{k}, \\binom{[n]}{\\ell})$ and $(A, B) \\in E(G_{k, \\ell})$ if and only if $A \\in \\binom{[n]}{\\ell}$, $B\\in \\binom{[n]}{k}$, and $A\\subset B$. We confirm a conjecture of Badakhshian, Katona and Tuza for the two-sided covering number $\\gamma(G_{k, 2})$, for fixed $k$ and $n\\rightarrow\\infty$. Additionally, we prove a general lower bound for $\\gamma(G_{k, \\ell})$, with $k$ and $\\ell$ fixed and $n\\rightarrow \\infty$. Our proof uses the graph removal lemma and a Frankl-R\\\"odl nibble type theorem of Pippenger.", "revisions": [ { "version": "v1", "updated": "2019-10-24T01:47:53.000Z" } ], "analyses": { "keywords": [ "asymptotic behavior", "boolean lattice", "general lower bound", "graph removal lemma", "nibble type theorem" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }