{ "id": "1910.00007", "version": "v1", "published": "2019-09-30T06:28:36.000Z", "updated": "2019-09-30T06:28:36.000Z", "title": "On a conjecture of Badakhshian, Katona and Tuza", "authors": [ "Yeshwant Pandit", "S. L. Sravanthi", "Suresh Dara", "S. M. Hegde" ], "categories": [ "math.CO" ], "abstract": "Let ${[n] \\choose k}$ and ${[n] \\choose l}$ $( k > l ) $ where $[n] = \\{1,2,3,...,n\\}$ denote the family of all $k$-element subsets and $l$-element subsets of $[n]$ respectively. Define a bipartite graph $G_{k,l} = ({[n] \\choose k},{[n] \\choose l},E)$ such that two vertices $S\\, \\epsilon \\,{[n] \\choose k} $ and $T\\, \\epsilon \\,{[n] \\choose l} $ are adjacent if and only if $T \\subset S$. In this paper, we disprove the conjecture of Badakhshian, Katona and Tuza for $k= \\lceil \\frac{n}{2} \\rceil +1 $ and $k=n-1$ for $n\\geq 10$ and $n>2$ respectively. Also, we give an upper bound for the domination number of $G_{k,2}$ for $k > \\lceil \\frac{n}{2} \\rceil$.", "revisions": [ { "version": "v1", "updated": "2019-09-30T06:28:36.000Z" } ], "analyses": { "keywords": [ "conjecture", "badakhshian", "element subsets", "bipartite graph", "upper bound" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }