{ "id": "1612.00007", "version": "v1", "published": "2016-11-30T21:00:00.000Z", "updated": "2016-11-30T21:00:00.000Z", "title": "On the number of maximum independent sets in Doob graphs", "authors": [ "Denis Krotov" ], "comment": "5 pages, 2 figures", "journal": "Sib. Elektron. Mat. Izv. (Siberian Electronic Mathematical Reports) 12, 2015, 508-512", "doi": "10.17377/semi.2015.12.043", "categories": [ "math.CO", "cs.DM" ], "abstract": "The Doob graph $D(m,n)$ is a distance-regular graph with the same parameters as the Hamming graph $H(2m+n,4)$. The maximum independent sets in the Doob graphs are analogs of the distance-$2$ MDS codes in the Hamming graphs. We prove that the logarithm of the number of the maximum independent sets in $D(m,n)$ grows as $2^{2m+n-1}(1+o(1))$. The main tool for the upper estimation is constructing an injective map from the class of maximum independent sets in $D(m,n)$ to the class of distance-$2$ MDS codes in $H(2m+n,4)$.", "revisions": [ { "version": "v1", "updated": "2016-11-30T21:00:00.000Z" } ], "analyses": { "subjects": [ "05B15", "05E30" ], "keywords": [ "maximum independent sets", "doob graph", "mds codes", "hamming graph", "main tool" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 5, "language": "en", "license": "arXiv", "status": "editable" } } }