{ "id": "2010.03219", "version": "v1", "published": "2020-10-07T06:56:56.000Z", "updated": "2020-10-07T06:56:56.000Z", "title": "Excellent graphs with respect to domination: subgraphs induced by minimum dominating sets", "authors": [ "Vladimir Samodivkin" ], "comment": "13 pages, 2 figures", "categories": [ "math.CO" ], "abstract": "A graph $G=(V,E)$ is $\\gamma$-excellent if $V$ is a union of all $\\gamma$-sets of $G$, where $\\gamma$ stands for the domination number. Let $\\mathcal{I}$ be a set of all mutually nonisomorphic graphs and $\\emptyset \\not= \\mathcal{H} \\subsetneq \\mathcal{I}$. In this paper we initiate the study of the $\\mathcal{H}$-$\\gamma$-excellent graphs, which we define as follows. A graph $G$ is $\\mathcal{H}$-$\\gamma$-excellent if the following hold: (i) for every $H \\in \\mathcal{H}$ and for each $x \\in V(G)$ there exists an induced subgraph $H_x$ of $G$ such that $H$ and $H_x$ are isomorphic, $x \\in V(H_x)$ and $V(H_x)$ is a subset of some $\\gamma$-set of $G$, and (ii) the vertex set of every induced subgraph $H$ of $G$, which is isomorphic to some element of $\\mathcal{H}$, is a subset of some $\\gamma$-set of $G$. For each of some well known graphs, including cycles, trees and some cartesian products of two graphs, we describe its largest set $\\mathcal{H} \\subsetneq \\mathcal{I}$ for which the graph is $\\mathcal{H}$-$\\gamma$-excellent. Results on $\\gamma$-excellent regular graphs and a generalized lexicographic product of graphs are presented. Several open problems and questions are posed.", "revisions": [ { "version": "v1", "updated": "2020-10-07T06:56:56.000Z" } ], "analyses": { "subjects": [ "05C69" ], "keywords": [ "minimum dominating sets", "excellent graphs", "induced subgraph", "excellent regular graphs", "open problems" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }