{ "id": "2306.15301", "version": "v1", "published": "2023-06-27T08:39:47.000Z", "updated": "2023-06-27T08:39:47.000Z", "title": "Connectivity of 2-distance graphs", "authors": [ "S. H. Jafari", "S. R. Musawi" ], "comment": "7 pages, 6 figures", "categories": [ "math.CO" ], "abstract": "For a simple graph $G$, the $2$-distance graph, $D_2(G)$, is a graph with the vertex set $V(G)$ and two vertices are adjacent if and only if their distance is $2$ in the graph $G$. In this paper, we characterize all graphs with connected 2-distance graph. For graphs with diameter 2, we prove that $D_2(G)$ is connected if and only if $G$ has no spanning complete bipartite subgraphs. For graphs with a diameter greater than 2, we define a maximal Fine set and by contracting $G$ on these subsets, we get a new graph $\\hat G$ such that $D_2(G)$ is connected if and only if $D_2(\\hat G)$ is connected. Especially, $D_2(G)$ is disconnected if and only if $\\hat G$ is bipartite.", "revisions": [ { "version": "v1", "updated": "2023-06-27T08:39:47.000Z" } ], "analyses": { "subjects": [ "05C12", "05C15", "G.2.2" ], "keywords": [ "connectivity", "spanning complete bipartite subgraphs", "maximal fine set", "vertex set", "simple graph" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable" } } }