{ "id": "2006.02841", "version": "v1", "published": "2020-06-04T13:20:19.000Z", "updated": "2020-06-04T13:20:19.000Z", "title": "An inverse formula for the distance matrix of a wheel graph with even number of vertices", "authors": [ "R. Balaji", "R. B. Bapat", "Shivani Goel" ], "categories": [ "math.CO", "math.FA" ], "abstract": "Let $n \\geq 4$ be an even integer and $W_n$ be the wheel graph with $n$ vertices. The distance $d_{ij}$ between any two distinct vertices $i$ and $j$ of $W_n$ is the length of the shortest path connecting $i$ and $j$. Let $D$ be the $n \\times n$ symmetric matrix with diagonal entries equal to zero and off-diagonal entries equal to $d_{ij}$. In this paper, we find a positive semidefinite matrix $\\widetilde{L}$ such that ${\\rm rank}(\\widetilde{L})=n-1$, all row sums of $\\widetilde{L}$ equal to zero and a rank one matrix $ww^T$ such that \\[D^{-1}=-\\frac{1}{2}\\widetilde{L} + \\frac{4}{n-1}ww^T. \\] An interlacing property between the eigenvalues of $D$ and $\\widetilde{L}$ is also proved.", "revisions": [ { "version": "v1", "updated": "2020-06-04T13:20:19.000Z" } ], "analyses": { "subjects": [ "05C50" ], "keywords": [ "wheel graph", "distance matrix", "inverse formula", "off-diagonal entries equal", "shortest path" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }