{ "id": "2301.03389", "version": "v1", "published": "2022-11-02T03:05:40.000Z", "updated": "2022-11-02T03:05:40.000Z", "title": "On the $α$-index of minimally 2-connected graphs with given order or size", "authors": [ "Jiayu Lou", "Ligong Wang", "Ming Yuan" ], "comment": "15 pages, 1 figure", "categories": [ "math.CO" ], "abstract": "For any real $\\alpha \\in [0,1]$, Nikiforov defined the $A_\\alpha$-matrix of a graph $G$ as $A_\\alpha(G)=\\alpha D(G)+(1-\\alpha)A(G)$, where $A(G)$ and $D(G)$ are the adjacency matrix and the diagonal matrix of vertex degrees of $G$, respectively. The largest eigenvalue of $A_\\alpha(G)$ is called the $\\alpha$-index or the $A_\\alpha$-spectral radius of $G$. A graph is minimally $k$-connected if it is $k$-connected and deleting any arbitrary chosen edge always leaves a graph which is not $k$-connected. In this paper, we characterize the extremal graphs with the maximum $\\alpha$-index for $\\alpha \\in [\\frac{1}{2},1)$ among all minimally 2-connected graphs with given order or size, respectively.", "revisions": [ { "version": "v1", "updated": "2022-11-02T03:05:40.000Z" } ], "analyses": { "subjects": [ "05C50", "05C40", "05C35" ], "keywords": [ "arbitrary chosen edge", "extremal graphs", "adjacency matrix", "diagonal matrix", "spectral radius" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }