{ "id": "2005.01037", "version": "v1", "published": "2020-05-03T10:08:01.000Z", "updated": "2020-05-03T10:08:01.000Z", "title": "On $α$-adjacency energy of graphs and Zagreb index", "authors": [ "S. Pirzada", "Bilal A. Rather", "Hilal A. Ganie", "Rezwan ul Shaban" ], "comment": "17 pages", "categories": [ "math.CO" ], "abstract": "Let $A(G)$ be the adjacency matrix and $D(G)$ be the diagonal matrix of the vertex degrees of a simple connected graph $G$. Nikiforov defined the matrix $A_{\\alpha}(G)$ of the convex combinations of $D(G)$ and $A(G)$ as $A_{\\alpha}(G)=\\alpha D(G)+(1-\\alpha)A(G)$, for $0\\leq \\alpha\\leq 1$. If $ \\rho_{1}\\geq \\rho_{2}\\geq \\dots \\geq \\rho_{n}$ are the eigenvalues of $A_{\\alpha}(G)$ (which we call $\\alpha$-adjacency eigenvalues of $G$), the $ \\alpha $-adjacency energy of $G$ is defined as $E^{A_{\\alpha}}(G)=\\sum_{i=1}^{n}\\left|\\rho_i-\\frac{2\\alpha m}{n}\\right|$, where $n$ is the order and $m$ is the size of $G$. We obtain the upper and lower bounds for $E^{A_{\\alpha}}(G) $ in terms of order $n$, size $m$ and Zagreb index $Zg(G)$ associated to the structure of $G$. Further, we characterize the extremal graphs attaining these bounds.", "revisions": [ { "version": "v1", "updated": "2020-05-03T10:08:01.000Z" } ], "analyses": { "subjects": [ "05C50", "05C12", "15A18" ], "keywords": [ "adjacency energy", "zagreb index", "extremal graphs", "diagonal matrix", "vertex degrees" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }