{ "id": "2305.05878", "version": "v1", "published": "2023-05-10T03:52:04.000Z", "updated": "2023-05-10T03:52:04.000Z", "title": "On Zagreb indices of graphs", "authors": [ "Batmend Horoldagva", "Kinkar Chandra Das" ], "categories": [ "math.CO" ], "abstract": "Let ${\\mathcal G}_n$ be the set of class of graphs of order $n$. The first Zagreb index $M_1(G)$ is equal to the sum of squares of the degrees of the vertices, and the second Zagreb index $M_2(G)$ is equal to the sum of the products of the degrees of pairs of adjacent vertices of the underlying molecular graph $G$. The three set of graphs are as follows: \\begin{eqnarray*} &&A=\\left\\{G\\in {\\mathcal G}_n:\\,\\frac{M_1(G)}{n}>\\frac{M_2(G)}{m}\\right\\},~B=\\left\\{G\\in {\\mathcal G}_n:\\,\\frac{M_1(G)}{n}=\\frac{M_2(G)}{m}\\right\\} \\mbox{ and }&& &&~~~~~~~~~~~~~~~~~~~~~~~~~C=\\left\\{G\\in {\\mathcal G}_n:\\,\\frac{M_1(G)}{n}<\\frac{M_2(G)}{m}\\right\\}. \\end{eqnarray*} In this paper we prove that $|A|+|B|<|C|$. Finally, we give a conjecture $|A|<|B|$.", "revisions": [ { "version": "v1", "updated": "2023-05-10T03:52:04.000Z" } ], "analyses": { "subjects": [ "05C07", "05C35", "05C90" ], "keywords": [ "first zagreb index", "second zagreb index", "molecular graph", "adjacent vertices" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }