On the arithmetic-geometric index of graphs
| Autor: | Cui, Shu-Yu, Wang, Weifan, Tian, Gui-Xian, Wu, Baoyindureng |
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| Rok vydání: | 2020 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Very recently, the first geometric-arithmetic index $GA$ and arithmetic-geometric index $AG$ were introduced in mathematical chemistry. In the present paper, we first obtain some lower and upper bounds on $AG$ and characterize the extremal graphs. We also establish various relations between $AG$ and other topological indices, such as the first geometric-arithmetic index $GA$, atom-bond-connectivity index $ABC$, symmetric division deg index $SDD$, chromatic number $\chi$ and so on. Finally, we present some sufficient conditions of $GA(G)>GA(G-e)$ or $AG(G)>AG(G-e)$ for an edge $e$ of a graph $G$. In particular, for the first geometric-arithmetic index, we also give a refinement of Bollob\'{a}s-Erd\H{o}s-type theorem obtained in [3]. Comment: 24 pages, 4 figures, 32 conferences |
| Databáze: | arXiv |
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