0 KB255 KB18 KB200820252013Das, Kinkar ChandraGraovac, AnteLee, Dae-Wonštevilka:1letnik:6str. 117-125COBISSID:16470873ISSN:1855-3966URN:URN:NBN:SI:doc-SKSZN34BenDruštvo matematikov, fizikov in astronomov SlovenijeArs mathematica contemporaneadiametereccentricityfirst Zagreb eccentricity indexgraphsecond Zagreb eccentricity indexSome properties of the Zagreb eccentricity indices|The concept of Zagreb eccentricity (?$E_1$? and ?$E_2$?) indices was introduced in the chemical graph theory very recently. The first Zagreb eccentricity ?($E_1$)? and the second Zagreb eccentricity ?($E_2$)? indices of a graph ?$G$? are defined as ?$$E_1 = E_1(G) = \sum_{v_i \in V(G)} e_i^2$$? and ?$$E_2 = E_2(G) = \sum_{v_i v_j \in E(G)} e_i \cdot e_j \;,$$? where ?$E(G)$? is the edge set and ?$e_i$? is the eccentricity of the vertex ?$v_i$? in ?$G$?. In this paper we give some lower and upper bounds on the first Zagreb eccentricity and the second Zagreb eccentricity indices of trees and graphs, and also characterize the extremal graphsTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza na Primorskem, Fakulteta za naravoslovje, matematiko in informacijske tehnologije