On First Zagreb index, \({\tau}\)-path-coverable and \({\tau}\)-edge-Hamiltonian graphs

Mingqiang An1, Runli Tian2, Huiya Yan3
1College of Science, Tianjin University of Science and Technology, Tianjin, 300457, P.R. China
2School of Software Engineering, Changsha Institute of Technology, Changsha, 410200, P.R. China
3Mathematics and Statistics Department, University of Wisconsin-La Crosse, La Crosse, WI 54601, USA

Abstract

Given a connected graph \(H\), its first Zagreb index \(M_{1}(H)\) is equal to the sum of squares of the degrees of all vertices in \(H\). In this paper, we give a best possible lower bound on \(M_{1}(H)\) that guarantees \(H\) is \(\tau\)-path-coverable and \(\tau\)-edge-Hamiltonian, respectively. Our research supplies a continuation of the results presented by Feng et al. (2017).

Keywords: Zagreb index, \(\tau\)-path-coverable, \(\tau\)-edge-Hamiltonian