A New Bound on Maximum Genus of Simple Graphs

Shengxiang Lv1, Yanpei Liu2
1Department of Mathematics, Hunan University of Science and Technology, Hunan Xiangtan 411201, China
2Department of Mathematics, BeiJing Jiaotong University, Beijing 100044, China

Abstract

Let \(G\) be a connected simple graph with girth \(g\) and minimal degree \(\delta \geq 3\). If \(G\) is not up-embeddable, then, when \(G\) is 1-edge connected,

\[\gamma_M(G) \geq \frac{D_1(\delta,g)-2}{2D_1(\delta,g)-1}\beta(G)+ \frac{D_1(\delta,g)+1}{2D_1(\delta,g)-1}.\]

When \(G\) is \(k\)(\(k = 2, 3\))-edge connected ,

\[\gamma_M(G) \geq \frac{D_k(\delta,g)-1}{2D_k(\delta,g)}\beta(G)+ \frac{D_k(\delta,g)+1}{2D_k(\delta,g)}.\]

The functions \(D_k(\delta, g)\) (\(k = 1, 2, 3\)) are increasing functions on \(\delta\) and \(g\).