Toughness and \([a, b]\)-factors in Graphs

Renying Chang1, Yan Zhu2, Guizhen Liu3
1School of Mathematics, Linyi University, Linyi, 276005, China
2 Department of Mathematics, East China University of Science and Technology, Shanghai, 200237, China
3School of Mathematics, Shandong University, Jinan, 250100, China

Abstract

In this paper, we consider the relationship between toughness and the existence of \([a, b]\)-factors. We obtain that a graph \(G\) has an \([a, b]\)-factor if \(t(G) \geq {a-1} + \frac{a-1}{b}\) with \(b > a > 1\). Furthermore, it is shown that the result is best possible in some sense.