On the power graphs of finite groups and Hamilton cycle

Document Type : Research Paper

Authors

1 Faculty of Sciences, University of Zabol, Zabol, Iran.

2 Department of Mathematics, Payame Noor University, Tehran, Iran.

3 University of Gonabad, Gonabad, Iran.

Abstract

The power graph $\mathcal{P}(G)$ of a finite group $G$ is a graph whose vertex set is the group $G$ and distinct elements $x,y\in G$ are adjacent if one is a power of the other, that is, $x$ and $y$ are adjacent if $x\in \langle y\rangle$ or $y \in \langle x\rangle$. In this paper, we study existence of the Hamilton cycle in the power graph of some finite nilpotent groups $G$ with a cyclic subgroup as direct factor when $G$ is written as direct product Sylow $p$-subgroups. For this purpose we use of cartesian product a spanning tree and a cycle. Finally, we determined values of $n$ such that $\mathcal{P}(U_n)$ is Hamiltonian, where $U_n$ is a group consist of all positive integers less than $n$ and relatively prime to $n$ under multiplication modulo $n$.
 

Keywords


[1] V. Batagelj and T. Pisanski, Hamiltonian cycles in the cartesain product of a tree and a cycle, Discrete Math., 38 (1982) 311-312.
[2] J. A. Bondy and U. S. R. Murty, Graph Theory, Springer, New York, 2008.
[3] I. Chakrabarty, S. Ghosh and M. K. Sen, Undirected power graphs of semigroups, Semigr. Forum, 78 No. 3 (2009) 410-426.
[4] A. Doostabadi and M. Farrokhi D. G., On the connectivity of proper power graphs of finite groups, Commun. Algebra, 43 No. 10 (2015) 4305-4319.
[5] A. V. Kelarev and S. J. Quinn, A combinatorial property and power graphs of groups, Contrib. General Algebra, 12 No. 58 (2000) 229-235.
[6] A. V. Kelarev and S. J. Quinn, Directed graph and combinatorial properties of semigroups, J. Algebra, 251 No. 1 (2002) 16-26.