Article
Keywords:
hypercube; $(0,2)$-graph; rectagraph; 4-cycle; characterization
Summary:
A $(0,2)$-graph is a connected graph, where each pair of vertices has either 0 or 2 common neighbours. These graphs constitute a subclass of $(0,\lambda )$-graphs introduced by Mulder in 1979. A rectagraph, well known in diagram geometry, is a triangle-free $(0,2)$-graph. $(0,2)$-graphs include hypercubes, folded cube graphs and some particular graphs such as icosahedral graph, Shrikhande graph, Klein graph, Gewirtz graph, etc. In this paper, we give some local properties of 4-cycles in $(0,\lambda )$-graphs and more specifically in $(0,2)$-graphs, leading to new characterizations of rectagraphs and hypercubes.
References:
[7] Mulder, H. M.:
The Interval Function of a Graph. Mathematical Centre Tracts 132, Mathematisch Centrum, Amsterdam (1980).
MR 0605838 |
Zbl 0446.05039
[10] Nieminen, J., Peltola, M., Ruotsalainen, P.:
Two characterizations of hypercubes. Electron. J. Comb. (electronic only) 18 (2011), Research Paper 97 10 pages.
MR 2795778 |
Zbl 1217.05195