ملخص: The identification of diametrical vertices in the d-dimensional hypercube (d [ges] 3) leads to a (0, 2)-graph of degree d on 2d-1 vertices and of diameter [left floor] d/2 [right floor] namely the extended odd graph (or Laborde-Mulder graph) for odd values of d, and the half-cube for even values of d. In this paper we prove that the diameter of a (0, 2)-graph of degree d on 2d-1 vertices is at least [left floor] d/2 [right floor], and when d is odd the equality holds if and only if the graph is a Laborde-Mulder graph.

لغة: إنجليزية