文摘
In a search for triangle-free graphs with arbitrarily large chromatic number, Mycielski developed a graph transformation that transforms a graph G into a new graph?μ(G), which is called the Mycielskian of G. A generalisation of this transformation is the generalised Mycielskian?μ m (G), m a positive integer. This paper investigates the vertex-connectivity κ and arc-connectivity κ-of the generalised Mycielskian of strongly connected digraphs D. We show that κ (μ m (D)) = min{δ(μ m (D)), (m?+?1)κ (D) + 1} and κ-(μ m (D)) = δ(μ m (D)) where δ(μ m (D)) denotes the minimum degree of the generalised Mycielisian?μ m (D). This turns out to be a generalisation of the results due to Guo and Guo (Appl. Math. Lett. 22:1622-625, 2009).