Color degree and monochromatic degree conditions for short properly colored cycles in edge‐colored graphs

Abstract

AbstractFor an edge‐colored graph, its minimum color degree is defined as the minimum number of colors appearing on the edges incident to a vertex and its maximum monochromatic degree is defined as the maximum number of edges incident to a vertex with a same color. A cycle is called properly colored if every two of its adjacent edges have distinct colors. In this article, we first give a minimum color degree condition for the existence of properly colored cycles, then obtain the minimum color degree condition for an edge‐colored complete graph to contain properly colored triangles. Afterwards, we characterize the structure of an edge‐colored complete bipartite graph without containing properly colored cycles of length 4 and give the minimum color degree and maximum monochromatic degree conditions for an edge‐colored complete bipartite graph to contain properly colored cycles of length 4, and those passing through a given vertex or edge, respectively.