Some degree conditions for 𝒫≥k-factor covered graphs
Guowei Dai, Zan‐Bo Zhang, Yicheng Hang, Xiaoyan Zhang · RAIRO - Operations Research · 2021
A spanning subgraph of a graph G is called a path-factor of G if its each component is a path. A path-factor is called a 𝒫≥k-factor of G if its each component admits at least k vertices, where k ≥ 2. (Zhang and Zhou, Discrete Math. 309 (2009) 2067–2076) defined the concept of 𝒫≥k-factor covered graphs, i.e., G is called a 𝒫≥k-factor covered graph if it has a 𝒫≥k-factor covering e for any e∈ E(G). In this paper, we firstly obtain a minimum degree condition for a planar graph being a 𝒫≥2-factor and 𝒫≥3-factor covered graph, respectively. Secondly, we investigate the relationship between the maximum degree of any pairs of non-adjacent vertices and 𝒫≥k-factor covered graphs, and obtain a sufficient condition for the existence of 𝒫≥2-factor and 𝒫≥3-factor covered graphs, respectively.