English

Fan's condition for completely independent spanning trees

Combinatorics 2025-02-18 v1

Abstract

Spanning trees T1,T2,,TkT_1,T_2, \dots,T_k of GG are kk completely independent spanning trees if, for any two vertices u,vV(G)u,v\in V(G), the paths from uu to vv in these kk trees are pairwise edge-disjoint and internal vertex-disjoint. Hasunuma proved that determining whether a graph contains kk completely independent spanning trees is NP-complete, even for k=2k = 2. Araki posed the question of whether certain known sufficient conditions for hamiltonian cycles are also also guarantee two completely independent spanning trees? In this paper, we affirmatively answer this question for the Fan-type condition. Precisely, we proved that if GG is a connected graph such that each pair of vertices at distance 2 has degree sum at least V(G)|V(G)|, then GG has two completely independent spanning trees.

Keywords

Cite

@article{arxiv.2502.11522,
  title  = {Fan's condition for completely independent spanning trees},
  author = {Jie Ma and Junqing Cai},
  journal= {arXiv preprint arXiv:2502.11522},
  year   = {2025}
}
R2 v1 2026-06-28T21:46:44.784Z