English

Transversal and Hamiltonicity in a bipartite graph collection

Combinatorics 2026-03-11 v2

Abstract

Let G={G1,,Gs}\mathbf{G}=\{G_1,\dots,G_{s}\} be a collection of ss bipartite graphs with the same bipartition V=(X,Y)V=(X,Y). For a path PP with V(P)=VV(P)=V and E(P)=s|E(P)|=s, if there exists an injection ϕ\phi: E(P)[s]E(P)\rightarrow [s] such that eE(Gϕ(e))e\in E(G_{\phi(e)}) for each eE(P)e\in E(P), then we say that the Hamiltonian path PP is a G\mathbf{G}-transversal. A bipartite graph collection G\mathbf{G} is called Hamiltonian connected if for any two vertices xXx\in X and yYy\in Y, there exists a G\mathbf{G}-transversal isomorphic to a Hamiltonian path between xx and yy. In this paper, we give the minimum degree conditions that ensure the existence of a G\mathbf{G}-transversal isomorphic to a Hamiltonian path and the Hamiltonian connectivity of a balanced bipartite graph collection G\mathbf{G}, which improve the results of [Hu, Li, Li and Xu, Discrete Math., 2024]. Moreover, we also provide a minimum degree condition that guarantees a nearly balanced bipartite graph collection G\mathbf{G} contains a G\mathbf{G}-transversal isomorphic to a Hamiltonian path.

Keywords

Cite

@article{arxiv.2601.17758,
  title  = {Transversal and Hamiltonicity in a bipartite graph collection},
  author = {Menghan Ma and Lihua You and Xiaoxue Zhang},
  journal= {arXiv preprint arXiv:2601.17758},
  year   = {2026}
}