A Dirac-type theorem for arbitrary Hamiltonian $H$-linked digraphs
Abstract
Given any digraph on vertices, let be the family of all directed paths in , and let be a digraph with the arc set . The digraph is called arbitrary Hamiltonian -linked if for any injective map and any integer set satisfying that for each , there is a map such that for every arc , is a directed path from to of length , and different arcs are mapped into internally vertex-disjoint directed paths in , and . Here, the length of a directed path is defined as the number of its arcs. In this paper, we prove that for any digraph with arcs and , there exists a constant such that if is a digraph of order and minimum in- and out-degree at least , then it is arbitrary Hamiltonian -linked. The lower bound on the minimum in- and out-degree is best possible. We further prove a more general form that allows to be linear in , while imposing some restrictions on the lengths of the subdivided arcs. As corollaries, we solved a conjecture of Wang \cite{Wang} for sufficiently large graphs, and partly answered a problem raised by Pavez-Sign\'{e} \cite{Pavez}.
Keywords
Cite
@article{arxiv.2401.17475,
title = {A Dirac-type theorem for arbitrary Hamiltonian $H$-linked digraphs},
author = {Yangyang Cheng and Zhilan Wang and Jin Yan},
journal= {arXiv preprint arXiv:2401.17475},
year = {2025}
}