On oriented cycles in randomly perturbed digraphs

Autor: Araujo, Igor, Balogh, József, Krueger, Robert A., Piga, Simón, Treglown, Andrew
Rok vydání: 2022
Předmět:
Druh dokumentu: Working Paper
Popis: In 2003, Bohman, Frieze, and Martin initiated the study of randomly perturbed graphs and digraphs. For digraphs, they showed that for every $\alpha>0$, there exists a constant $C$ such that for every $n$-vertex digraph of minimum semi-degree at least $\alpha n$, if one adds $Cn$ random edges then asymptotically almost surely the resulting digraph contains a consistently oriented Hamilton cycle. We generalize their result, showing that the hypothesis of this theorem actually asymptotically almost surely ensures the existence of every orientation of a cycle of every possible length, simultaneously. Moreover, we prove that we can relax the minimum semi-degree condition to a minimum total degree condition when considering orientations of a cycle that do not contain a large number of vertices of indegree $1$. Our proofs make use of a variant of an absorbing method of Montgomery.
Comment: 24 pages, 7 figures. Author accepted manuscript, to appear in Combinatorics, Probability and Computing
Databáze: arXiv