PreprintCC BY 4.0arXiv
Acyclic Dichromatic Number of Tournaments: these are the Champions
Abstract
The acyclic dichromatic number of an oriented graph is the minimum size of a vertex-partition such that the digraphs induced by any single part are acyclic, and the oriented bipartite graphs between any two parts are acyclic too. We characterize the subtournaments that must appear in every tournament with sufficiently large acyclic dichromatic number, thereby confirming a conjecture of Bang-Jensen, Picasarri-Arrieta, and Yeo and prove that acyclic dichromatic number satisfies a local to global property.
Related
- Digraphs of Large Girth and Dichromatic Number in Tournaments with Large Dichromatic Number
- Fractional Dichromatic Number and Domination in Tournaments
- Cayley Tournaments Simultaneously Critical for the Clique and Dichromatic Numbers
- Acyclic Dicolourings of Oriented Graphs: Paths, Random Tournaments, and Critical Orders
- Every tournament of dichromatic number 10 k2 has a vertex whose out-neighborhood has dichromatic number more than k
BibTeX
@misc{aboulker2026acyclic,
title = {{Acyclic Dichromatic Number of Tournaments: these are the Champions}},
author = {Pierre Aboulker and Pierre Charbit and Samuel Coulomb and Kathryn Nurse and Lucas Picasarri-Arrieta},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2607.14694},
eprint = {2607.14694},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.14694},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Acyclic Dichromatic Number of Tournaments: these are the Champions
AU - Pierre Aboulker
AU - Pierre Charbit
AU - Samuel Coulomb
AU - Kathryn Nurse
AU - Lucas Picasarri-Arrieta
PY - 2026
DA - 2026/10/12
PB - arXiv
DO - 10.48550/arxiv.2607.14694
UR - https://arxiv.org/abs/2607.14694
AB - The acyclic dichromatic number of an oriented graph is the minimum size of a vertex-partition such that the digraphs induced by any single part are acyclic, and the oriented bipartite graphs between any two parts are acyclic too. We characterize the subtournaments that must appear in every tournament with sufficiently large acyclic dichromatic number, thereby confirming a conjecture of Bang-Jensen, Picasarri-Arrieta, and Yeo and prove that acyclic dichromatic number satisfies a local to global property.
ER -