PreprintCC BY 4.0arXiv
A note on the list chromatic number of two matroids
Abstract
We study list coloring of common independent sets of two matroids. We construct a graphic matroid M1 and a partition matroid M2 with common chromatic number two and common list chromatic number three, showing that the two parameters need not be equal. This resolves a question raised by Király, later stated as a conjecture by Aharoni, Berger, Guo, and Kotlar. We also show that if two strongly base-orderable matroids are each $2$-colorable, then their intersection is $2$-list-colorable.
Related
BibTeX
@misc{garami2026note,
title = {{A note on the list chromatic number of two matroids}},
author = {Bence Garami},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.07318},
eprint = {2610.07318},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.07318},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - A note on the list chromatic number of two matroids
AU - Bence Garami
PY - 2026
DA - 2026/10/05
PB - arXiv
DO - 10.48550/arxiv.2610.07318
UR - https://arxiv.org/abs/2610.07318
AB - We study list coloring of common independent sets of two matroids. We construct a graphic matroid M_1 and a partition matroid M_2 with common chromatic number two and common list chromatic number three, showing that the two parameters need not be equal. This resolves a question raised by Király, later stated as a conjecture by Aharoni, Berger, Guo, and Kotlar. We also show that if two strongly base-orderable matroids are each $2$-colorable, then their intersection is $2$-list-colorable.
ER -