English

Degree-truncated choosability of planar graphs

Combinatorics 2025-07-15 v2

Abstract

Assume GG is a graph and kk is a positive integer. Let f:V(G)Nf:V(G)\to \mathbb{N} be defined as f(v)=min{k,dG(v)}f(v)=\min\{k,d_G(v)\}. If GG is ff-choosable, then we say GG is degree-truncated kk-choosable. Answering a question of Richter, it was proved in [Zhou,Zhu,Zhu, Degree-truncated choice number of graphs, arXiv:2308.15853] that there exists a 3-connected non-complete planar graph that is not degree-truncated 7-choosable, and every 3-connected non-complete planar graph is degree-truncated 16-choosable. This paper improves the bounds, and proves that there exists a 3-connected non-complete planar graph that is not degree-truncated 8-choosable, and that every 3-connected non-complete planar graph is degree-truncated 1212-choosable.

Keywords

Cite

@article{arxiv.2406.06035,
  title  = {Degree-truncated choosability of planar graphs},
  author = {Yiting Jiang and Huijuan Xu and Xinbo Xu and Xuding Zhu},
  journal= {arXiv preprint arXiv:2406.06035},
  year   = {2025}
}

Comments

19 pages, 1 figure

R2 v1 2026-06-28T16:59:12.100Z