English

Single conflict coloring, adaptable choosability and separation choosability

Combinatorics 2025-09-18 v1

Abstract

We study relations between three interrelated notions of graph (list) coloring: single conflict coloring, adapted list coloring and choosability with separation (with 11 overlapping color between lists of adjacent vertices), and their respective invariants single conflict chromatic number χ\chi_{\nleftrightarrow}, adaptable choosability chadch_{ad} and separation choosability chsepch_{sep}. We investigate graphs with small values of these invariants, and construct explicit families of graphs GG with χ(G)=chad(G)>chsep(G)\chi_{\nleftrightarrow}(G) = ch_{ad}(G) > ch_{sep}(G), as well as where all three invariants are equal. Furthermore, we consider planar graphs and investigate for which triples (a,b,c)(a,b,c), there is a planar graph GG with (chsep(G),chad(G),χ(G))=(a,b,c)(ch_{sep}(G), ch_{ad}(G), \chi_{\nleftrightarrow}(G)) = (a,b,c). Throughout the paper we pose many questions on these graph coloring parameters, and discuss connections to related coloring invariants such as adapted coloring.

Keywords

Cite

@article{arxiv.2509.13913,
  title  = {Single conflict coloring, adaptable choosability and separation choosability},
  author = {Carl Johan Casselgren and Kalle Eriksson},
  journal= {arXiv preprint arXiv:2509.13913},
  year   = {2025}
}
R2 v1 2026-07-01T05:41:46.978Z