English

Counting induced subgraphs with the Kromatic symmetric function

Combinatorics 2025-02-21 v3

Abstract

The chromatic symmetric function XGX_G is a sum of monomials corresponding to proper vertex colorings of a graph GG. Crew, Pechenik, and Spirkl (2023) recently introduced a KK-theoretic analogue XG\overline{X}_G called the Kromatic symmetric function, where each vertex is instead assigned a nonempty set of colors such that adjacent vertices have nonoverlapping color sets. XGX_G does not distinguish all graphs, but a longstanding open question is whether it distinguishes all trees. We conjecture that XG\overline{X}_G does distinguish all graphs. As evidence towards this conjecture, we show that XG\overline{X}_G determines the number of copies in GG of certain induced subgraphs on 4 and 5 vertices as well as the number of induced subgraphs isomorphic to each graph consisting of a star plus some number of isolated vertices.

Keywords

Cite

@article{arxiv.2403.15929,
  title  = {Counting induced subgraphs with the Kromatic symmetric function},
  author = {Laura Pierson},
  journal= {arXiv preprint arXiv:2403.15929},
  year   = {2025}
}

Comments

12 pages, comments welcome! v2: corrected a small error with one of the order 5 graphs

R2 v1 2026-06-28T15:31:13.293Z