14-vertex counterexample with list chromatic number three
Model / AI: ChatGPT 6 Astra Ultra
Jonathan A. Noel disproves the 2000 conjecture of Albertson, Grossman, and Haas by exhibiting a 14-vertex graph of list chromatic number 3 with a 2-list assignment in which no proper colouring can colour more than 9 vertices, strictly below the conjectured bound of 14*(2/3) ≈ 9.33 vertices. The author explicitly credits ChatGPT 6 Astra Ultra with discovering and verifying the counterexample graph.
Source read 2026-10-08. Read the arXiv v1 paper, list assignment tables, and AI-attribution note. The graph's independence number and list coloring bounds were not recomputed.