English

Graph Colouring Is Hard on Average for Polynomial Calculus and Nullstellensatz

Computational Complexity 2025-03-24 v1

Abstract

We prove that polynomial calculus (and hence also Nullstellensatz) over any field requires linear degree to refute that sparse random regular graphs, as well as sparse Erd\H{o}s-R\'{e}nyi random graphs, are 33-colourable. Using the known relation between size and degree for polynomial calculus proofs, this implies strongly exponential lower bounds on proof size.

Keywords

Cite

@article{arxiv.2503.17022,
  title  = {Graph Colouring Is Hard on Average for Polynomial Calculus and Nullstellensatz},
  author = {Jonas Conneryd and Susanna F. de Rezende and Jakob Nordström and Shuo Pang and Kilian Risse},
  journal= {arXiv preprint arXiv:2503.17022},
  year   = {2025}
}

Comments

An extended abstract appeared in FOCS'23

R2 v1 2026-06-28T22:29:33.596Z