Graph Colouring Is Hard on Average for Polynomial Calculus and Nullstellensatz
arXiv:2503.17022
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 ErdÅs-Rényi random graphs, are -colourable. Using the known relation between size and degree for polynomial calculus proofs, this implies strongly exponential lower bounds on proof size.
An extended abstract appeared in FOCS'23