Rings are $χ$-bounded

Source abstract

We prove that there is a function $f:\mathbb N\to\mathbb N$ such that $χ(Γ(R))\leq f(ω(Γ(R)))$ for the zero-divisor graph of any ring $R$, if the clique number is finite. On the one hand, this consolidates a disproved conjecture of Beck from 1988, claiming $χ(Γ(R))=ω(Γ(R))$ for unital commutative rings. While previous counterexamples satisfy $χ(Γ(R))\leq ω(Γ(R))+2$, we obtain the lower bound $f\geq k^{Ω(\log k)}$ among finite commutative rings. Finally, we show that neither zero-divisor graphs of finite commutative semirings nor those of finite commutative nonassociative rings are $χ$-bounded.