The Golod property for Stanley-Reisner rings in varying characteristic

Abstract

We show that the Golod property of a Stanley-Reisner ring can depend on the characteristic of the base field. More precisely, for every finite set $T$ of prime numbers we construct simplicial complexes $\Delta$ and $\Gamma$, such that $\mathbb{K}[\Delta]$ is Golod exactly in the characteristics in $T$ and $\mathbb{K}[\Gamma]$ is Golod exactly in the characteristics not in $T$. Along the way, we show that a one-dimensional simplicial complex is Golod if and only if it is chordal.Comment: 13 pages. Minor corrections, one simplified proof. To appear in J. Pure and applied Al