On Roberts rings

Abstract

In 1985, P. C. Roberts [{14}] proved the vanishing theorem of intersection multiplicities for a local ring that satisfies τ_A/S([A])=[Spec A]_dimA, where τ_A/S is the Riemann-Roch map for Spec A with regular base scheme Spec S. We refer such rings as Roberts rings. For rings of positive characteristic, we can characterize Roberts rings by the Frobenius maps. For rings with field of fractions of characteristic 0, we can characterize Roberts rings by some Galois extensions. We shall give basic properties and examples of Roberts rings in the paper.