A bound on the Hartshorne-Speiser-Lyubeznik number of semigroup rings

Abstract

In this paper we prove an explicit, computable upper bound on the Hartshorne-Speiser-Lyubeznik number of the local cohomology of a pointed, affine semigroup ring over a perfect field of positive characteristic. This bound depends only on the characteristic of the ring and properties of the semigroup.

arXiv comment18 pages, 1 figure