On the computation of Castelnuovo-Mumford regularity of the Rees algebra and of the fiber ring

摘要

We present algorithms for the computation of the Castelnuovo-Mumford regularity of the Rees algebra and of the fiber ring of equigenerated m-primary ideals in two variables. Applying these algorithms, we find a counter-example to a conjecture of Eisenbud and Ulrich which states that these regularities are equal. (C) 2019 Elsevier B.V. All rights reserved.