Castelnuovo-Mumford regularity of Ext modules and homological degree
Commutative Algebra
2009-03-27 v1 Algebraic Geometry
Abstract
Bounds for the Castelnuovo-Mumford regularity of Ext modules, over a polynomial ring over a field, are given in terms of the initial degrees, Castelnuovo-Mumford regularities and number of generators of the two graded modules involved. These general bounds are refined in the case the second module is the ring. Other estimates, for instance on the size of graded pieces of these modules, are given. We also derive a bound on the homological degree in terms of the Castelnuovo-Mumford regularity. This answers positively a question raised by Vasconcelos.
Keywords
Cite
@article{arxiv.0903.4535,
title = {Castelnuovo-Mumford regularity of Ext modules and homological degree},
author = {Marc Chardin and Dao Thanh Ha and Le Tuan Hoa},
journal= {arXiv preprint arXiv:0903.4535},
year = {2009}
}