We study the Castelnuovo-Mumford regularity of the module of Koszul cycles Zt(I,M) of a homogeneous ideal I in a polynomial ring S with respect to a graded module M in the homological position t ∈ N. Under mild assumptions on the base field we prove that reg Zt(I,S) is a subadditive function of t when dim S/I = 0. For Borel-fixed ideals I, J we prove that reg Zt(I,S/J) ≤ t(1 + reg I) + regS/J, a result already announced by Bruns, Conca and Römer.
- Castelnuovo-Mumford regularity
- Koszul cycles
- Koszul homology
ASJC Scopus subject areas
- Applied Mathematics