Mathematics – Commutative Algebra
Scientific paper
2005-08-30
Mathematics
Commutative Algebra
29 pages; final version (minor changes from version 1), to appear in Nagoya Math. J
Scientific paper
Let R=k[x_1,...,x_n] be a polynomial ring over a field k. Let J={j_1,...,j_t} be a subset of [n]={1,...,n}, and let m_J denote the ideal (x_{j_1},...,x_{j_t}) of R. Given subsets J_1,...,J_s of [n] and positive integers a_1,...,a_s, we study ideals of the form I=m_{J_1}^{a_1} \cap ... \cap m_{J_s}^{a_s}. These ideals arise naturally, for example, in the study of fat points, tetrahedral curves, and Alexander duality of squarefree monomial ideals. Our main focus is determining when ideals of this form are componentwise linear. Using polymatroidality, we prove that I is always componentwise linear when s <= 3 or when J_i \cup J_j = [n] for all i \neq j. When s >= 4, we give examples to show that I may or may not be componentwise linear. We apply these results to ideals of small sets of general fat points in multiprojective space, and we extend work of Fatabbi, Lorenzini, Valla, and the first author by computing the graded Betti numbers in the s=2 case. Since componentwise linear ideals satisfy the Multiplicity Conjecture of Herzog, Huneke, and Srinivasan when char(k)=0, our work also yields new cases in which this conjecture holds.
Francisco Christopher A.
Tuyl Adam Van
No associations
LandOfFree
Some families of componentwise linear monomial ideals does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Some families of componentwise linear monomial ideals, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Some families of componentwise linear monomial ideals will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-21104