Abstract
In this paper, we prove that the arithmetical rank of a squarefree monomial ideal I is equal to the projective dimension of R/I in the following cases: (a) I is an almost complete intersection; (b) arithdeg∈I=reg∈I; (c) arithdeg∈I=indeg∈I+1. We also classify all almost complete intersection squarefree monomial ideals in terms of hypergraphs, and use this classification in the proof in case (c).
Original language | English |
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Pages (from-to) | 389-404 |
Number of pages | 16 |
Journal | Journal of Algebraic Combinatorics |
Volume | 29 |
Issue number | 3 |
DOIs | |
Publication status | Published - May 2009 |
Externally published | Yes |
Keywords
- Alexander duality
- Almost complete intersection
- Arithmetic degree
- Arithmetical rank
- Initial degree
- Regularity
ASJC Scopus subject areas
- Algebra and Number Theory
- Discrete Mathematics and Combinatorics