Abstract
Let R be a Cohen-Macaulay local ring of dimension one with a canonical module KR. Let I be a faithful ideal of R. We explore the problem of when I⊗RI∨ is torsionfree, where I∨=HomR(I, KR). We prove that if R has multiplicity at most 6, then I is isomorphic to R or KR as an R-module, once I⊗RI∨ is torsionfree. This result is applied to monomial ideals of numerical semigroup rings. A higher dimensional assertion is also discussed.
Original language | English |
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Pages (from-to) | 33-52 |
Number of pages | 20 |
Journal | Journal of Algebra |
Volume | 422 |
DOIs | |
Publication status | Published - 2015 Jan 5 |
Externally published | Yes |
Keywords
- Canonical module
- Cohen-Macaulay ring
- Gorenstein ring
- Multiplicity
- Numerical semigroup ring
- Torsionfree
ASJC Scopus subject areas
- Algebra and Number Theory