In this paper we prove parts of a conjecture of Herzog giving lower bounds on the rank of the free modules appearing in the linear strand of a graded kth syzygy module over the polynomial ring. If in addition the module is β«ήβ¬ n -graded we show that the conjecture holds in full generality. Furthermo
Smallest Graded Betti Numbers
β Scribed by Benjamin P Richert
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 153 KB
- Volume
- 244
- Category
- Article
- ISSN
- 0021-8693
No coin nor oath required. For personal study only.
β¦ Synopsis
It is known that given a Hilbert function H H, there need not exist a module which has uniquely the smallest graded Betti numbers among all modules attaining H H. In this paper we extend the previous example of this behavior to an infinite family and demonstrate with a second infinite family that even when the given Hilbert function is that of a complete intersection, a module with uniquely smallest graded Betti numbers need not exist. Finally we prove a conjecture of Geramita, Harima, and Shin concerning the non-existence of uniquely smallest graded Betti numbers among all Gorenstein rings attaining a given Hilbert function.
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