On openness of $H_{n}$-locus and semicontinuity of $n$th deviation
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- by Alfio Ragusa PDF
- Proc. Amer. Math. Soc. 80 (1980), 201-209 Request permission
Abstract:
M. André has used the property ${H_n}$, namely the vanishing of certain homology groups, and the deviation ${\delta _n}$ to characterize some classes of rings. In the present paper the author establishes an inequality on the deviations and obtains a Nagata criterion for ${H_n}$-locus and its openness for quotients of complete intersection rings and excellent rings. The upper-semicontinuity for ${\delta _n}$ is also proved for the same classes of rings.References
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Additional Information
- © Copyright 1980 American Mathematical Society
- Journal: Proc. Amer. Math. Soc. 80 (1980), 201-209
- MSC: Primary 13D03; Secondary 13H10
- DOI: https://doi.org/10.1090/S0002-9939-1980-0577744-1
- MathSciNet review: 577744