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Proceedings of the American Mathematical Society

Published by the American Mathematical Society since 1950, Proceedings of the American Mathematical Society is devoted to shorter research articles in all areas of pure and applied mathematics.

ISSN 1088-6826 (online) ISSN 0002-9939 (print)

The 2020 MCQ for Proceedings of the American Mathematical Society is 0.85.

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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