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manuscripta mathematica

, Volume 120, Issue 1, pp 27–38 | Cite as

The Rees algebra of a positive normal affine semigroup ring

  • Attila WiebeEmail author
Article

Abstract

Let R be a positive normal affine semigroup ring of dimension d and let Open image in new window be the maximal homogeneous ideal of R. We show that the integral closure Open image in new window of Open image in new window is equal to Open image in new window for all n ∈ℕ with nd − 2. From this we derive that the Rees algebra R[ Open image in new window t] is normal in case that d ≤ 3. If emb dim(R) = d + 1, we can give a necessary and sufficient condition for R[ Open image in new window t] to be normal.

Keywords

Number Theory Algebraic Geometry Topological Group Integral Closure Homogeneous Ideal 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  1. 1.FB MathematikUniversität Duisburg-EssenEssenGermany

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