Displaying similar documents to “Computing the integral closure of an affine semigroup.”

On the Betti numbers of the real part of a three-dimensional torus embedding

Jan Ratajski (1993)

Colloquium Mathematicae

Similarity:

Let X be the three-dimensional, complete, nonsingular, complex torus embedding corresponding to a fan S 3 and let V be the real part of X (for definitions see [1] or [3]). The aim of this note is to give a simple combinatorial formula for calculating the Betti numbers of V.

Centers in domains with quadratic growth

Agata Smoktunowicz (2005)

Open Mathematics

Similarity:

Let F be a field, and let R be a finitely-generated F-algebra, which is a domain with quadratic growth. It is shown that either the center of R is a finitely-generated F-algebra or R satisfies a polynomial identity (is PI) or else R is algebraic over F. Let r ∈ R be not algebraic over F and let C be the centralizer of r. It is shown that either the quotient ring of C is a finitely-generated division algebra of Gelfand-Kirillov dimension 1 or R is PI.