Displaying similar documents to “Projective embeddings of toric varieties”

Quotients of toric varieties by actions of subtori

Joanna Święcicka (1999)

Colloquium Mathematicae

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Let X be an algebraic toric variety with respect to an action of an algebraic torus S. Let Σ be the corresponding fan. The aim of this paper is to investigate open subsets of X with a good quotient by the (induced) action of a subtorus T ⊂ S. It turns out that it is enough to consider open S-invariant subsets of X with a good quotient by T. These subsets can be described by subfans of Σ. We give a description of such subfans and also a description of fans corresponding to quotient varieties....

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

Jan Ratajski (1993)

Colloquium Mathematicae

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Let X be the three-dimensional, complete, nonsingular, complex torus embedding corresponding to a fan S ⊆ ℝ 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.

A constructive proof that every 3-generated l-group is ultrasimplicial

Daniele Mundici, Giovanni Panti (1999)

Banach Center Publications

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We discuss the ultrasimplicial property of lattice-ordered abelian groups and their associated MV-algebras. We give a constructive proof of the fact that every lattice-ordered abelian group generated by three elements is ultrasimplicial.

Variational approach to some optimization control problems

R. Bianchini (1995)

Banach Center Publications

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This paper presents the variational approach to some optimization problems: Mayer's problem with or without constraints on the final point, local controllability of a trajectory, time-optimal problems.