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Related papers: On the polyhedrality of global Okounkov bodies

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Let $\mathscr{L} \rightarrow X$ be an ample line bundle over a complex normal projective variety $X$. We construct a flag $X_0 \subseteq X_1 \subseteq \cdots \subseteq X_n=X$ of subvarieties for which the associated Okounkov body for…

Algebraic Geometry · Mathematics 2014-09-09 Henrik Seppänen

We prove that the Okounkov body of a big divisor with respect to a general flag on a smooth projective surface whose pseudo-effective cone is rational polyhedral decomposes as the Minkowski sum of finitely many simplices and line segments…

Algebraic Geometry · Mathematics 2016-08-11 Patrycja Łuszcz-Świdecka , David Schmitz

We use the theory of Mori dream spaces to prove that the global Okounkov body of a Bott-Samelson variety with respect to a natural flag of subvarieties is rational polyhedral. In fact, we prove more generally that this holds for any Mori…

Algebraic Geometry · Mathematics 2015-03-31 David Schmitz , Henrik Seppänen

We show that the Okounkov body of a big divisor with finitely generated section ring is a rational simplex, for an appropriate choice of flag; furthermore, when the ambient variety is a surface, the same holds for every big divisor. Under…

Algebraic Geometry · Mathematics 2015-06-10 Dave Anderson , Alex Küronya , Victor Lozovanu

We compute Okounkov bodies of projective complexity-one T-varieties with respect to two types of invariant flags. In particular, we show that the latter are rational polytopes. Moreover, using results of Dave Anderson and Nathan Ilten, we…

Algebraic Geometry · Mathematics 2011-08-03 Lars Petersen

We define and study the global Okounkov moment cone of a projective spherical variety X, generalizing both the global Okounkov body and the moment body of X defined by Kaveh and Khovanskii. Under mild assumptions on X we show that the…

Algebraic Geometry · Mathematics 2017-10-02 Guido Pezzini , Henrik Seppänen

We first prove some basic properties of Okounkov bodies, and give a characterization of Nakayama and positive volume subvarieties of a pseudoeffective divisor in terms of Okounkov bodies. Next, we show that each valuative and limiting…

Algebraic Geometry · Mathematics 2017-04-25 Sung Rak Choi , Jinhyung Park , Joonyeong Won

Towards the boundary of the big cone, Newton-Okounkov bodies do not vary continuously and in fact the body of a boundary class is not well defined. Using the global Okounkov body one can nonetheless define a numerical invariant, the…

Algebraic Geometry · Mathematics 2016-07-14 William F. Sawin , David Schmitz

Let $\mathscr{L} \rightarrow X$ be an ample line bundle over a nonsingular complex projective variety $X$. We construct an admissable flag $X_0 \subseteq X_1 \subseteq...\subseteq X_n=X$ of subvarieties for which the associated Okounkov…

Complex Variables · Mathematics 2012-06-07 Henrik Seppänen

We prove that for smooth projective toric varieties, the Okounkov body of a $T$-invariant pseudo-effective divisor with respect to a $T$-invariant flag decomposes as a finite Minkowski sum of indecomposable polytopes. We prove that these…

Algebraic Geometry · Mathematics 2016-01-20 Piotr Pokora , David Schmitz , Stefano Urbinati

Based on the work of Okounkov (\cite{Ok96}, \cite{Ok03}), Lazarsfeld and Musta\c t\u a (\cite{LM08}) and Kaveh and Khovanskii (\cite{KK08}) have independently associated a convex body, called the Okounkov body, to a big divisor on a smooth…

Algebraic Geometry · Mathematics 2010-08-27 Alex Kuronya , Victor Lozovanu , Catriona Maclean

The global Okounkov body of a projective variety is a closed convex cone that encodes asymptotic information about every big line bundle on the variety. In the case of a rank two toric vector bundle E on a smooth projective toric variety,…

Algebraic Geometry · Mathematics 2011-01-04 José Luis González

The purpose of this note is to study the number of elements in Minkowski bases on algebraic surfaces with rational polyhedral pseudo-effective cone.

Algebraic Geometry · Mathematics 2016-01-20 Piotr Pokora , Tomasz Szemberg

Assume that the valuation semigroup $\Gamma(\lambda)$ of an arbitrary partial flag variety corresponding to the line bundle $\mathcal L_\lambda$ constructed via a full-rank valuation is finitely generated and saturated. We use Ehrhart…

Algebraic Geometry · Mathematics 2020-11-24 Christian Steinert

Given a smooth Mori dream space $X$ we construct a model dominating all the small $\mathbb{Q}$-factorial modifications via tropicalization. This construction allows us to recover a Minkowski basis for the Newton-Okounkov bodies of divisors…

Algebraic Geometry · Mathematics 2018-01-26 Elisa Postinghel , Stefano Urbinati

The aim of the present paper is to prove the rationality of the universal family of polarized $ K3 $ surfaces of degree 14. This is achieved by identifying it with the moduli space of cubic fourfolds plus the data of a quartic scroll. The…

Algebraic Geometry · Mathematics 2020-05-26 Daniele Di Tullio

Let $G'$ be a complex semisimple group, and let $G \subseteq G'$ be a semisimple subgroup. We show that the branching cone of the pair $(G, G')$, which (asymptotically) parametrizes all pairs $(W, V)$ of irreducible finite-dimensional…

Representation Theory · Mathematics 2014-09-09 Henrik Seppänen

We prove that on a Bott-Samelson variety $X$ every movable divisor is nef. This enables us to consider Zariski decompositions of effective divisors, which in turn yields a description of the Mori chamber decomposition of the effective cone.…

Algebraic Geometry · Mathematics 2017-11-27 Georg Merz , David Schmitz , Henrik Seppänen

In this note, we work out a simple inductive proof showing that every polyhedral cone K is the conic hull of a finite set X of vectors. The base cases of the induction are linear subspaces and linear halfspaces of linear subspaces. The…

Combinatorics · Mathematics 2009-12-16 Volker Kaibel

The Okounkov body is a construction which, to an effective divisor D on an n-dimensional algebraic variety X, associates a convex body in the n-dimensional Euclidean space R^n. It may be seen as a generalization of the moment polytope of an…

Algebraic Geometry · Mathematics 2016-03-04 Shin-Yao Jow
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