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Related papers: Okounkov bodies for ample line bundles

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Let $X$ be a smooth complex projective variety and let $H \in \pic(X)$ be an ample line bundle. Assume that $X$ is covered by rational curves with degree one with respect to $H$ and with anticanonical degree greater than or equal to $(\dim…

Algebraic Geometry · Mathematics 2019-08-15 Carla Novelli , Gianluca Occhetta

Let $X$ be a projective manifold of dimension $n$. Suppose that $T_X$ contains an ample subsheaf. We show that $X$ is isomorphic to $\mathbb{P}^n$. As an application, we derive the classification of projective manifolds containing a…

Algebraic Geometry · Mathematics 2017-10-12 Jie Liu

Let X be a smooth projective variety and let K be the canonical divisor of X. In this paper, we study embeddings of X given by adjoint line bundles of the form K+L, where L is an ample line bundle. When X is a regular surface (i.e. H^1(X,…

Algebraic Geometry · Mathematics 2007-09-13 Huy Tai Ha

We construct a continuous 3-parameter family of non-shrinking Ricci solitons complex line bundles $O(k)$ over $\mathbb{CP}^{2m+1}$, where the base space is not necessarily K\"ahler--Einstein. Each $O(k)$ with $k\in [3,2m+1]$ admits at least…

Differential Geometry · Mathematics 2026-03-17 Hanci Chi

Let $X$ be a projective toric variety of dimension $n$ and let $L$ be a ample line bundle on $X$. For $k \geq 0$, it is in general difficult to determine whether $L^{\otimes k}$ is very ample and whether it additionally gives a projectively…

Algebraic Geometry · Mathematics 2026-02-25 Praise Adeyemo , Dominic Bunnett , Fabián Levicán-Santibáñez

Let $X$ be the special fiber of a unitary Shimura variety of hyperspecial level at a prime $p$ inert in the totally real field $F$. Let $Y\to X$ be the associated flag space. For every $L$-dominant weight $\lambda$, let…

Number Theory · Mathematics 2026-05-05 Deding Yang

Let $X \rightarrow S$ be a smooth projective surjective morphism, where $X$ and $S$ are integral schemes over complex numbers. Let L_0, L_1, .... L_{n-1}, L_{n} be line bundles over $X$. There is a natural isomorphism of the Deligne pairing…

Algebraic Geometry · Mathematics 2011-06-07 Indranil Biswas , Georg Schumacher , Lin Weng

We generalize the theory of Newton-Okounkov bodies of big divisors to the case of graded linear series. One of the results is the generalization of slice formulas and the existence of generic Newton-Okounkov bodies for birational graded…

Algebraic Geometry · Mathematics 2018-01-16 Georg Merz

A Newton-Okounkov convex body is a convex body constructed from a projective variety with a valuation on its homogeneous coordinate ring; this generalizes a Newton polytope for a toric variety. This convex body has various kinds of…

Representation Theory · Mathematics 2016-02-24 Naoki Fujita

We classify smooth complex projective varieties $X \subset \proj^N$ of dimension $2s+1$ containing a linear subspace $\Lambda$ of dimension $s$ whose normal bundle $N_{\Lambda/X}$ is numerically effective.

Algebraic Geometry · Mathematics 2015-11-04 Carla Novelli , Gianluca Occhetta

We study sections of line bundles on the nested Hilbert scheme of points on the affine plane. We describe the spaces of sections in terms of certain ideals introduced by Haiman, and find explicit bases for them by analyzing the trailing…

Algebraic Geometry · Mathematics 2025-10-10 Ian Cavey , Eugene Gorsky , Alexei Oblomkov , Joshua P. Turner

We describe, under certain conditions, the Newton-Okounkov body of a Bott-Samelson variety as a lattice polytope defined by an explicit list of inequalities. The valuation that we use to define the Newton-Okounkov body is different from…

Algebraic Geometry · Mathematics 2018-06-20 Megumi Harada , Jihyeon Jessie Yang

The aim of this paper is to study the Okounkov bodies associated to abundant divisors. As a main result, we prove that the valuative Okounkov bodies of an abundant divisor encode all the numerical properties. We apply this result to recover…

Algebraic Geometry · Mathematics 2021-11-02 Sung Rak Choi , Jinhyung Park , Joonyeong Won

Let $X$ be a projective nonsingular toric 3-fold with a surjective torus equivariant morphism onto the projective line. Then we prove that an ample line bundle on $X$ is always normally generated.

Algebraic Geometry · Mathematics 2023-09-21 Shoetsu Ogata

Let $K$ be the function field of a smooth curve over an algebraically closed field $k$. Let $X$ be a scheme, which is smooth and projective over $K$. Suppose that the cotangent bundle $\Omega_{X/K}$ is ample. Let $R:={\rm Zar}(X)(K)\cap X)$…

Algebraic Geometry · Mathematics 2017-06-27 Henri Gillet , Damian Rössler

In this paper we characterize smooth complex projective varieties that admit a quadric bundle structure on some dense open subset in terms of the geometry of certain families of rational curves.

Algebraic Geometry · Mathematics 2008-11-07 Carolina Araujo

Let $X$ be a projective variety and let $C$ be a rational normal curve on $X$. We compute the normal bundle of $C$ in a general complete intersection of hypersurfaces of sufficiently large degree in $X$. As a result, we establish the…

Algebraic Geometry · Mathematics 2021-06-04 Izzet Coskun , Geoffrey Smith

A flag variety is a smooth projective homogeneous variety. In this paper, we study Newton-Okounkov polytopes of the flag variety $Fl(\mathbb{C}^4)$ arising from its cluster structure. More precisely, we present defining inequalities of such…

Algebraic Geometry · Mathematics 2023-10-11 Yunhyung Cho , Naoki Fujita , Akihiro Higashitani , Eunjeong Lee

Let $C \subset \mathbb{P}^2$ be an irreducible and reduced curve of degree $e > 0$. Let $X$ be the blow up of $\mathbb{P}^2$ at $r$ distinct smooth points $p_1,\ldots,p_r \in C$. We study line bundles on $X$ and establish conditions for…

Algebraic Geometry · Mathematics 2017-01-09 Krishna Hanumanthu

In dimension two, we reduce the classification problem for asymptotically log Fano pairs to the problem of determining generality conditions on certain blow-ups. In any dimension, we prove the rationality of the body of ample angles of an…

Algebraic Geometry · Mathematics 2024-11-20 Paolo Cascini , Jesus Martinez-Garcia , Yanir A. Rubinstein