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Related papers: On non-projective complete toric varieties

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We show that every morphism from a degree 5 hypersurface in 4-dimensional projective space to a nonsingular degree 3 hypersurface in 4-dimensional projective space is necessarily constant. In the process, we also classify morphisms from the…

Algebraic Geometry · Mathematics 2007-05-23 David Sheppard

In this note we gather and review some facts about existence of toric spaces over 3-dimensional simple polytopes. First, over every combinatorial 3-polytope there exists a quasitoric manifold. Second, there exist combinatorial 3-polytopes,…

Algebraic Topology · Mathematics 2026-02-10 Anton Ayzenberg

To each complex composition algebra $\mathbb{A}$, there associates a projective symmetric manifold $X(\mathbb{A})$ of Picard number one, which is just a smooth hyperplane section of the following varieties ${\rm Lag}(3,6), {\rm Gr}(3,6),…

Algebraic Geometry · Mathematics 2026-05-27 Yifei Chen , Baohua Fu , Qifeng Li

We describe all of the smooth complete toric threefolds of Picard number 5 with no nontrivial nef line bundles, and show that no such examples exist with Picard number less than 5.

Algebraic Geometry · Mathematics 2007-06-23 Osamu Fujino , Sam Payne

We give various examples of Q-factorial projective toric varieties such that the sum of the squared torus invariant prime divisors is positive. We also determine the generators for the cone of effective $2$-cycles on a toric variety of…

Algebraic Geometry · Mathematics 2019-12-18 Hiroshi Sato , Yusuke Suyama

In this paper, we investigate when there exists a wild hypersurface bundle over a smooth proper toric variety in positive characteristic. In particular, we determine the possibilities for toric varieties with Picard number at most three or…

Algebraic Geometry · Mathematics 2007-05-23 Hiroshi Sato

Let $X$ be a normal projective variety and $f:X\to X$ a non-isomorphic polarized endomorphism. We give two characterizations for $X$ to be a toric variety. First we show that if $X$ is $\mathbb{Q}$-factorial and $G$-almost homogeneous for…

Algebraic Geometry · Mathematics 2019-08-05 Sheng Meng , De-Qi Zhang

This paper proves that every projective toric variety is the fine moduli space for stable representations of an appropriate bound quiver. To accomplish this, we study the quiver $Q$ with relations $R$ corresponding to the finite-dimensional…

Algebraic Geometry · Mathematics 2010-03-15 Alastair Craw , Gregory G. Smith

We show that if X is a smooth rationally connected threefold and C is a smooth projective curve then C can be embedded in X. Furthermore, a version of this property characterises rationally connected varieties of dimension at least 3. We…

Algebraic Geometry · Mathematics 2010-02-05 G. K. Sankaran

We give a characterization of all complete smooth toric varieties whose rational homotopy is of elliptic type. All such toric varieties of complex dimension not more than three are explicitly described.

Algebraic Geometry · Mathematics 2020-02-04 Indranil Biswas , Vicente Munoz , Aniceto Murillo

In this paper, we give a method to describe the numerical class of a torus invariant surface on a projective toric manifold. As applications, we can classify toric 2-Fano manifolds of Picard number 2 or of dimension at most 4.

Algebraic Geometry · Mathematics 2011-06-30 Hiroshi Sato

Let $X$ be a rationally connected smooth projective variety of dimension $n$. We show that $X$ is a toric variety if and only if $X$ admits an int-amplified endomorphism with totally invariant ramification divisor. We also show that $X\cong…

Algebraic Geometry · Mathematics 2023-09-19 Sheng Meng , Guolei Zhong

It is proved that the degree of a morphism from a smooth projective n-fold with Picard number one to a smooth n-quadric is bounded (provided, of course, that n is at least three). Actually it has been proved some years ago, but I have never…

Algebraic Geometry · Mathematics 2007-05-23 Ekaterina Amerik

Let $X$ be a complete $\mathbb{Q}$-factorial toric variety. We explicitly describe the space $H^2(X,T_X)$ and the cup product map $H^1(X,T_X)\times H^1(X,T_X)\to H^2(X,T_X)$ in combinatorial terms. Using this, we give an example of a smooth…

Algebraic Geometry · Mathematics 2020-06-24 Nathan Ilten , Charles Turo

We show that the usual sufficient criterion for a generic hypersurface in a smooth projective manifold to have the same Picard number as the ambient variety can be generalized to hypersurfaces in complete simplicial toric varieties. This…

Algebraic Geometry · Mathematics 2013-05-29 Ugo Bruzzo , Antonella Grassi

A fake weighted projective space X is a Q-factorial toric variety with Picard number one. As with weighted projective space, X comes equipped with a set of weights (\lambda_0,...,\lambda_n). We see how the singularities of…

Algebraic Geometry · Mathematics 2022-10-28 Alexander Kasprzyk

We construct a projective variety with discrete, non-finitely generated automorphism group. As an application, we show that there exists a complex projective variety with infinitely many non-isomorphic real forms.

Algebraic Geometry · Mathematics 2017-02-08 John Lesieutre

Algebraic hyperbolicity serves as a bridge between differential geometry and algebraic geometry. Generally, it is difficult to show that a given projective variety is algebraically hyperbolic. However, it was established recently that a…

Algebraic Geometry · Mathematics 2024-10-01 Sharon Robins

We show, among other things, that for each integer $n \ge 3$, there is a smooth complex projective rational variety of dimension $n$, with discrete non-finitely generated automorphism group and with infinitely many mutually non-isomorphic…

Algebraic Geometry · Mathematics 2021-05-11 Tien-Cuong Dinh , Keiji Oguiso , Xun Yu

We prove that every Q-factorial complete toric variety is a finite quotient of a poly weighted space (PWS), as defined in our previous work arXiv:1501.05244. This generalizes the Batyrev-Cox and Conrads description of a Q-factorial complete…

Algebraic Geometry · Mathematics 2018-05-21 Michele Rossi , Lea Terracini