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Related papers: Tropical Fano Schemes

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The main result of this paper is a structural theorem for projective Q-factorial toric varieties X in P^N, covered by lines. We prove that there exists a toric fibration f: X -> Z, locally trivial in the Zariski topology, with fiber a…

Algebraic Geometry · Mathematics 2007-05-23 C. Casagrande , S. Di Rocco

Let $X$ be a smooth projective variety defined over an algebraically closed field of positive characteristic $p$ whose tangent bundle is nef. We prove that $X$ admits a smooth morphism $X \to M$ such that the fibers are Fano varieties with…

Algebraic Geometry · Mathematics 2020-12-18 Akihiro Kanemitsu , Kiwamu Watanabe

This paper is about the combinatorics of finite point configurations in the tropical projective space or, dually, of arrangements of finitely many tropical hyperplanes. Moreover, arrangements of finitely many tropical halfspaces can be…

Combinatorics · Mathematics 2019-06-21 Michael Joswig , Georg Loho

Smooth tropical cubic surfaces are parametrized by maximal cones in the unimodular secondary fan of the triple tetrahedron. There are $344\, 843 \,867$ such cones, organized into a database of $14\,373\,645$ symmetry classes. The Schl\"afli…

Combinatorics · Mathematics 2021-08-03 Michael Joswig , Marta Panizzut , Bernd Sturmfels

We prove that every balanced 1-dimensional polyhedral complex arises as the tropicalization of a smooth curve over a non-Archimedean field mapping to a toric Artin fan, namely the quotient of a toric variety by its dense torus.

Algebraic Geometry · Mathematics 2017-06-20 Dhruv Ranganathan

In this paper we illustrate an algorithmic procedure which allows to build projective wonderful models for the complement of a toric arrangement in a n-dimensional algebraic torus T. The main step of the construction is a combinatorial…

Algebraic Geometry · Mathematics 2016-09-01 Corrado De Concini , Giovanni Gaiffi

Every tropical ideal in the sense of Maclagan-Rinc\'on has an associated tropical variety, a finite polyhedral complex equipped with positive integral weights on its maximal cells. This leads to the realisability question, ubiquitous in…

Combinatorics · Mathematics 2021-06-29 Jan Draisma , Felipe Rincón

The hypertoric variety $\mathfrak{M}_{\mathcal{A}}$ defined by an affine arrangement $\mathcal{A}$ admits a natural tropicalization, induced by its embedding in a Lawrence toric variety. We explicitly describe the polyhedral structure of…

Algebraic Geometry · Mathematics 2016-04-29 Max B. Kutler

Following DeMeyer, Ford & Miranda [DFM93], we define a topology on a fan by declaring open sets to be its subfans. Then, like Kato [Kat94], we make our fans into monoided spaces by associating a sheaf of monoids to each fan. (Our sheaf of…

Algebraic Geometry · Mathematics 2007-05-23 Howard M Thompson

A root system $R$ of rank $n$ defines an $n$-dimensional smooth projective toric variety $X(R)$ associated with its fan of Weyl chambers. We give a simple description of the functor of $X(R)$ in terms of the root system $R$ and apply this…

Algebraic Geometry · Mathematics 2012-01-17 Victor Batyrev , Mark Blume

We prove that the Fano variety of lines of a generic cubic fourfold containing a plane is isomorphic to a moduli space of twisted stable complexes on a K3 surface. On the other hand, we show that the Fano varieties are always birational to…

Algebraic Geometry · Mathematics 2011-12-26 Emanuele Macri , Paolo Stellari

This article discusses the concept of rational equivalence in tropical geometry (and replaces the older and imperfect version arXiv:0811.2860). We give the basic definitions in the context of tropical varieties without boundary points and…

Algebraic Geometry · Mathematics 2019-10-14 Lars Allermann , Simon Hampe , Johannes Rau

The map which takes a square matrix $A$ to its polytrope is piecewise linear. We show that cones of linearity of this map form a polytopal fan partition of $\{R}^{n \times n}$, whose face lattice is anti-isomorphic to the lattice of…

Combinatorics · Mathematics 2013-02-22 Ngoc M. Tran

We show that the weights on a tropical variety can be recovered from the tropical scheme structure proposed by the Giansiracusas in arXiv:1308.0042, so there is a well-defined Hilbert-Chow morphism from a tropical scheme to the underlying…

Algebraic Geometry · Mathematics 2017-12-12 Diane Maclagan , Felipe Rincón

To any graph $G$ one can associate a toric variety $X(\mathcal{P}G)$, obtained as a blowup of projective space along coordinate subspaces corresponding to connected subgraphs of $G$. The polytope of this toric variety is the graph…

Algebraic Geometry · Mathematics 2017-06-06 Rodrigo Ferreira da Rosa , David Jensen , Dhruv Ranganathan

Tropicalization is a procedure for associating a polyhedral complex in Euclidean space to a subvariety of an algebraic torus. We study the question of which graphs arise from tropicalizing algebraic curves. By using Baker's specialization…

Algebraic Geometry · Mathematics 2011-08-23 Eric Katz

In this paper, we obtain a complete classification of smooth toric Fano varieties equipped with extremal contractions which contract divisors to curves for any dimension. As an application, we obtain a complete classification of smooth…

Algebraic Geometry · Mathematics 2007-05-23 Hiroshi Sato

We define Stasheff polytopes in the space of tropical points of cluster A-varieties. We study the supports of products of elements of canonical bases for cluster X-varieties. We prove that, for the cluster X-variety of type A_n, such…

Algebraic Geometry · Mathematics 2015-11-05 Linhui Shen

This paper obtains criteria for a Fano variety X with normal crossing singularities defined over an algebraically closed field of characteristic zero, to be smoothable. The difference with the original version is that the theory of…

Algebraic Geometry · Mathematics 2013-07-09 Nikolaos Tziolas

The purpose of this paper is to give basic tools for the classification of nonsingular toric Fano varieties by means of the notions of primitive collections and primitive relations due to Batyrev. By using them we can easily deal with…

Algebraic Geometry · Mathematics 2007-05-23 Hiroshi Sato
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