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We show that the equivariant Chow cohomology ring of a toric variety is naturally isomorphic to the ring of integral piecewise polynomial functions on the associated fan. This gives a large class of singular spaces for which localization…

Algebraic Geometry · Mathematics 2007-06-23 Sam Payne

We classify all smooth projective toric surfaces $S$ containing exactly one exceptional curve. We show that every such surface $S$ is isomorphic to either $\mathbb{F}_1$ or a surface $S_r$ defined by a rational number $r \in \mathbb{Q}…

Algebraic Geometry · Mathematics 2024-12-17 Victor Batyrev

Let $X$ be a smooth $n$-dimensional Fano hypersurface in $\mathbb P^{n+1}$ where $n \geq 3$. Let $\Gamma$ be a smooth positive-dimensional complete intersection of $X$, a hypersurface and one of more hyperplanes in $\mathbb P^{n+1}$. Let $Y…

Algebraic Geometry · Mathematics 2026-05-06 Livia Campo , Tiago Duarte Guerreiro , Erik Paemurru

We investigate Gorenstein toric Fano varieties by combinatorial methods using the notion of a reflexive polytope which appeared in connection to mirror symmetry. The paper contains generalisations of tools and previously known results for…

Algebraic Geometry · Mathematics 2007-05-23 Benjamin Nill

Firstly, we see that the bases of the miniversal deformations of isolated $\mathbb{Q}$-Gorenstein toric singularities are quite restricted. In particular, we classify the analytic germs of embedding dimension $\leq 2$ which are the bases of…

Algebraic Geometry · Mathematics 2022-09-13 Andrea Petracci

Given any field $k$ (not necessarily perfect), we study the smoothing of a semistable Fano variety over $k$. In characteristic 0, the reduced semistable Fano degenerate fibers of Mori fibrations are classified. In positive characteristic,…

Algebraic Geometry · Mathematics 2016-06-03 Junchao Shentu

Let $X^{1,n}_r$ be the blow-up of $\mathbb{P}^1\times\mathbb{P}^n$ in $r$ general points. We describe the Mori cone of $X^{1,n}_r$ for $r\leq n+2$ and for $r = n+3$ when $n\leq 4$. Furthermore, we prove that $X^{1,n}_{n+1}$ is log Fano and…

Algebraic Geometry · Mathematics 2023-08-23 Michele Bolognesi , Alex Massarenti , Elena Poma

Toric varieties are a special class of rational varieties defined by equations of the form {\it monomial = monomial}. For a good brief survey of the history and role of toric varieties see [10]. Any toric variety $X$ contains a cover by…

alg-geom · Mathematics 2008-02-03 Frank DeMeyer , Tim Ford , Rick Miranda

We present a complete classification of normal toric surfaces that are resolved by a single normalized Nash blowup. Likewise, we obtain a complete classification of those resolved by a single Nash blowup. In both cases, the classification…

Algebraic Geometry · Mathematics 2025-12-01 Amador Cruz-Fuentes

In this paper, we prove that a Gorenstein toric Fano variety $(X, -K_{X})$ is asymptotically Chow semistable then it is Ding polystable with respect to toric test configurations (Theorem 1.3). This extends the known result obtained by…

Differential Geometry · Mathematics 2023-10-23 Naoto Yotsutani

Given $X$ a smooth projective toric variety, we construct a morphism from a closed substack of the moduli space of stable maps to $X$ to the moduli space of quasimaps to $X$. If $X$ is Fano, we show that this morphism is surjective. The…

Algebraic Geometry · Mathematics 2024-12-24 Alberto Cobos Rabano

We introduce admissible Minkowski decomposition data (amd) for a 3-dimensional reflexive polytope P. This notion is defined purely in terms of the combinatorics of P. Denoting by X the Gorenstein toric Fano 3-fold whose fan is the spanning…

Algebraic Geometry · Mathematics 2024-12-10 Alessio Corti , Paul Hacking , Andrea Petracci

We classify Fano fivefolds of index two which are blow-ups of smooth manifolds along a smooth center.

Algebraic Geometry · Mathematics 2017-09-29 Elena Chierici , Gianluca Occhetta

Normal toric varieties over a field or a discrete valuation ring are classified by rational polyhedral fans. We generalize this classification to normal toric varieties over an arbitrary valuation ring of rank one. The proof is based on a…

Algebraic Geometry · Mathematics 2015-01-30 Walter Gubler , Alejandro Soto

We prove categorical Torelli theorems for four families of Fano double covers with Picard rank greater than 1. Among these is the family of Verra fourfolds. The other three families manifest as double covers of Fano threefolds, branched in…

Algebraic Geometry · Mathematics 2026-05-18 Augustinas Jacovskis , Reinder Meinsma

Let X be a smooth, complex Fano variety, and delta(X) its Lefschetz defect. It is known that if delta(X) is at least 4, then X is isomorphic to a product SxT, where dim T=dim X-2. In this paper we prove a structure theorem for the case…

Algebraic Geometry · Mathematics 2022-12-14 C. Casagrande , E. A. Romano , S. A. Secci

We construct a full, strongly exceptional collection of line bundles on the variety X that is the blow up of the projectivization of the vector bundle O_{P^{n-1}}\oplus O_{P^{n-1}}(b) along a linear space of dimension n-2, where b is a…

Algebraic Geometry · Mathematics 2010-02-19 Arijit Dey , Michal Lason , Mateusz Michalek

We prove the Mukai conjecture on the characterisation of products of projective spaces among Fano varieties for a class of locally factorial Fano varieties defined in terms of their Cox rings. The Fano varieties of this class are…

Algebraic Geometry · Mathematics 2026-04-29 Heath Pearson

We generalized the construction of deformations of affine toric varieties of K. Altmann and our previous construction of deformations of weak Fano toric varieties to the case of arbitrary toric varieties by introducing the notion of…

Algebraic Geometry · Mathematics 2011-02-25 Anvar Mavlyutov

The cohomological rigidity problem for toric manifolds asks whether toric manifolds are diffeomorphic (or homeomorphic) if their integral cohomology rings are isomorphic. Many affirmative partial solutions to the problem have been obtained…

Algebraic Topology · Mathematics 2020-05-29 Akihiro Higashitani , Kazuki Kurimoto , Mikiya Masuda