中文
相关论文

相关论文: On the birational geometry of toric Fano 4-folds

200 篇论文

We classify three-dimensional nodal Fano varieties that are double covers of smooth quadrics branched over intersections with quartics acted on by finite simple non-abelian groups, and study their rationality.

代数几何 · 数学 2018-08-07 Victor Przyjalkowski , Constantin Shramov

We complete the analysis on the birational rigidity of quasismooth Fano 3-fold deformation families appearing in the Graded Ring Database as a complete intersection. When such a deformation family $X$ has Fano index at least 2 and is…

代数几何 · 数学 2023-01-18 Tiago Duarte Guerreiro

We show that any quasismooth Fano threefold weighted complete intersections of type $(12, 14)$ in $\mathbb{P} (1, 2, 3, 4, 7, 11)$ is birationally solid.

代数几何 · 数学 2025-11-10 Takuzo Okada

Suppose that X to Y is a generically finite map of nonsingular varieties over a field of characteristic zero, and v is a valuation of the function field of X. We prove that it is possible to perform a sequence of monoidal transforms X' to X…

代数几何 · 数学 2007-05-23 Steven Dale Cutkosky

We obtain 866 isomorphism classes of five-dimensional nonsingular toric Fano varieties using a computer program and the database of four-dimensional reflexive polytopes. The algorithm is based on the existence of facets of Fano polytopes…

代数几何 · 数学 2010-02-14 Maximilian Kreuzer , Benjamin Nill

We classify projective terminalizations of quotients of Fano varieties of lines on smooth cubic fourfolds by finite groups of symplectic automorphisms of the underlying cubic. We compute the second Betti number and the fundamental group of…

代数几何 · 数学 2026-02-19 Enrica Mazzon

We develop an equivariant version of the Pfaffian-Grassmannian correspondence and apply it to produce examples of nontrivial twisted equivariant stable birationalities between cubic threefolds and degree 14 Fano threefolds.

代数几何 · 数学 2024-09-16 Yuri Tschinkel , Zhijia Zhang

We classify the terminal Fano threefolds of Picard number one that come with an effective action of a two-torus. Our approach applies also to higher dimensions and generalizes the correspondence between toric Fano varieties and lattice…

代数几何 · 数学 2025-07-08 Benjamin Bechtold , Elaine Huggenberger , Juergen Hausen , Michele Nicolussi

We show boundedness of $3$-folds of $\epsilon$-Fano type with Mori fibration structures. The proof is based on the birational boundedness result in our previous work arXiv:1509.08722 combining with arguments in Kawamata \cite{K} and…

代数几何 · 数学 2020-09-01 Chen Jiang

In this paper, we give some results on the birational geometry of varieties of Fano type and boundedness problems in positive characteristic, including a result ensuring that boundedness is invariant under normalizations, a canonical bundle…

代数几何 · 数学 2025-03-10 Xintong Jiang

We find a characterization for Fano 4-folds $X$ with Lefschetz defect $\delta_{X}=3$: besides the product of two del Pezzo surfaces, they correspond to varieties admitting a conic bundle structure $f\colon X\to Y$ with…

代数几何 · 数学 2019-06-26 Pedro Montero , Eleonora Anna Romano

We classify Fano 3-folds with canonical Gorenstein singularities whose anticanonical linear system has no base points but does not give an embedding, and we classify anticanonically embedded Fano 3-folds with canonical Gorenstein…

代数几何 · 数学 2007-05-23 Ivan Cheltsov , Constantin Shramov , Victor Przyjalkowski

We classify complex projective manifolds $X$ for which there exists a point $a$ such that the blow-up of $X$ at $a$ is Fano.

代数几何 · 数学 2007-05-23 L. Bonavero , F. Campana , J. A. Wiśniewski

Suppose that $f:X\to Y$ is a dominant morphism of 3-folds over an algebraically closed field of characteristic zero. We prove that there exist sequences of blow ups of points and nonsingular curves $\Phi:X_1\to X$ and $\Psi:Y_1\to Y$ such…

代数几何 · 数学 2007-05-23 Steven Dale Cutkosky

For an arbitrary smooth n-dimensional Fano variety $X$ we introduce the notion of a small toric degeneration. Using small toric degenerations of Fano n-folds $X$, we propose a general method for constructing mirrors of Calabi-Yau complete…

alg-geom · 数学 2007-05-23 Victor V. Batyrev

We study the symplectic resolution of the Fano variety of lines on some singular cyclic cubic fourfolds, i.e. cubic fourfolds arising as cyclic 3:1 cover of $\mathbb{P}^4$ branched along a cubic threefold. In particular we are interested in…

代数几何 · 数学 2023-12-27 Samuel Boissière , Paola Comparin , Lucas Li Bassi

We prove that any affine, resp. polarized projective, spherical variety admits a flat degeneration to an affine, resp. polarized projective, toric variety. Motivated by Mirror Symmetry, we give conditions for the limit toric variety to be a…

代数几何 · 数学 2007-05-23 Valery Alexeev , Michel Brion

In this paper, we introduce the notion of toric special weak Fano manifolds, which have only special primitive crepant contractions. We study the structure of them, and in particular completely classify smooth toric special weak Fano…

代数几何 · 数学 2021-05-26 Hiroshi Sato

We construct families of non-toric $\mathbb{Q}$-factorial terminal Fano ($\mathbb{Q}$-Fano) threefolds of codimension $\geq 20$ corresponding to 54 mutation classes of rigid maximally mutable Laurent polynomials. From the point of view of…

代数几何 · 数学 2022-06-15 Liana Heuberger

We show that Fano 4-folds with Picard number 5 have Lefschetz defect 3 if and only if they are toric of combinatorial type K. We also find a characterization for such varieties in terms of Picard number of prime divisors. Moreover, we…

代数几何 · 数学 2020-07-22 Eleonora Anna Romano