中文
相关论文

相关论文: Fano congruences of index $3$ and alternating $3$-…

200 篇论文

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 study the deformation theory of the Fano scheme $\mathrm{F}=\mathrm{F}(\mathrm{X})$ of lines on a cubic $\mathrm{X}$ of dimension $d$ with only finitely many singularities. By taking the relative Fano scheme, we define a morphism…

代数几何 · 数学 2025-09-30 Samuel Stark

Let X be a Fano manifold of dimension n and index n-3. Kawamata proved the non vanishing of the global sections of the fundamental divisor in the case n=4. Moreover he proved that if Y is a general element of the fundamental system then Y…

代数几何 · 数学 2012-01-12 Enrica Floris

A Fano-Enriques threefold is a three-dimensional non-Gorenstein Fano variety of index 1 with at most canonical singularities. We study the birational geometry of Fano-Enriques threefolds with terminal cyclic quotient singularities. We…

代数几何 · 数学 2023-01-19 Arman Sarikyan

We show that mixed-characteristic and equi-characteristic small deformations of 3-dimensional canonical (resp. terminal) singularities with perfect residue field of characteristic $p>5$ are canonical (resp. terminal). We discuss…

代数几何 · 数学 2024-03-08 Fabio Bernasconi , Iacopo Brivio , Stefano Filipazzi

We prove that Generalized Mukai Conjecture holds for Fano manifolds $X$ of pseudoindex $i_X \ge (\dim X +3)/3$. We also give different proofs of the conjecture for Fano fourfolds and fivefolds.

代数几何 · 数学 2009-12-14 Carla Novelli , Gianluca Occhetta

Let X be a Fano variety of dimension n, pseudoindex i_X and Picard number \rho_X. A generalization of a conjecture of Mukai says that \rho_X(i_X-1)\le n. We prove that the conjecture holds if: a) X has pseudoindex i_X \ge \frac{n+3}{3} and…

代数几何 · 数学 2007-05-23 Marco Andreatta , Elena Chierici , Gianluca Occhetta

A generalization of S. Mukai's conjecture says that if $X$ is a Fano $n$-fold with Picard number $\rho_X$ and pseudo-index $i_X$, then $\rho_X(i_X-1) \leq n$, with equality if and only if $X \cong (\mathbb{P}^{i_X-1})^{\rho_X}$. In this…

代数几何 · 数学 2017-03-23 Taku Suzuki

In this paper we prove that any smooth prime Fano threefold, different from the Mukai-Umemura threefold, contains a 1-dimensional family of intersecting lines. Combined with a result of the second author (see J. Algebr. Geom. 8:2 (1999),…

代数几何 · 数学 2007-05-23 Atanas Iliev , Carmen Schuhmann

We study arithmetic finiteness of prime Fano threefolds of genus 7 and their higher dimensional generalization, called Mukai varieties of genus 7. For prime Fano threefolds of genus 7, we provide an arithmetic refinement of the Torelli…

代数几何 · 数学 2025-10-02 Tetsushi Ito , Akihiro Kanemitsu , Teppei Takamatsu , Yuuji Tanaka

By the description due to Mukai and Iliev, a smooth prime Fano threefold X of genus 9 is associated to a surface P(V), ruled over a smooth plane quartic Gamma. We use Kuznetsov's integral functor to study rank-2 stable sheaves on X with odd…

代数几何 · 数学 2014-11-03 Maria Chiara Brambilla , Daniele Faenzi

We propose Gamma Conjectures for Fano manifolds which can be thought of as a square root of the index theorem. Studying the exponential asymptotics of solutions to the quantum differential equation, we associate a principal asymptotic class…

代数几何 · 数学 2021-06-02 Sergey Galkin , Vasily Golyshev , Hiroshi Iritani

We give a self-contained and simplified proof of Mukai's classification of prime Fano threefolds of index 1 and genus $g \ge 6$ with at most Gorenstein factorial terminal singularities, and of its extension to higher-dimension.

代数几何 · 数学 2025-07-01 Arend Bayer , Alexander Kuznetsov , Emanuele Macrì

As a generalization of the Mukai conjecture, we conjecture that the Fano manifolds $X$ which satisfy the property $\rho_X(r_X-1)\geq\dim X-1$ have very special structure, where $\rho_X$ is the Picard number of $X$ and $r_X$ is the index of…

代数几何 · 数学 2015-04-03 Kento Fujita

We study the moduli spaces of rational curves on prime Fano threefolds of index 1. For general threefolds of most genera we compute the dimension and the number of irreducible components of these moduli spaces. Our results confirm Geometric…

代数几何 · 数学 2019-08-26 Brian Lehmann , Sho Tanimoto

We consider Fano sevenfolds $Y$ obtained by intersecting the Grassmannian $\hbox{Gr}(3,6)$ with a codimension 2 linear subspace (with respect to the Pl\"ucker embedding). We prove that the motive of $Y$ is Kimura finite-dimensional. We also…

代数几何 · 数学 2021-05-17 Robert Laterveer

Let $X$, $Y$ be Fano threefolds of Picard number one and such that the ample generators of Picard groups are very ample. Let $X$ be of index one and $Y$ be of index two. It is shown that the only morphisms from $X$ to $Y$ are double…

代数几何 · 数学 2007-05-23 Ekaterina Amerik

A V_{12} Fano threefold is a smooth Fano threefold X of index 1 with Pic X = Z and (-K_X)^3=12. We show that the bounded derived category of coherent sheaves on any V_{12} threefold X admits a semiorthogonal decomposition consisting of two…

代数几何 · 数学 2007-05-23 Alexander Kuznetsov

We study Q-factorial terminal Fano 3-folds whose equations are modelled on those of the Segre embedding of P^2 x P^2. These lie in codimension 4 in their total anticanonical embedding and have Picard rank 2. They fit into the current state…

代数几何 · 数学 2021-12-17 Gavin Brown , Alexander Kasprzyk , Muhammad Imran Qureshi

Let X be a Fano variety of index k such that the non-klt locus Nklt(X) is not empty. We prove that Nklt(X) has dimension at least k-1 and equality holds if and only if Nklt(X) is a linear projective space P^{k-1}. In this case X has lc…

代数几何 · 数学 2017-10-24 Mauro C. Beltrametti , Andreas Höring , Carla Novelli