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We exhibit full exceptional collections of vector bundles on any smooth, Fano arithmetic toric variety whose split fan is centrally symmetric.

Algebraic Geometry · Mathematics 2020-06-17 Matthew R Ballard , Alexander Duncan , Patrick K. McFaddin

We prove that the derived category of a smooth complete intersection variety is equivalent to a full subcategory of the derived category of a smooth projective Fano variety. This enables us to define some new invariants of smooth projective…

Algebraic Geometry · Mathematics 2015-04-30 Young-Hoon Kiem , In-Kyun Kim , Hwayoung Lee , Kyoung-Seog Lee

We characterize the birational geometry of some hyperk\"ahler fourfolds of Picard rank $3$ obtained as the Fano varieties of lines on cubic fourfolds containing pairs of cubic scrolls. In each of the two cases considered, we identify all of…

Algebraic Geometry · Mathematics 2025-09-10 Corey Brooke , Sarah Frei , Lisa Marquand , Xuqiang Qin

We study the cones of q-ample divisors on smooth complex varieties. In favourable cases, we identify a part where the closure of this cone and the nef cone have the same boundary. This is especially interesting for Fano (or almost Fano)…

Algebraic Geometry · Mathematics 2016-02-17 Robert Laterveer

The anticanonical complex generalizes the Fano polytope from toric geometry and has been used to study Fano varieties with torus action so far. We work out the case of complete intersections in toric varieties defined by non-degenerate…

Algebraic Geometry · Mathematics 2025-07-01 Juergen Hausen , Christian Mauz , Milena Wrobel

We prove that a smooth well formed Fano weighted complete intersection of codimension 2 has a nef partition. We discuss applications of this fact to Mirror Symmetry. In particular we list all nef partitions for smooth well formed Fano…

Algebraic Geometry · Mathematics 2020-08-13 Victor Przyjalkowski , Constantin Shramov

We construct new families of smooth Fano fourfolds with Picard rank 1, which contain cylinders, i.e., Zariski open subsets of form $Z\times A^1$, where $Z$ is a quasiprojective variety. The affine cones over such a fourfold admit effective…

Algebraic Geometry · Mathematics 2015-07-08 Yuri Prokhorov , Mikhail Zaidenberg

We prove that every quasi-smooth hypersurface in the 95 families of weighted Fano threefold hypersurfaces is birationally rigid.

Algebraic Geometry · Mathematics 2017-02-14 Ivan Cheltsov , Jihun Park

We study Fano varieties endowed with a faithful action of a symmetric group, as well as analogous results for Calabi--Yau varieties, and log terminal singularities. We show the existence of a constant $m(n)$, so that every symmetric group…

Algebraic Geometry · Mathematics 2025-02-05 Louis Esser , Lena Ji , Joaquín Moraga

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…

Algebraic Geometry · Mathematics 2023-01-18 Tiago Duarte Guerreiro

We prove birational superrigidity of generic Fano complete intersections $V$ of type $2^{k_1}\cdot 3^{k_2}$ in the projective space ${\mathbb P}^{2k_1+3k_2}$, under the condition that $k_2\geq 2$ and $k_1+2k_2=\mathop{\rm dim} V\geq 12$,…

Algebraic Geometry · Mathematics 2015-06-05 Aleksandr Pukhlikov

Using ideas from the theory of tropical curves and degeneration, we prove that any Fano hypersurface (and more generally Fano complete intersections) is swept by at most quadratic rational curves.

Algebraic Geometry · Mathematics 2011-08-23 Takeo Nishinou

The symmetric projective varieties of rank one are all smooth and Fano by a classic result of Akhiezer. We classify the locally factorial (respectively smooth) projective symmetric $G$-varieties of rank 2 which are Fano. When $G$ is…

Algebraic Geometry · Mathematics 2010-12-22 Alessandro Ruzzi

We complete the study of birational geometry of Fano fiber spaces $\pi\colon V\to {\mathbb P}^1$, the fiber of which is a Fano double hypersurface of index 1. For each family of these varieties we either prove birational rigidity or produce…

Algebraic Geometry · Mathematics 2015-06-26 Aleksandr V. Pukhlikov

We classify Q-factorial Gorenstein Fano non-degenerate complete intersection threefolds in fake weighted projective spaces.

Algebraic Geometry · Mathematics 2025-10-14 Juergen Hausen , Paul Weiss

We give several examples of pairs of non-isomorphic cubic fourfolds whose Fano varieties of lines are birationally equivalent (and in one example isomorphic). Two of our examples, which are special families of conjecturally irrational…

Algebraic Geometry · Mathematics 2024-12-20 Corey Brooke , Sarah Frei , Lisa Marquand

We study the Picard variety of the Fano surface of nodal and mildly cuspidal cubic threefolds in arbitrary characteristic by relating divisors on the Fano surface to divisors on the symmetric product of a curve of genus 4.

Algebraic Geometry · Mathematics 2010-10-12 Gerard van der Geer , Alexis Kouvidakis

We study birational transformations into elliptic fibrations and birational automorphisms of quasismooth anticanonically embedded weighted Fano 3-fold hypersurfaces having terminal singularities classified by A.R. Iano-Fletcher, J. Johnson,…

Algebraic Geometry · Mathematics 2007-05-23 Ivan Cheltsov , Jihun Park

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…

Algebraic Geometry · Mathematics 2007-05-23 Ivan Cheltsov , Constantin Shramov , Victor Przyjalkowski

In this note we study Fano threefolds with noncyclic torsion in the divisor class group. Since they can all be obtained as quotients of Fano threefolds, we get also all examples that can be obtained as quotients of low codimension Fanos in…

Algebraic Geometry · Mathematics 2007-06-14 Jorge Caravantes