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Related papers: Conic bundle structures on Q-Fano threefolds

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In this article, we prove that any Q-Calabi-Yau 3-fold with only ordinary terminal singularities and any Q-Fano 3-fold of Fano index 1 with only terminal singularities have Q-smoothings.

Algebraic Geometry · Mathematics 2007-05-23 Tatsuhiro Minagawa

We study Fano threefolds that can be obtained by blowing up the three-dimensional projective space along a smooth curve of degree six and genus three. We produce many new K-stable examples of such threefolds, and we describe all finite…

Algebraic Geometry · Mathematics 2024-04-12 Ivan Cheltsov , Oliver Li , Sione Ma'u , Antoine Pinardin

We study the rationality of some geometrically rational three-dimensional conic and quadric surface bundles, defined over the reals and more general real closed fields, for which the real locus is connected and the intermediate Jacobian…

Algebraic Geometry · Mathematics 2026-04-22 Olivier Benoist , Alena Pirutka

We prove that a quasi-smooth Fano threefold hypersurface is birationally rigid if and only if it has Fano index one.

Algebraic Geometry · Mathematics 2020-07-29 Hamid Ahmadinezhad , Ivan Cheltsov , Jihun Park

We prove that any Fano manifold of coindex three admitting nef tangent bundle is homogeneous.

Algebraic Geometry · Mathematics 2019-04-24 Kiwamu Watanabe

In this paper, we prove the Bogomolov-Gieseker type inequality conjecture for threefolds with nef tangent bundles. As a corollary, there exist Bridgeland stability conditions on these threefolds.

Algebraic Geometry · Mathematics 2020-07-28 Naoki Koseki

We give a proof of Mukai's Theorem on the existence of certain exceptional vector bundles on prime Fano threefolds. To our knowledge this is the first complete proof in the literature. The result is essential for Mukai's biregular…

Algebraic Geometry · Mathematics 2025-09-26 Arend Bayer , Alexander Kuznetsov , Emanuele Macrì

The authors give a complete classification of projective threefolds admitting a holomorphic conformal structure. A Corollary is the complete list of projective threefolds, whose tangent bundle is a symmetric square.

Algebraic Geometry · Mathematics 2007-05-23 Priska Jahnke , Ivo Radloff

We prove the boundedness theorem for Fano threefolds with log-terminal singularities of any fixed index. This is an improvement of our earlier result, where we required additionally that the variety is Q-factorial, with Picard number 1. The…

Algebraic Geometry · Mathematics 2007-05-23 Alexandr Borisov

We construct a hyperbolic three-manifold with trivial finite type invariants up to a given degree.

Geometric Topology · Mathematics 2007-05-23 Hitoshi Murakami

We prove that a smooth complex projective threefold with a K\"ahler metric of negative holomorphic sectional curvature has ample canonical line bundle. In dimensions greater than three, we prove that, under equal assumptions, the nef…

Algebraic Geometry · Mathematics 2009-09-02 Gordon Heier , Steven S. Y. Lu , Bun Wong

We develop an equivariant version of the formalism of intermediate Jacobian torsor obstructions, and apply it to conic bundles over rational surfaces, quadric surface bundles over $\mathbb P^1$, and Fano threefolds.

Algebraic Geometry · Mathematics 2025-03-20 Tudor Ciurca , Sho Tanimoto , Yuri Tschinkel

In a work of Costa and Mir\'{o}-Roig state the following conjecture: Every smooth complete toric Fano variety has a full strongly exceptional collection of line bundles. The goal of this article is to prove it for toric Fano 3-folds.

Algebraic Geometry · Mathematics 2010-12-30 Alessandro Bernardi , Sofia Tirabassi

This paper describes the structure of singular codimension one foliations with numerically trivial canonical bundle on projective manifolds.

Algebraic Geometry · Mathematics 2017-12-29 Frank Loray , Jorge Vitorio Pereira , Frederic Touzet

We study stable rationality properties of conic bundles over rational surfaces.

Algebraic Geometry · Mathematics 2015-03-31 Brendan Hassett , Andrew Kresch , Yuri Tschinkel

We generalize the equivariant intermediate Jacobian torsor obstruction over $\mathbb{C}$ to algebraically closed fields of characteristic zero. It is an obstruction to the (projective) linearizability problem of finite group actions on…

Algebraic Geometry · Mathematics 2026-01-13 Shuto Abe

The existence of essential closed surfaces surfaces is proven for finite coverings of 3-manifolds that are triangulated by finitely many topological ideal tetrahedra and admit a regular, negatively curved, ideal structure.

Geometric Topology · Mathematics 2021-09-03 Charalampos Charitos

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…

Algebraic Geometry · Mathematics 2019-06-26 Pedro Montero , Eleonora Anna Romano

In this note we prove that any toric Fano manifold with nef tangent bundle is a product of projective spaces. In particular, it implies that Campana-Peternell conjecture hold for toric manifolds.

Algebraic Geometry · Mathematics 2015-06-19 Qilin Yang

In this article, we prove that if $X$ is a complex manifold of dimension $n\geq 4$ such that there exists a $q$-convex with corners function $f\in F_{q}(X)$, then every holomorphic line bundle over $\{f>c\}$ extends uniquely to $X$ if…

Complex Variables · Mathematics 2026-01-15 Youssef Alaoui