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Related papers: Kawamata boundedness for Fano threefolds and the G…

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We show that for a $\mathbb Q$-factorial canonical Fano $3$-fold $X$ of Picard number $1$, $(-K_X)^3\leq 72$. The main tool is a Kawamata--Miyaoka type inequality which relates $(-K_X)^3$ with $\hat{c}_2(X)\cdot c_1(X)$, where…

Algebraic Geometry · Mathematics 2025-11-20 Chen Jiang , Haidong Liu , Jie Liu

Studying Manin's program for a family of spherical log Fano threefolds, we determine the asymptotic number of integral points whose height associated with an arbitrary ample line bundle is bounded. This confirms a recent conjecture by…

Number Theory · Mathematics 2025-05-16 Ulrich Derenthal , Florian Wilsch

We give the multiplicity of terminal singularities on threefolds by simple calculation. Then we obtain the best inequalities for the multiplicity and the index. By using this, we can improve the boundedness number of terminal weak Q-Fano…

Algebraic Geometry · Mathematics 2007-05-23 Nobuyuki Kakimi

We construct well-formed and quasismooth terminal Fano 4-folds of index 1 in low codimension containing at worst isolated orbifold points. We provide a certain classification of these varieties where their images under the anitcanonical…

Algebraic Geometry · Mathematics 2025-06-30 Muhammad Imran Qureshi

We consider Fano threefolds $X$ with canonical Gorenstein singularities. Under additional assumption that $X$ has at least one non-cDV point we prove a sharp bound of the degree: $-K_X^3\le 72$.

Algebraic Geometry · Mathematics 2010-05-12 Yuri G. Prokhorov

T.Kishimoto raised the problem to classify all compactifications of contractible affine 3-folds into smooth Fano 3-folds with second Betti number two and classified such compactifications whose log canonical divisors are not nef. In this…

Algebraic Geometry · Mathematics 2017-08-10 Masaru Nagaoka

We discuss various results on Hilbert schemes of lines and conics and automorphism groups of smooth Fano threefolds with Picard rank 1. Besides a general review of facts well known to experts, the paper contains some new results, for…

Algebraic Geometry · Mathematics 2018-09-05 Alexander Kuznetsov , Yuri Prokhorov , Constantin Shramov

In this paper, we study the explicit geometry of threefolds, in particular, Fano varieties. We find an explicitly computable positive integer $N$, such that all but a bounded family of Fano threefolds have $N$-complements. This result has…

Algebraic Geometry · Mathematics 2023-11-14 Caucher Birkar , Jihao Liu

We announce the classification of Sato-Tate groups of abelian threefolds over number fields; there are 410 possible conjugacy classes of closed subgroups of USp(6) that occur. We summarize the key points of the "upper bound" aspect of the…

Number Theory · Mathematics 2021-12-15 Francesc Fité , Kiran S. Kedlaya , Andrew V. Sutherland

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…

Algebraic Geometry · Mathematics 2019-08-26 Brian Lehmann , Sho Tanimoto

We show that 3-braid links with given (non-zero) Alexander or Jones polynomial are finitely many, and can be effectively determined. We classify among closed 3-braids strongly quasipositive and fibered ones, and show that 3-braid links have…

Geometric Topology · Mathematics 2007-10-10 A. Stoimenow

We prove that the degree of Fano threefolds with terminal Q-factorial singularities and Picard number one is at most 125/2 and the bound is sharp.

Algebraic Geometry · Mathematics 2010-04-26 Yu. G. Prokhorov

An inductive approach to classifying toric Fano varieties is given. As an application of this technique, we present a classification of the toric Fano threefolds with at worst canonical singularities. Up to isomorphism, there are 674,688…

Algebraic Geometry · Mathematics 2019-08-15 Alexander M. Kasprzyk

We describe an infinite set of smooth projective threefolds that have equivalent derived categories but are not isomorphic, contrary to a conjecture of Kawamata. These arise as blow-ups of $\mathbb P^3$ at various configurations of 8…

Algebraic Geometry · Mathematics 2013-11-04 John Lesieutre

We show that elliptic Calabi--Yau threefolds form a bounded family. We also show that the same result holds for minimal terminal threefolds of Kodaira dimension 2, upon fixing the rate of growth of pluricanonical forms and the degree of a…

Algebraic Geometry · Mathematics 2025-08-04 Stefano Filipazzi , Christopher D. Hacon , Roberto Svaldi

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.

Algebraic Geometry · Mathematics 2009-12-14 Carla Novelli , Gianluca Occhetta

We give an elementary argument to compute the $\alpha$-invariant of this Fano 3-fold, which implies the existence of a Kahler-Einstein metric.

Differential Geometry · Mathematics 2007-11-29 S. K. Donaldson

We explicitly fully describe the K-moduli space of Fano threefold family number 3.3. We first show that K-semistable Fano varieties with volume greater than 18 are Gorenstein canonical and admit general elephants, decreasing the bound on a…

Algebraic Geometry · Mathematics 2025-10-16 Erroxe Etxabarri-Alberdi , James Matthew Jones , Theodoros Stylianos Papazachariou

We prove an optimal Kawamata-Miyaoka-type inequality for terminal $\mathbb Q$-Fano threefolds with Fano index at least $3$. As an application, any terminal $\mathbb Q$-Fano threefold $X$ satisfies the following Kawamata-Miyaoka-type…

Algebraic Geometry · Mathematics 2026-05-27 Haidong Liu , Jie Liu

This paper is an attempt for the classification of polarized manifolds of sectional genus $g=3$ and dimension $n\geq 3$. As in the case of $g\leq 2$,which was classified by T.Fujita,we use Mori-Kawamata theory. The classification result of…

alg-geom · Mathematics 2008-02-03 Hironobu Ishihara