English
Related papers

Related papers: Weak approximation for Fano complete intersections…

200 papers

We solve the convergence case of the generalized Baker-Schmidt problem for simultaneous approximation on affine subspaces, under natural diophantine type conditions. In one of our theorems, we do not require monotonicity on the…

Number Theory · Mathematics 2020-01-08 Jing-Jing Huang , Jason J. Liu

In this paper we prove that badly approximable points on any analytic non-degenerate curve in $\mathbb{R}^n$ is an absolute winning set. This confirms a key conjecture in the area stated by Badziahin and Velani (2014) which represents a…

Number Theory · Mathematics 2020-12-24 Victor Beresnevich , Erez Nesharim , Lei Yang

Fano varieties are subvarieties of the Grassmannian whose points parametrize linear subspaces contained in a given projective variety. These expository notes give an account of results on Fano varieties of complete intersections, with a…

Algebraic Geometry · Mathematics 2012-12-05 Paul Larsen

Denote by $E_r$ the $r^{th}$ elementary symmetric polynomial in $\dim V$ variables for a vector space $V$ over an infinite field $\Bbbk$. We describe the rational points on the Fano scheme $F_{d-1}(Z(E_{\dim V-1}))$ of projective…

Algebraic Geometry · Mathematics 2025-08-06 Alexandru Chirvasitu

We establish the convergence theory of multiplicative Diophantine approximation for all non-degenerate, smooth manifolds. We also settle said convergence theory for all affine subspaces satisfying a highly generic and essentially optimal…

Number Theory · Mathematics 2026-02-12 Sam Chow , Rajula Srivastava , Niclas Technau , Han Yu

We characterise smooth curves in P^3 whose blow-up produces a threefold with anticanonical divisor big and nef. These are curves C of degree d and genus g lying on a smooth quartic, such that (i) $4d-30 \le g\le 14$ or $(g,d) = (19,12)$,…

Algebraic Geometry · Mathematics 2013-03-22 Jérémy Blanc , Stéphane Lamy

In this paper we investigate Fano manifolds $X$ whose Chern characters $ch_k(X)$ satisfy some positivity conditions. Our approach is via the study of polarized minimal families of rational curves $(H_x,L_x)$ through a general point $x\in…

Algebraic Geometry · Mathematics 2009-07-01 Carolina Araujo , Ana-Maria Castravet

We prove $f$-positivity of $\mathcal{O}_X(1)$ for arbitrary dimension fibrations over curves $f\colon X\to B$ whose general fibre is a complete intersection. In the special case where the family is a global complete intersection, we prove…

Algebraic Geometry · Mathematics 2023-12-29 Miguel Angel Barja , Lidia Stoppino

The goal of this short note is to point out that every Fano manifold with a nef tangent bundle possesses an almost K{\"a}hler-Einstein metric, in a weak sense. The technique relies on a regularization theorem for closed positive (1,…

Complex Variables · Mathematics 2018-02-07 Jean-Pierre Demailly

Katona's intersection theorem states that every intersecting family $\mathcal F\subseteq[n]^{(k)}$ satisfies $\vert\partial\mathcal F\vert\geq\vert\mathcal F\vert$, where $\partial\mathcal F=\{F\setminus x:x\in F\in\mathcal F\}$ is the…

Combinatorics · Mathematics 2022-06-10 Marcelo Sales , Bjarne Schülke

In this paper, an update on the classification of smooth weak Fano threefolds with Picard number two and small anti-canonical maps is given. Geometric constructions are provided for previously open numerical cases by blowing up certain…

Algebraic Geometry · Mathematics 2025-01-22 Joseph Cutrone , Nicholas Marshburn

We study strong approximation for the intersection of two affine quadrics. As its application, we prove the fibration method for weak approximation over number fields of rank four with nonsplit fibers split by quadratic extensions.

Algebraic Geometry · Mathematics 2025-11-07 Dasheng Wei , Jie Xu , Yi Zhu

Consider a smooth log Fano variety over the function field of a curve. Suppose that the boundary has positive normal bundle. Choose an integral model over the curve. Then integral points are Zariski dense, after removing an explicit finite…

Algebraic Geometry · Mathematics 2009-11-13 Brendan Hassett , Yuri Tschinkel

For the class of de Branges-Rovnyak spaces $\mathcal{H}(b)$ of the unit disk $\mathbb{D}$ defined by extreme points $b$ of the unit ball of $H^\infty$, we study the problem of approximation of a general function in $\mathcal{H}(b)$ by a…

Functional Analysis · Mathematics 2021-08-20 Adem Limani , Bartosz Malman

Let $X$ be a K3 surface with Picard number 1 and genus $g$, such that $g\not\equiv 3 \mod 4$. In this paper, we show that $X$ is a Fano visitor, i.e., there is a smooth Fano variety $Y$ and an embedding $D^b(X)\hookrightarrow D^b(Y)$ given…

Algebraic Geometry · Mathematics 2025-05-08 Anibal Aravena

We propose a new algorithm that finds an $\varepsilon$-approximate fixed point of a smooth function from the $n$-dimensional $\ell_2$ unit ball to itself. We use the general framework of finding approximate solutions to a variational…

Computer Science and Game Theory · Computer Science 2025-01-22 Idan Attias , Yuval Dagan , Constantinos Daskalakis , Rui Yao , Manolis Zampetakis

In the first part of this article, we give bounds on self-intersections $C^2$ of integral curves $C$ on blow-ups $Bl_nX$ of surfaces $X$ with the anti-cannonical divisor $-K_X$ effective. In the last part, we prove the weak bounded…

Algebraic Geometry · Mathematics 2024-08-28 Snehajit Misra , Nabanita Ray

We prove birational superrigidity of every hypersurface of degree N in P^N with singular locus of dimension s, under the assumption that N is at least 2s+8 and it has only quadratic singularities of rank at least N-s. Combined with the…

Algebraic Geometry · Mathematics 2016-06-23 Fumiaki Suzuki

We approximate intersection numbers $\big\langle \psi_1^{d_1}\cdots \psi_n^{d_n}\big\rangle_{g,n}$ on Deligne-Mumford's moduli space $\overline{\mathcal M}_{g,n}$ of genus $g$ stable complex curves with $n$ marked points by certain…

Geometric Topology · Mathematics 2020-10-19 Vincent Delecroix , Élise Goujard , Peter Zograf , Anton Zorich

Given a finite set $X$ of points in $R^n$ and a family $F$ of sets generated by the pairs of points of $X$, we determine volumetric and structural conditions for the sets that allow us to guarantee the existence of a positive-fraction…

Metric Geometry · Mathematics 2016-08-22 Alexander Magazinov , Pablo Soberón