English
Related papers

Related papers: On the valuative Nagata conjecture

200 papers

We prove that the Seshadri constant of a polarized abelian variety is equal to the Seshadri constant of its abelian subvariety if the Seshadri constant is relatively small with respect to its degree, or it contains an abelian divisor which…

Algebraic Geometry · Mathematics 2022-05-27 Rikito Ohta

We prove two new results for Seshadri constants on surfaces of general type. Let $X$ be a surface of general type. In the first part, inspired by \cite{B-S}, we list the possible values for the multi-point Seshadri constant…

Algebraic Geometry · Mathematics 2019-05-27 Praveen Kumar Roy

In the present paper we are concerned with the possible values of Seshadri constants. While in general every positive rational number appears as the local Seshadri constant of some ample line bundle, we point out that for adjoint line…

Algebraic Geometry · Mathematics 2010-11-23 Thomas Bauer , Tomasz Szemberg

Schmidt's subspace theorem in terms of Seshadri constants for closed subschemes in subgeneral position has been already developed sharply. We derive our theorem for numerically equivalent ample divisors by dint of the above theory step by…

Number Theory · Mathematics 2025-06-16 GuanHeng Zhao

Let $X$ be a smooth projective surface with Picard number 1. Let $L$ be the ample generator of the N\'eron-Severi group of $X$. Given an integer $r\ge 2$, we prove lower bounds for the Seshadri constant of $L$ at $r$ general points in $X$.

Algebraic Geometry · Mathematics 2016-10-20 Krishna Hanumanthu

Let $X$ be a general hypersurface of degree $md$ in the weighted projective space with weights $1,1,1,m$ for some for $d\geq 2$ and $m\geq 3$. We prove that the Seshadri constant of the ample generator of the N\'eron-Severi space at a…

Algebraic Geometry · Mathematics 2020-12-07 Alex Küronya , Sönke Rollenske

In this article, we give a description of the closed cone of curves of the projective bundle $\mathbb{P}(E)$ over a smooth projective variety $X$. Using duality, we then calculate the nef cone of divisors in $\mathbb{P}(E)$ over some…

Algebraic Geometry · Mathematics 2022-08-19 Snehajit Misra , Nabanita Ray

We compute Seshadri constants of a torus equivariant nef vector bundle on a projective space satisfying certain conditions. As an application, we compute Seshadri constants of tangent bundles on projective spaces. We also consider…

Algebraic Geometry · Mathematics 2021-05-11 Jyoti Dasgupta , Bivas Khan , Aditya Subramaniam

We study lower bounds on Seshadri constants at arbitrary points on surfaces with Picard number 1.

Algebraic Geometry · Mathematics 2007-11-06 Tomasz Szemberg

We examine how the Seshadri constant of an ample line bundle at a very general point of an algebraic surface can carry important global geometric information about the surface. In particular, we obtain a numerical criterion for when a…

Algebraic Geometry · Mathematics 2007-05-23 Michael Nakamaye

Koll\'ar's conjecture states that a complex projective surface $S$ with quotient singularities and with $H^2(S,\bbQ)\cong \bbQ$ should be rational if its smooth part $S^0$ is simply connected. We confirm the conjecture under the additional…

Algebraic Geometry · Mathematics 2007-05-23 JongHae Keum

The main purpose of the note is to exclude the existence of certain submaximal curves in fake projective planes. This will lead to lower bounds on multipoint Seshadri constants of `fake' $\mathcal{O}(1)$ on fake projective planes.

Algebraic Geometry · Mathematics 2021-04-21 Piotr Pokora , Halszka Tutaj-Gasinska

In this note, we continue the study of Seshadri constants on blow-ups of Hirzebruch surfaces initiated in arXiv:2312.14555. Now we consider blow-ups of ruled surfaces more generally. We propose a conjecture for classifying all the negative…

Algebraic Geometry · Mathematics 2024-07-29 Krishna Hanumanthu , Cyril J. Jacob , Suhas B. N. , Amit Kumar Singh

Prompted by results of Guardo, Van Tuyl and the second author for lines in projective 3 space, we develop asymptotic upper bounds for the least degree of a homogeneous form vanishing to order at least m on a union of disjoint r dimensional…

Algebraic Geometry · Mathematics 2016-04-12 Marcin Dumnicki , Brian Harbourne , Tomasz Szemberg , Halszka Tutaj-Gasińska

Let $X$ be a smooth projective algebraic variety over a number field $k$ and $P$ in $X(k)$. In 2007, the second author conjectured that, in a precise sense, if rational points on $X$ are dense enough, then the best rational approximations…

Algebraic Geometry · Mathematics 2024-03-06 Brian Lehmann , David McKinnon , Matthew Satriano

This paper shows that Mustata-Nakamura's conjecture holds for pairs consisting of a smooth surface and a multiideal with a real exponent over the base field of positive characteristic. As corollaries, we obtain the ascending chain condition…

Algebraic Geometry · Mathematics 2020-03-11 Shihoko Ishii

Given an etale quotient q:X->Y of smooth projective varieties we relate the simple Seshadri constant of a line bundle M on Y with the multiple Seshadri constant of q*M in the points of the fiber. We apply this method to compute the Seshadri…

Algebraic Geometry · Mathematics 2007-05-23 Luis Fuentes Garcia

Let X_g=C^{(2)}_g be the second symmetric product of a very general curve of genus g. We reduce the problem of describing the ample cone on X_g to a problem involving the Seshadri constant of a point on X_{g-1}. Using this we recover a…

Algebraic Geometry · Mathematics 2007-05-23 J. Ross

We study the Seshadri constants on geometrically ruled surfaces. The unstable case is completely solved. Moreover, we give some bounds for the stable case. We apply these results to compute the Seshadri constant of the rational and elliptic…

Algebraic Geometry · Mathematics 2016-09-07 Luis Fuentes Garcia

We prove an analogue in higher dimensions of the classical Narasimhan-Seshadri theorem for strongly stable vector bundles of degree 0 on a smooth projective variety $X$ with a fixed ample line bundle $\Theta$. As applications, over fields…

Algebraic Geometry · Mathematics 2014-02-26 V. Balaji , A. J. Parameswaran