English
Related papers

Related papers: Partially ample line bundles and base loci

200 papers

Let $f:X \to S$ be a projective morphism of noetherian schemes and let $L$ be an invertible sheaf on $X$. We show that the relative augmented base locus of $L$ coincides with the relative exceptional locus of $L$. We also prove a…

Algebraic Geometry · Mathematics 2023-08-08 Yusuke Ushiro

We determine all of lines in the moduli space $M$ of stable bundles for arbitrary rank and degree. A further application of minimal rational curves is also given in last section.

Algebraic Geometry · Mathematics 2015-05-13 Ngaiming Mok , Xiaotao Sun

We explain how to define an embedding of a tame stack over a noetherian ring into a certain generalization of a weighted projective stack using a notion of ample vector bundle on the stack. As applications we construct algebraic moduli…

Algebraic Geometry · Mathematics 2024-07-03 Daniel Bragg , Martin Olsson , Rachel Webb

We study the linearization of line bundles and the local structure of actions of connected linear algebraic groups, in the setting of seminormal varieties. We show that several classical results about normal varieties extend to that…

Algebraic Geometry · Mathematics 2014-10-22 Michel Brion

Very ampleness criteria for rank 2 vector bundles over smooth, ruled surfaces over rational and elliptic curves are given. The criteria are then used to settle open existence questions for some special threefolds of low degree.

Algebraic Geometry · Mathematics 2009-02-23 Alberto Alzati , GianMario Besana

We study the positivity of an Ulrich vector bundle defined with respect to a globally generated ample line bundle. First we prove a generalization of a Lopez theorem on the first Chern class and the bigness of an Ulrich bundle. Then, under…

Algebraic Geometry · Mathematics 2024-03-06 Valerio Buttinelli

Fujino gave a proof in [Fuj03] for the semi-ampleness of the moduli part in the canonical bundle formula in the case when the general fibers are K3 surfaces or Abelian varieties. We show a similar statement when the general fibers are…

Algebraic Geometry · Mathematics 2024-05-10 Hyunsuk Kim

Given a finite volume hyperbolic surface, a fundamental polygon and an oriented closed geodesic, we associate a partial covering of the surface. We prove that given a sequence of collections of oriented closed geodesics equidistributing in…

Geometric Topology · Mathematics 2025-02-13 Asbjørn Christian Nordentoft , Ser Peow Tan

We study ample stable vector bundles on minimal rational surfaces. We give a complete classification of those moduli spaces for which the general stable bundle is both ample and globally generated. We also prove that if $V$ is any stable…

Algebraic Geometry · Mathematics 2021-07-22 Jack Huizenga , John Kopper

We generalize the van Kampen theorem for unions of non-connected spaces, due to R. Brown and A. R. Salleh, to the context where families of subspaces of a space B are replaced by a locally sectionable map to B.

Algebraic Topology · Mathematics 2024-12-05 Ronald Brown , George Janelidze , George Peschke

In this paper we solve a problem posed by H. Bommier-Hato, M. Engli\v{s} and E.H. Youssfi in [3] on the boundedness of the Bergman-type projections in generalized Fock spaces. It will be a consequence of two facts: a full description of the…

Complex Variables · Mathematics 2017-12-15 Carme Cascante , Joan Fàbrega , Daniel Pascuas

We introduce a class of semipositive metrics on ample line bundles in non-Archimedean geometry, called Shilov finite metrics. We calculate the determinant metric distorsion in the exact sequence induced by a global section using…

Algebraic Geometry · Mathematics 2025-12-01 Yanbo Fang

We provide two new characterizations of bounded orthogonally additive polynomials from a uniformly complete vector lattice into a convex bornological space using harmonic means and completely partitioned weighted geometric means. Our result…

Functional Analysis · Mathematics 2021-09-23 Christopher Schwanke

We address two questions related to the semiampleness of line bundles arising from Hodge theory. First, we prove there is a functorial compactification of the image of a period map of a polarizable integral pure variation of Hodge…

Algebraic Geometry · Mathematics 2025-12-19 Benjamin Bakker , Stefano Filipazzi , Mirko Mauri , Jacob Tsimerman

Let $X$ be a projective variety over a field. In this paper, we will construct a moduli space of very ample line bundles on $X$. In doing so, we develop a generalization of Fitting ideals to complexes of sheaves on $X$. We give other…

Algebraic Geometry · Mathematics 2025-08-01 Brian Nugent

A recent paper of Totaro develops a theory of $q$-ample bundles in characteristic 0. Specifically, a line bundle $L$ on $X$ is $q$-ample if for every coherent sheaf $\mathcal{F}$ on $X$, there exists an integer $m_0$ such that $m\geq m_0$…

Algebraic Geometry · Mathematics 2019-02-20 Morgan V Brown

In this paper we study the distribution of successive minima of global sections of powers of a metrized ample line bundle on a variety over a number field. We develop criteria for there to exist a measure on the real line describing the…

Algebraic Geometry · Mathematics 2020-01-14 T. Chinburg , Q. Guignard , C. Soulé

Part B (of a project involving four Parts) is about "bases of lines", a concept introduced by C. Herrmann and the author in the late 80's. Bases of lines attempt to describe a given modular lattice in a geometric way akin to how projective…

Combinatorics · Mathematics 2022-02-10 Marcel Wild

This is Part A of four Parts dedicated to modular lattices of finite length. It builds on 1992 notes of the author (available on ResearchGate), and in so doing heeds a wish of the late Gian-Carlo Rota. Part A is in fairly final form and…

Combinatorics · Mathematics 2024-12-09 Marcel Wild

The concept of full points of abstract unitals has been introduced by Korchm\'aros, Siciliano and Sz\H{o}nyi as a tool for the study of projective embeddings of abstract unitals. In this paper we give a more detailed description of the…

Combinatorics · Mathematics 2019-06-26 Dávid Mezőfi , Gábor P. Nagy