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We study the positivity of complete intersections of nef classes. We first give a sufficient and necessary characterization on the complete intersection classes which have hard Lefschetz property on a compact complex torus, equivalently, in…

Algebraic Geometry · Mathematics 2022-12-29 Jiajun Hu , Jian Xiao

Motivated by the classical Theorems of Picard and Siegel and their generalizations, we define the notion of an {\it essentially large} effective divisor and derive some of its geometric and arithmetic consequences. We then prove that on a…

Algebraic Geometry · Mathematics 2010-06-08 Gordon Heier , Min Ru

We develop the quantum Kodaira-Spencer theory on the elliptic curve and establish the corresponding higher genus B-model. We show that the partition functions of the higher genus B-model on the elliptic curve are almost holomorphic modular…

Quantum Algebra · Mathematics 2011-12-20 Si Li

We study the category Cstabm of measurable cones and measurable stable functions, which is a denotational model of an higher-order language with continuous probabilities and full recursion. We look at Cstabm as a model for discrete…

Logic in Computer Science · Computer Science 2018-05-03 Raphaëlle Crubillé

In this paper, we prove that an algebraic fiber space $f:X\to Y$ over a perfect field $k$ of characteristic $p>0$ with nef relative anti-canonical divisor $-K_{X/Y}$ splits into the product after taking the base change along a finite cover…

Algebraic Geometry · Mathematics 2023-08-30 Sho Ejiri

We prove that the description of cubic functors is a wild problem in the sense of the representation theory. On the contrary, we describe several special classes of such functors (2-divisible, weakly alternative, vector spaces and torsion…

Representation Theory · Mathematics 2007-05-23 Yuriy Drozd

A convex-polynomial is a convex combination of the monomials $\{1, x, x^2, \ldots\}$. This paper establishes that the convex-polynomials on $\mathbb R$ are dense in $L^p(\mu)$ and weak$^*$ dense in $L^\infty(\mu)$, precisely when…

Functional Analysis · Mathematics 2015-11-02 Nathan S. Feldman , Paul J. McGuire

We show that a pseudoeffective R-divisor has numerical dimension 0 if it is numerically trivial on a subvariety with ample normal bundle. This implies that the cycle class of a curve with ample normal bundle is big, giving an affirmative…

Algebraic Geometry · Mathematics 2013-12-05 John Christian Ottem

We solve Teissier's proportionality problem for transcendental nef classes over a compact K\"ahler manifold which says that the equality in the Khovanskii-Teissier inequalities hold for two nef and big classes if and only if the two classes…

Algebraic Geometry · Mathematics 2014-10-21 Jixiang Fu , Jian Xiao

Tile B-splines in $\mathbb{R}^d$ are defined as autoconvolutions of the indicators of tiles, which are special self-similar compact sets whose integer translates tile the space $\mathbb{R}^d$. These functions are not piecewise-polynomial,…

Functional Analysis · Mathematics 2022-12-27 Tatyana Zaitseva

Let $C$ be a smooth projective curve over $\mathbb C$. Let $n,d\geq 1$. Let $\mathcal Q$ be the Quot scheme parameterizing torsion quotients of the vector bundle $\mathcal O^n_C$ of degree $d$. In this article we study the nef cone of…

Algebraic Geometry · Mathematics 2020-07-02 Chandranandan Gangopadhyay , Ronnie Sebastian

In this note, we report on a work jointly done with C. Simpson on a generalization of Reznikov's theorem which says that the Chern-Simons classes and in particular the Deligne Chern classes (in degrees $> 1$) are torsion, of a flat vector…

Algebraic Geometry · Mathematics 2008-03-11 Jaya NN Iyer

We prove that the type A, level one, conformal blocks divisors on $\bar{M}_{0,n}$ span a finitely generated, full-dimensional subcone of the nef cone. Each such divisor induces a morphism from $\bar{M}_{0,n}$, and we identify its image as a…

Algebraic Geometry · Mathematics 2011-05-18 Noah Giansiracusa , Angela Gibney

We consider the class of smooth convex functions defined over an open convex set. We show that this class is essentially different than the class of smooth convex functions defined over the entire linear space by exhibiting a function that…

Optimization and Control · Mathematics 2019-01-01 Yoel Drori

In this paper we propose an algorithm for exact partitioning of high-order models. We define a general class of $m$-degree Homogeneous Polynomial Models, which subsumes several examples motivated from prior literature. Exact partitioning…

Machine Learning · Computer Science 2022-10-04 Chuyang Ke , Jean Honorio

We study aisles in the derived category of a hereditary abelian category. Given an aisle, we associate a sequence of subcategories of the abelian category by considering the different homologies of the aisle. We then obtain a sequence,…

Category Theory · Mathematics 2012-02-23 Donald Stanley , Adam-Christiaan van Roosmalen

Given an invertible sheaf, does it come from a Cartier divisor? This might fail in presence of embedded components. I give some examples and characterize those invertible sheaves that allow a Cartier divisor.

Algebraic Geometry · Mathematics 2007-05-23 Stefan Schroeer

We introduce Seshadri constants for line bundles in a relative setting. They generalize the classical Seshadri constants of line bundles on projective varieties and their extension to vector bundles studied by Beltrametti-Schneider-Sommese…

Algebraic Geometry · Mathematics 2019-03-06 Mihai Fulger , Takumi Murayama

We prove the Cone Theorem for algebraically integrable foliations. As a consequence, we show that termination of flips implies the b-nefness of the moduli part of a log canonical pair with respect to a contraction, generalising the case of…

Algebraic Geometry · Mathematics 2022-03-03 Florin Ambro , Paolo Cascini , Vyacheslav Shokurov , Calum Spicer

On a projective surface it is well-known that the set of curves orthogonal to a nef line bundle is either finite or uncountable. We show that this dichotomy fails in higher dimension by constructing a nef line bundle on a threefold which is…

Algebraic Geometry · Mathematics 2014-10-17 John Lesieutre , John Christian Ottem