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Related papers: Remark on nefness in higher codimension

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In this paper, we study the higher codimensional cycle structure of the Hilbert scheme of three points in the projective plane. In particular, we compute all Chern (and Segre) classes of all tautological bundles on it and compute the nef…

Algebraic Geometry · Mathematics 2021-11-04 Tim Ryan , Alexander Stathis

Let X be a (connected and reduced) complex space. A q-collar of X is a bounded domain whose boundary is a union of a strongly q-pseudoconvex, a strongly q-pseudoncave and two flat (i.e. locally zero sets of pluriharmonic functions)…

Complex Variables · Mathematics 2008-02-04 Alberto Saracco , Giuseppe Tomassini

Chapter 1 deals with the problem of the existence of an upper/lower envelope from a convex cone or, more generally, a convex set for functions on the projective limit of vector lattices with values in the completion of the Kantorovich space…

Functional Analysis · Mathematics 2018-12-31 B. N. Khabibullin , A. P. Rozit , E. B. Khabibullina

We investigate nef and movable cones of hypersurfaces in Mori dream spaces. The first result is: Let $Z$ be a smooth Mori dream space of dimension at least four whose extremal contractions are of fiber type of relative dimension at least…

Algebraic Geometry · Mathematics 2022-05-19 Long Wang

The classical Kneser-Milnor theorem says that every closed oriented connected 3-dimensional manifold admits a unique connected sum decomposition into manifolds that cannot be decomposed any further. We discuss to what degree such…

The cotangent bundle of a non-uniruled projective manifold is generically nef, due to a theorem of Miyaoka. We show that the cotangent bundle is actually generically ample, if the manifold is of general type and study in detail the case of…

Algebraic Geometry · Mathematics 2011-06-22 Thomas Peternell

To a generically big adelic divisor, we can associate an arithmetic Okounkov body, which is a pair of the geometric Okounkov body and the concave transform of the Green functions. In this paper, we show that the infimum of the concave…

Algebraic Geometry · Mathematics 2016-01-21 Hideaki Ikoma

Geometric conditions are given so that the leafwise reduced cohomology is of infinite dimension, specially for foliations with dense leaves on closed manifolds. The main new definition involved is the intersection number of subfoliations…

Geometric Topology · Mathematics 2013-11-15 Jesús A. Álvarez López , Gilbert Hector

We prove a bound relating the volume of a curve near a cusp in a hyperbolic manifold to its multiplicity at the cusp. The proof uses a hybrid technique employing both the geometry of the uniformizing group and the algebraic geometry of the…

Algebraic Geometry · Mathematics 2019-02-20 Benjamin Bakker , Jacob Tsimerman

We prove that a smooth well formed Fano weighted complete intersection of codimension 2 has a nef partition. We discuss applications of this fact to Mirror Symmetry. In particular we list all nef partitions for smooth well formed Fano…

Algebraic Geometry · Mathematics 2020-08-13 Victor Przyjalkowski , Constantin Shramov

C-cross topologies are introduced. Modifcations of the Kuratowski-Ulam Theorem are considered. Cardinal invariants add, cof, cov and non with respect to meager or nowhere dense subsets are compared. Remarks on invariants cof(nwdY) are…

General Topology · Mathematics 2007-05-23 Andrzej Kucharski , Szymon Plewik

Let $k$ be a finite field, a $p$-adic field or a number field. Let $K$ be a finite extension of the Laurent series field in $m$ variables $k((x_1,...,x_m))$ or, more generally, a finite extension of the field of rational functions…

Algebraic Geometry · Mathematics 2018-06-08 Diego Izquierdo

We determine the cones of effective and nef divisors on the toroidal compactification of the ball quotient model of the moduli space of complex cubic surfaces with a chosen line. From this we also compute the corresponding cones for the…

Algebraic Geometry · Mathematics 2025-03-26 Sebastian Casalaina-Martin , Samuel Grushevsky , Klaus Hulek

We show that any pseudo-effective divisor on a normal surface decomposes uniquely into its "integral positive" part and "integral negative" part, which is an integral analog of Zariski decompositions. By using this decomposition, we give…

Algebraic Geometry · Mathematics 2020-11-18 Makoto Enokizono

Campana introduced the class of special varieties as the varieties admitting no Bogomolov sheaves i.e. rank one coherent subsheaves of maximal Kodaira dimension in some exterior power of the cotangent bundle. Campana raised the question if…

Algebraic Geometry · Mathematics 2021-06-24 Jorge Vitorio Pereira , Erwan Rousseau , Frédéric Touzet

We show that the components, appearing in the decomposition theorem for contraction maps of torus actions of complexity one, are intersection cohomology complexes of even codimensional subvarieties. As a consequence, we obtain the vanishing…

Algebraic Geometry · Mathematics 2026-03-10 Marta Agustin Vicente , Narasimha Chary Bonala , Kevin Langlois

We prove that the Okounkov body of a big divisor with respect to a general flag on a smooth projective surface whose pseudo-effective cone is rational polyhedral decomposes as the Minkowski sum of finitely many simplices and line segments…

Algebraic Geometry · Mathematics 2016-08-11 Patrycja Łuszcz-Świdecka , David Schmitz

This article contains a new argument which proves vanishing of the first cohomology for negative vector bundles over a complex projective variety if the rank of the bundle is smaller than the dimension of the base. Similar argument is…

Algebraic Geometry · Mathematics 2007-05-23 Fedor Bogomolov

We prove a Bochner type vanishing theorem for compact complex manifolds $Y$ in Fujiki class $\mathcal C$, with vanishing first Chern class, that admit a cohomology class $[\alpha] \in H^{1,1}(Y,\mathbb R)$ which is numerically effective…

Differential Geometry · Mathematics 2019-01-10 Indranil Biswas , Sorin Dumitrescu , Henri Guenancia

We give an algebraic construction of the positive products of pseudo-effective classes first introduced by Boucksom, Demailly, Paun and Peternell, and use them to prove that the volume function on the Neron-Severi space of a projective…

Algebraic Geometry · Mathematics 2007-09-04 Sebastien Boucksom , Charles Favre , Mattias Jonsson