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Related papers: Intersection theory of nef b-divisor classes

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We describe the dimensional reduction of the IIB B-fields in F-theory using a conjectured description of normalizable B-fields in terms of perverse sheaves. Computations are facilitated using the Decomposition Theorem. Many of our…

Algebraic Geometry · Mathematics 2022-04-29 Sheldon Katz , Washington Taylor

Let X be a very general complete intersection in complex projective space and we denote by $F_r(X)$ the variety of r-planes in X, for $r\geq 1$. We show that the Picard number of $F_r(X)$ is 1, as soon as $\dim F_r(X)\geq 2$, except when X…

Algebraic Geometry · Mathematics 2010-10-26 Zhi Jiang

We show a weak form of the function field version of Oesterle's abc conjecture. It asserts that, if $B$ is a complex projective connected curve, the number of intersection points, counted without multiplicities, of a fixed divisor $D$ of…

Number Theory · Mathematics 2007-05-23 Frederic Campana

The dimension of any module over an algebra of affiliated operators ${\mathcal U}$ of a finite von Neumann algebra ${\mathcal A}$ is defined using a trace on ${\mathcal A}.$ All zero-dimensional ${\mathcal U}$-modules constitute the torsion…

Rings and Algebras · Mathematics 2010-09-14 Lia Vas

The Hurwitz form of a projective variety characterizes linear spaces of complementary dimension which meet the variety non-transversally. We extend this notion to varieties in a product of projective spaces. This parallels the multigraded…

Algebraic Geometry · Mathematics 2026-02-24 Elizabeth Pratt , Luca Sodomaco , Bernd Sturmfels

In this paper, we establish the following family version of Habegger's bounded height theorem on abelian varieties: a locally closed subvariety of an abelian scheme with Gao's $t^{\mathrm{th}}$ degeneracy locus removed, intersected with all…

Number Theory · Mathematics 2024-11-26 Tangli Ge

We solve three open problems concerning infinite-dimensional Lie groups posed in a recent survey article by K.-H. Neeb: (1) There exists a subgroup of some infinite-dimensional Lie group G which does not admit an initial Lie subgroup…

Group Theory · Mathematics 2008-01-15 Helge Glockner

As an application of P. Delgine's theorem (Esnault and Kerz in Acta Math. Vietnam. 37:531-562, 2012) on a finiteness of $l$-adic sheaves on a variety over a finite field, we show the finiteness of \'etale coverings of such a variety with…

Number Theory · Mathematics 2016-12-12 Toshiro Hiranouchi

We prove that the $p^\infty$-torsion of the transcendental Brauer group of an abelian variety over a finitely generated field of characteristic $p>0$ is bounded. This answers a (variant of a) question asked by Skorobogatov and Zarhin for…

Algebraic Geometry · Mathematics 2025-04-14 Marco D'Addezio

We prove that Schur classes of nef vector bundles are limits of classes that have a property analogous to the Hodge-Riemann bilinear relations. We give a number of applications, including (1) new log-concavity statements about…

Algebraic Geometry · Mathematics 2021-06-22 Julius Ross , Matei Toma

These are the lecture notes based on earlier papers with some additional new results. New and simple proofs are given for local freeness theorem and the semipositivity theorem. A decomposition theorem for higher direct images of dualizing…

Algebraic Geometry · Mathematics 2013-10-15 Yujiro Kawamata

In continuation of the paper [3], we discuss various consequences of Hahn-Banach theorem for bounded b-linear functional in linear n-normed space and describe the notion of reflexivity of linear n-normed space with respect to bounded…

Functional Analysis · Mathematics 2024-10-29 Prasenjit Ghosh , Tapas Kumar Samanta

This paper has two aims. The former is to give an introduction to our earlier work on the Hodge theory of algebraic maps and more generally to some of the main themes of the theory of perverse sheaves and to some of its geometric…

Algebraic Geometry · Mathematics 2007-05-23 Mark Andrea A. de Cataldo , Luca Migliorini

We study the quotient of the mapping class group $\operatorname{Mod}_g^n$ of a surface of genus $g$ with $n$ punctures, by the subgroup $\operatorname{Mod}_g^n[p]$ generated by the $p$-th powers of Dehn twists. Our first main result is that…

Geometric Topology · Mathematics 2024-07-22 Javier Aramayona , Louis Funar

We prove lower bounds for the minimum distance of algebraic geometry codes over surfaces whose canonical divisor is either nef or anti-strictly nef and over surfaces without irreducible curves of small genus. We sharpen these lower bounds…

Algebraic Geometry · Mathematics 2020-03-04 Yves Aubry , Elena Berardini , Fabien Herbaut , Marc Perret

I consider the class of surfaces $X$ over algebraically closed fields with numerical invariants given in the title. In characteristic zero, this class contains fake projective planes which were introduced by David Mumford. I prove that in…

Algebraic Geometry · Mathematics 2025-08-19 Kirti Joshi

We study intersection theory on the relative Hilbert scheme of a family of nodal-or-smooth curves, over a base of arbitrary dimension. We introduce an additive group called 'discriminant module', generated by diagonal loci, node scrolls,…

Algebraic Geometry · Mathematics 2013-10-24 Ziv Ran

We give lower bounds for the degree of the discriminant with respect to y of separable polynomials f in K[x,y] over an algebraically closed field of characteristic zero. Depending on the invariants involved in the lower bound, we give a…

Algebraic Geometry · Mathematics 2015-07-07 Denis Simon , Martin Weimann

Questions related to Brauer-Manin obstructions to the Hasse principle and weak approximation for homogeneous spaces of tori over a number field are well-studied, generally using arithmetic duality theorems, starting with works of Sansuc and…

Number Theory · Mathematics 2025-10-06 Azur Đonlagić

We describe algorithms for computing the intersection numbers of divisors and of Chern classes of the Hodge bundle on the moduli spaces of stable pointed curves. We also discuss the implementations and the results obtained. There are…

alg-geom · Mathematics 2008-02-03 Carel Faber