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We establish a relation between Lelong numbers and the full mass property of relative non-pluripolar products. We use it to show that if the restricted volume of a big cohomology class $\alpha$ in a compact K\"ahler $n$-dimensional manifold…

Complex Variables · Mathematics 2025-08-21 Duc-Bao Nguyen , Shuang Su , Duc-Viet Vu

We study a special type of almost complex structures, called pure and full and introduced by T.J. Li and W. Zhang, in relation to symplectic structures and Hard Lefschetz condition. We provide sufficient conditions to the existence of the…

Differential Geometry · Mathematics 2009-06-04 Anna Fino , Adriano Tomassini

Given a compact stratified pseudomanifold with a Thom-Mather stratification and a class of riemannian metrics over its regular part, we study the relationships between the $L^{2}$ de Rham and Hodge cohomology and the intersection cohomology…

Differential Geometry · Mathematics 2012-06-07 Francesco Bei

On Kahler 4-manifolds, not necessarily compact or of finite topological type, we obtain relationships between the fundamental group of compact embedded Levi-flat or pseudoconvex submanifold and the fundamental group of the ambient manifold…

Differential Geometry · Mathematics 2022-08-02 Brian Weber

We prove a general inequality for estimating the number of points of arbitrary complete intersections over a finite field. This extends a result of Deligne for nonsingular complete intersections. For normal complete intersections, this…

Algebraic Geometry · Mathematics 2009-09-15 Sudhir R. Ghorpade , Gilles Lachaud

We study a natural Hodge theoretic generalization of rational (or $\mathbb{Q}$-)homology manifolds through an invariant ${\rm HRH(Z)}$ where $Z$ is a complex algebraic variety. The defining property of this notion encodes the difference…

Algebraic Geometry · Mathematics 2025-01-27 Bradley Dirks , Sebastian Olano , Debaditya Raychaudhury

Given a polynomial endomorphism F of the n-dimensional affine space over a field K, we define a sequence of polynomial endomorphisms of the affine space associated to F. We call F nice if there exists an integer m such that the m-th term of…

Algebraic Geometry · Mathematics 2016-01-07 Elzbieta Adamus , Pawel Bogdan , Teresa Crespo , Zbigniew Hajto

In this paper we prove that the cohomology of smooth projective tropical varieties verify the tropical analogs of three fundamental theorems which govern the cohomology of complex projective varieties: Hard Lefschetz theorem, Hodge-Riemann…

Algebraic Geometry · Mathematics 2020-07-16 Omid Amini , Matthieu Piquerez

In two articles by Barthel, Brasselet, Fieseler and Kaup, and, Bressler and Lunts, a combinatorial theory of intersection cohomology and perverse sheaves has been developed on fans. In the first one, one tried to present everything on an…

Algebraic Geometry · Mathematics 2007-05-23 Karl-Heinz Fieseler

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

The goal of this survey is to present various results concerning the cohomology of pseudoeffective line bundles on compact K{\"a}hler manifolds, and related properties of their multiplier ideal sheaves. In case the curvature is strictly…

Complex Variables · Mathematics 2015-01-05 Jean-Pierre Demailly

Oeljeklaus-Toma (OT) manifolds are complex non-K\"ahler manifolds whose construction arises from specific number fields. In this note, we compute their de Rham cohomology in terms of invariants associated to the background number field.…

Differential Geometry · Mathematics 2018-10-01 Nicolina Istrati , Alexandra Otiman

We study the intersection form $F_X$ on the second cohomology group $H^2(X, \mathbb{Z})$ of a compact K\"ahler manifold $X$ of dimension $n$. Although the structure of $F_X$ is relatively well understood in dimensions two and three, much…

Algebraic Geometry · Mathematics 2025-11-11 Cinzia Bisi , Paolo Cascini , Luca Tasin

We complete the classification of order $5$ nonsymplectic automorphisms on hyper-K\"ahler fourfolds deformation equivalent to the Hilbert square of a K3 surface. We then compute the topological Lefschetz number of natural automorphisms of…

Algebraic Geometry · Mathematics 2020-01-16 Samuel Boissière , Marc Nieper-Wißkirchen , Kévin Tari

This paper is intended as the first step of a programme aiming to prove in the long run the long-conjectured closedness under holomorphic deformations of compact complex manifolds that are bimeromorphically equivalent to compact K\"ahler…

Differential Geometry · Mathematics 2018-02-07 Dan Popovici , Luis Ugarte

We make explicit computations in the formal symplectic geometry of Kontsevich and determine the Euler characteristics of the three cases, namely commutative, Lie and associative ones, up to certain weights.From these, we obtain some…

Algebraic Topology · Mathematics 2015-04-14 Shigeyuki Morita , Takuya Sakasai , Masaaki Suzuki

In this work, following the fundamental work of Boucksom we construct the nef cone of a compact complex manifold in higher codimension and give explicit examples where these cones are different. In the third section, we give two versions of…

Algebraic Geometry · Mathematics 2022-04-29 Xiaojun Wu

It is known that all complete intersection Artinian standard graded algebras of codimension 3 have the Weak Lefschetz Property. Unfortunately, this property does not continue to be true when you increase the number of minimal generators for…

Algebraic Geometry · Mathematics 2010-03-23 Alfio Ragusa , Giuseppe Zappala

We prove the Lefschetz duality for intersection (co)homology in the framework of $\partial$-pesudomanifolds. We work with general perversities and without restriction on the coefficient ring.

Algebraic Topology · Mathematics 2019-04-23 Martintxo Saralegi-Aranguren

In this paper we study the variability and rigidity of secondary characteristic classes which arise from flat connections on a manifold. Considering the connection as a Lie-algebra valued one-form, we study the characteristic map from Lie…

Differential Geometry · Mathematics 2007-05-23 Jerry Lodder