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Related papers: $L^2$ Fr\"olicher inequalities

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In this paper we discuss open problems concerning L^2-invariants focusing on approximation by towers of finite coverings.

Geometric Topology · Mathematics 2016-10-07 Wolfgang Lueck

We give four constructions of non-$\partial\bar\partial$ (hence non-K\"ahler) manifolds: (1) A simply connected page-$1$-$\partial\bar\partial$-manifold (2) A simply connected $dd^c+3$-manifold (3) For any $r\geq 2$, a simply connected…

Algebraic Geometry · Mathematics 2023-06-27 Hisashi Kasuya , Jonas Stelzig

In this work, we investigate compact K\"ahler manifolds with non-negative or quasi-positive mixed curvature coming from a linear combination of the Ricci and holomorphic sectional curvature, which covers various notions of curvature…

Differential Geometry · Mathematics 2024-08-27 Jianchun Chu , Man-Chun Lee , Jintian Zhu

Recently the so-called Atiyah conjecture about l^2-Betti numbers has been disproved. The counterexamples were found using a specific method of computing the spectral measure of a matrix over a complex group ring. We show that in many…

Geometric Topology · Mathematics 2016-08-10 Łukasz Grabowski , Thomas Schick

We consider a simple and natural coboundary operator, on the Lie algebra valued differential forms on a manifold, which in the abelian case reduces to usual exterior derivative of such forms. Using the corresponding de Rham cohomology Lie…

Geometric Topology · Mathematics 2007-05-23 Mukul Patel

We introduce the Hardy spaces for Fourier integral operators on Riemannian manifolds with bounded geometry. We then use these spaces to obtain improved local smoothing estimates for Fourier integral operators satisfying the cinematic…

Analysis of PDEs · Mathematics 2024-01-31 Naijia Liu , Jan Rozendaal , Liang Song , Lixin Yan

Compact hyperkaehler manifolds are higher-dimensional generalizations of K3 surfaces. The classical Global Torelli theorem for K3 surfaces, however, does not hold in higher dimensions. More precisely, a compact hyperkaehler manifold is in…

Algebraic Geometry · Mathematics 2013-09-12 Daniel Huybrechts

In this work, a refinement of the Cauchy--Schwarz inequality in inner product space is proved. A more general refinement of the Kato's inequality or the so called mixed Schwarz inequality is established. Refinements of some famous numerical…

Functional Analysis · Mathematics 2020-09-07 Mohammad W. Alomari

We define the notion of L^2 homology and L^2 Betti numbers for a tracial von Neumann algebra, or, more generally, for any involutive algebra with a trace. The definition of these invariants is obtained from the definition of L^2 homology…

Operator Algebras · Mathematics 2007-05-23 Alain Connes , Dimitri Shlyakhtenko

We develop the theory of twisted L^2-cohomology and twisted spectral invariants for flat Hilbertian bundles over compact manifolds. They can be viewed as functions on the first de Rham cohomology of M and they generalize the standard…

dg-ga · Mathematics 2008-02-03 Varghese Mathai , Mikhail Shubin

We provide further techniques to study the Dolbeault and Bott-Chern cohomologies of deformations of solvmanifolds by means of finite-dimensional complexes. By these techniques, we can compute the Dolbeault and Bott-Chern cohomologies of…

Complex Variables · Mathematics 2017-05-15 Daniele Angella , Hisashi Kasuya

We establish sharp remainder terms of the $L^{2}$-Caffarelli-Kohn-Niren\-berg inequalities on homogeneous groups, yielding the inequalities with best constants. Our methods also give new sharp Caffarelli-Kohn-Nirenberg type inequalities in…

Functional Analysis · Mathematics 2016-11-16 Michael Ruzhansky , Durvudkhan Suragan

Given a complete K\"ahler manifold $(X,\,\omega)$ with finite second Betti number, a smooth complex hypersurface $Y\subset X$ and a smooth real $d$-closed $(1,\,1)$-form $\alpha$ on $X$ with arbitrary, possibly non-rational, De Rham…

Complex Variables · Mathematics 2023-09-21 Dan Popovici

This article is concerned with Chern class and Chern number inequalities on polarized manifolds and nef vector bundles. For a polarized pair $(M,L)$ with $L$ very ample, our first main result is a family of sharp Chern class inequalities.…

Differential Geometry · Mathematics 2022-05-11 Ping Li , Fangyang Zheng

When studying the weighted Hardy-Rellich inequality in $L^2$ with the full gradient replaced by the radial derivative the best constant becomes trivially larger or equal than in the first situation. Our contribution is to determine the new…

Analysis of PDEs · Mathematics 2024-06-25 Cristian Cazacu , Irina Fidel

For any irreducible compact homogeneous K\"ahler manifold, we classify the compact tight Lagrangian submanifolds which have the Z_2-homology of a sphere.

Differential Geometry · Mathematics 2014-02-12 Claudio Gorodski , Fabio Podestà

We study Poincar\'e type $L^p$ inequality on a compact semialgebraic subset of $\R^n$ for $p>>1$. First we derive a local inequality by using a Lipschitz deformation retraction with estimates on its derivatives. Then, we extend the local…

Geometric Topology · Mathematics 2011-07-04 Leonid Shartser

Motivated by understanding the limiting case of a certain systolic inequality we study compact Riemannian manifolds having all harmonic 1-forms of constant length. We give complete characterizations as far as K\"ahler and hyperbolic…

Differential Geometry · Mathematics 2008-10-10 Paul-Andi Nagy

Looijenga--Lunts and Verbitsky showed that the cohomology of a compact hyper-K\"ahler manifold $X$ admits a natural action by the Lie algebra $\mathfrak{so} (4, b_2(X)-2)$, generalizing the Hard Lefschetz decomposition for compact K\"ahler…

Algebraic Geometry · Mathematics 2024-04-25 Mark Green , Yoon-Joo Kim , Radu Laza , Colleen Robles

We consider interpolation inequalities for imbeddings of the $l^2$-sequence spaces over $d$-dimensional lattices into the $l^\infty_0$ spaces written as interpolation inequality between the $l^2$-norm of a sequence and its difference. A…

Analysis of PDEs · Mathematics 2014-07-03 Alexei Ilyin , Ari Laptev , Sergey Zelik