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We explain a correct proof of the decomposition theorem for direct images of constant Hodge modules by proper K\"ahler morphisms of complex manifolds. We also give some examples showing certain difficulty in the non-constant Hodge module…

Algebraic Geometry · Mathematics 2022-05-27 Morihiko Saito

It is shown that the normalized trace of Fedosov star product for quantum moment map depends only on the path component in the cohomology class of the symplectic form and the cohomology class of the closed formal 2-form required to define…

Symplectic Geometry · Mathematics 2021-02-24 Akito Futaki , Laurent La Fuente-Gravy

Let $M^n$ be a compact K$\ddot{a}$hler manifold with almost nonnegative Ricci curvature and nonzero first Betti number. We show that the holomorphic Euler number of $M^n$ vanishes, which gives a new obstruction for compact complex manifolds…

Differential Geometry · Mathematics 2022-08-02 Xiaoyang Chen

In this article we study cohomology of a group with coefficients in representations on Banach spaces and its stability under deformations. We show that small, metric deformations of the representation preserve vanishing of cohomology. As…

Group Theory · Mathematics 2014-09-03 Uri Bader , Piotr W. Nowak

By the work of Li, a compact co-K\"ahler manifold $M$ is a mapping torus $K_\varphi$, where $K$ is a K\"ahler manifold and $\varphi$ is a Hermitian isometry. We show here that there is always a finite cyclic cover $\bar M$ of the form $\bar…

Differential Geometry · Mathematics 2013-04-25 Giovanni Bazzoni , John Oprea

We show that compact K\"ahler manifolds have the rational cohomology ring of complex projective space provided a weighted sum of the lowest three eigenvalues of the K\"ahler curvature operator is positive. This follows from a more general…

Differential Geometry · Mathematics 2024-10-04 Peter Petersen , Matthias Wink

We prove that the one-loop deformation of any quaternionic K\"ahler manifold in the class of c-map spaces is locally inhomogeneous. As a corollary, we obtain that the full isometry group of the one-loop deformation of any homogeneous c-map…

Differential Geometry · Mathematics 2025-03-26 Vicente Cortés , Alejandro Gil-García , Arpan Saha

We apply the method of Dimca-Papadima to study the cohomology jump loci in the representation variety and the moduli space of vector bundles with vanishing chern classes for a compact K\"ahler manifold. We introduce modules over…

Algebraic Geometry · Mathematics 2013-03-28 Botong Wang

We show that any conformal vector field on a compact lcK manifold is Killing with respect to the Gauduchon metric. Furthermore, we prove that any conformal vector field on a compact lcK manifold whose K\"ahler cover is neither flat, nor…

Differential Geometry · Mathematics 2024-12-25 Andrei Moroianu , Mihaela Pilca

The existence of a vector field on a compact Kaehler manifold with nonempty zero locus and the properties of this zero locus strongly influence the geometry of the manifold. For example, J. Wahl proved that the existence of a vector field…

Algebraic Geometry · Mathematics 2007-05-23 Thomas Eckl

We study deformations of Lie groupoids by means of the cohomology which controls them. This cohomology turns out to provide an intrinsic model for the cohomology of a Lie groupoid with values in its adjoint representation. We prove several…

Differential Geometry · Mathematics 2020-11-19 Marius Crainic , João Nuno Mestre , Ivan Struchiner

We give a complex polarized variation of Hodge structure over a compact K"ahler manifold $M$ which controls all finite-dimensional complex polarized variations of Hodge structure over $M$ and their tensor relations. As a corollary, we…

Algebraic Geometry · Mathematics 2022-07-25 Hisashi Kasuya

We prove that the partial derivative of the volume function of big classes along any real divisor in a compact Kaehler manifold is equal to the numerical restricted volume of that class to the divisor. A consequence of our main result is…

Algebraic Geometry · Mathematics 2023-08-01 Duc-Viet Vu

In this article, we will explore the fundamental concepts, including various basic concepts on $d$-complex manifolds, along with several differential operators and examine the relationships between them. A $d$-K\"ahler manifold is a…

Differential Geometry · Mathematics 2024-06-17 Sanjay Amrutiya , Ayush Jaiswal

We prove that the only Bott manifolds such that the Futaki invariant vanishes for any K\"ahler class are isomorphic to the products of the projective lines.

Algebraic Geometry · Mathematics 2025-01-27 Hajime Ono , Yuji Sano , Naoto Yotsutani

We study the J-invariant and J-anti-invariant cohomological subgroups of the de Rham cohomology of a compact manifold M endowed with an almost-K\"ahler structure (J, \omega, g). In particular, almost-K\"ahler manifolds satisfying a…

Differential Geometry · Mathematics 2014-10-28 Daniele Angella , Adriano Tomassini , Weiyi Zhang

We show that complex symplectic structures need not be preserved under small deformations, and we find sufficient conditions for this to happen. We study various cohomologies of compact complex symplectic manifolds, obtaining some…

Differential Geometry · Mathematics 2025-07-08 Giovanni Bazzoni , Marco Freibert , Adela Latorre , Nicoletta Tardini

A locally conformally Kahler (LCK) manifold is a complex manifold admitting a Kahler covering, with the monodromy acting on this covering by homotheties. We define three cohomology invariants, the Lee class, the Morse-Novikov class, and the…

Differential Geometry · Mathematics 2015-05-13 Liviu Ornea , Misha Verbitsky

We give a simple geometric description of all formal deformation quantizations on a K\"ahler manifold $M$ which enjoy the following property of separation of variables into holomorphic and antiholomorphic ones. For each open subset…

High Energy Physics - Theory · Physics 2015-04-21 Karabegov Alexander

We study conformal Killing forms on compact 6-dimensional nearly K\"ahler manifolds. Our main result concerns forms of degree 3. Here we give a classification showing that all conformal Killing 3-forms are linear combinations of $d \omega$…

Differential Geometry · Mathematics 2019-03-19 Antonio M. Naveira , Uwe Semmelmann