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Related papers: Locally conformal Kaehler reduction

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We investigate a class of locally conformal almost K\"ahler structures and prove that, under some conditions, this class is a subclass of almost K\"ahler structures. We show that a locally conformal almost K\"ahler manifold admits a…

General Mathematics · Mathematics 2021-04-02 Ntokozo Sibonelo Khuzwayo , Fortuné Massamba

A compact complex manifold $V$ is called Vaisman if it admits an Hermitian metric which is conformal to a K\"ahler one, and a non-isometric conformal action by $\mathbb C$. It is called quasi-regular if the $\mathbb C$-action has closed…

Differential Geometry · Mathematics 2024-05-24 Liviu Ornea , Misha Verbitsky

In this paper we examine different aspects of the geometry of closed conformal vector fields on Riemannian manifolds. We begin by getting obstructions to the existence of closed conformal and nonparallel vector fields on complete manifolds…

Differential Geometry · Mathematics 2010-04-01 A. Caminha

We describe some L-infinity model for the local period map of a compact Kaehler manifold. Applications include the study of deformations with associated variation of Hodge structure constrained by certain closed strata of the Grassmannian…

Algebraic Geometry · Mathematics 2018-11-06 Ruggero Bandiera , Marco Manetti

A complex Hermitian $n$-manifold $(M,I, \omega)$ is called locally conformally Kahler (LCK) if $d\omega=\theta\wedge\omega$, where $\theta$ is a closed 1-form, balanced if $\omega^{n-1}$ is closed, and SKT if $dId\omega=0$. We conjecture…

Differential Geometry · Mathematics 2025-09-18 Liviu Ornea , Misha Verbitsky

We report on a few interrelations between bi-Hermitian metrics and locally conformally K\"ahler metrics on complex surfaces.

Differential Geometry · Mathematics 2025-01-13 Massimiliano Pontecorvo

We review the general properties of target spaces of hypermultiplets, which are quaternionic-like manifolds, and discuss the relations between these manifolds and their symmetry generators. We explicitly construct a one-to-one map between…

High Energy Physics - Theory · Physics 2009-11-10 Eric Bergshoeff , Sorin Cucu , Tim de Wit , Jos Gheerardyn , Stefan Vandoren , Antoine Van Proeyen

The Bochner tensor is the K\"ahler analogue of the conformal Weyl tensor. In this article, we derive local (i.e., in a neighbourhood of almost every point) normal forms for a (pseudo-)K\"ahler manifold with vanishing Bochner tensor. The…

Differential Geometry · Mathematics 2017-09-27 Alexey V. Bolsinov , Stefan Rosemann

Ambrose and Singer characterized connected, simply-connected and complete homogeneous Riemannian manifolds as Riemannian manifolds admitting a metric connection such that its curvature and torsion are parallel. The aim of this paper is to…

Differential Geometry · Mathematics 2014-05-06 Ignacio Luján

A locally conformally K\"ahler (LCK) manifold is a complex manifold $M$ which has a K\"ahler structure on its cover, such that the deck transform group acts on it by homotheties. Assume that the K\"ahler form is exact on the minimal…

Differential Geometry · Mathematics 2024-05-24 Liviu Ornea , Misha Verbitsky

We show that if a connected compact k\"ahlerian surface $M$ with nonpositive gaussian curvature is furnished with a closed conformal vector field $\xi$ whose singular points are isolated, then $M$ is isometric to a flat torus and $\xi$ is…

Differential Geometry · Mathematics 2017-05-31 Antonio Caminha

Given a compact constant scalar curvature Kaehler orbifold, with nontrivial holomorphic vector fields, whose singularities admit a local ALE Kaehler Ricci-flat resolution, we find sufficient conditions on the position of the singular points…

Differential Geometry · Mathematics 2015-07-21 Claudio Arezzo , Riccardo Lena , Lorenzo Mazzieri

We use a new method to give conditions for the existence of a local isometric immersion of a Riemannian $n$-manifold $M$ in $\mathbb{R}^{n+k}$, for a given $n$ and $k$. These equate to the (local) existence of a $k$-tuple of scalar fields…

Differential Geometry · Mathematics 2019-09-02 Dan Gregorian Fodor

We study the basic geometric properties of an indefinite locally conformal Kaehler manifold.

Differential Geometry · Mathematics 2007-05-23 Sorin Dragomir , Krishan L. Duggal

An LCK (locally conformally Kahler) manifold is a complex manifold admitting a Kahler covering with monodromy acting by homotheties. Hopf manifolds and their submanifolds are the prime examples. This book presents an introduction to the…

Differential Geometry · Mathematics 2024-12-10 Liviu Ornea , Misha Verbitsky

We investigate special lcs and twisted Hamiltonian torus actions on strict lcs manifolds and characterize them geometrically in terms of the minimal presentation. We prove a convexity theorem for the corresponding twisted moment map,…

Differential Geometry · Mathematics 2018-12-05 Florin Belgun , Oliver Goertsches , David Petrecca

We give a classification for connected complete locally irreducible Riemannian manifolds with nonpositive curvature operator, which admit a nonzero closed or co-closed conformal Killing $L^{2}-$form. Moreover, we prove vanishing theorems…

Differential Geometry · Mathematics 2017-03-29 Sergey Stepanov , Irina Tsyganok

An LCK (locally conformally Kahler) manifold is a complex manifold $(M,I)$ equipped with a Hermitian form $\omega$ and a closed 1-form $\theta$, called the Lee form, such that $d\omega=\theta\wedge\omega$. An LCK manifold with potential is…

Differential Geometry · Mathematics 2025-01-13 Liviu Ornea , Misha Verbitsky

We prove a structure theorem for compact aspherical Lorentz manifolds with abundant local symmetry. If M is a compact, aspherical, real-analytic, complete Lorentz manifold such that the isometry group of the universal cover has semisimple…

Differential Geometry · Mathematics 2007-05-23 Karin Melnick

Let U be a real form of a complex semisimple Lie group, and tau, sigma, a pair of commuting involutions on U. This data corresponds to a reflective submanifold of a symmetric space, U/K. We define an associated integrable system, and…

Differential Geometry · Mathematics 2007-10-06 David Brander