English
Related papers

Related papers: On astheno-Kaehler metrics

200 papers

We investigate harmonic forms of geometrically formal metrics, which are defined as those having the exterior product of any two harmonic forms still harmonic. We prove that a formal Sasakian metric can exist only on a real cohomology…

Differential Geometry · Mathematics 2014-02-26 Jean-Francois Grosjean , Paul-Andi Nagy

We derive some necessary conditions on a Riemannian metric $(M, g)$ in four dimensions for it to be locally conformal to K\"ahler. If the conformal curvature is non anti--self--dual, the self--dual Weyl spinor must be of algebraic type $D$…

Differential Geometry · Mathematics 2015-05-13 Maciej Dunajski , Paul Tod

We give an explicit formula for the quaternionic K\"ahler metrics obtained by the HK/QK correspondence. As an application, we give a new proof of the fact that the Ferrara-Sabharwal metric as well as its one-loop deformation is quaternionic…

Differential Geometry · Mathematics 2015-03-31 Dmitri V. Alekseevsky , Vicente Cortés , Malte Dyckmanns , Thomas Mohaupt

We examine the class of compact Hermitian manifolds with constant holomorphic sectional curvature. Such manifolds are conjectured to be K\"ahler (hence a complex space form) when the constant is non-zero and Chern flat (hence a quotient of…

Differential Geometry · Mathematics 2022-10-18 Wu Zhou , Fangyang Zheng

Let $(M,I)$ be an almost complex 6-manifold. The obstruction to integrability of almost complex structure (so-called Nijenhuis tensor) maps a 3-dimensional bundle to a 3-dimensional one. We say that Nijenhuis tensor is non-degenerate if it…

Differential Geometry · Mathematics 2008-04-13 Misha Verbitsky

Our recent work about fully non-linear elliptic equations on compact manifolds with a flat hyperk\"ahler metric is hereby extended to the parabolic setting. This approach will help us to study some problems arising from hyperhermitian…

Differential Geometry · Mathematics 2023-06-02 Giovanni Gentili , Jiaogen Zhang

We study the construction and classification of weakly Bochner-flat (WBF) metrics (i.e., Kahler metrics with coclosed Bochner tensor) on compact complex manifolds. A Kahler metric is WBF if and only if its `normalized' Ricci form is a…

Differential Geometry · Mathematics 2008-07-21 Vestislav Apostolov , David M. J. Calderbank , Paul Gauduchon , Christina W. Tonnesen-Friedman

In this paper we study the geometry of the total space $Y$ of a cotangent bundle to a K\"ahler manifold $N$ where $N$ is obtained as a K\"ahler reduction from $\mathbb C^n$. Using the hyperk\"ahler reduction we construct a hyperk\"ahler…

Differential Geometry · Mathematics 2021-05-25 Anna Abasheva

We consider a complex Hermitian manifold of complex dimensions four with a Hermitian metric and a Chern connection. It is shown that the action that determines the dynamics of the metric is unique, provided that the linearized Einstein…

High Energy Physics - Theory · Physics 2009-11-11 Ali H. Chamseddine

Almost hypercomplex pseudo-Hermitian manifolds are considered. Isotropic hyper-K\"ahler manifolds are introduced. A 4-parametric family of 4-dimensional manifolds of this type is constructed on a Lie group. This family is characterized…

Differential Geometry · Mathematics 2012-05-09 Kostadin Gribachev , Mancho Manev

We revisit Brunella's proof of the fact that Kato surfaces admit locally conformally K\" ahler metrics, and we show that it holds for a large class of higher dimensional complex manifolds containing a global spherical shell. On the other…

Algebraic Geometry · Mathematics 2019-06-27 Nicolina Istrati , Alexandra Otiman , Massimiliano Pontecorvo

The geometry arising from Michelson & Strominger's study of N=4B supersymmetric quantum mechanics with superconformal D(2,1;alpha)-symmetry is a hyperKaehler manifold with torsion (HKT) together with a special homothety. It is shown that…

Differential Geometry · Mathematics 2009-11-07 Yat Sun Poon , Andrew Swann

We study equivalence of invariant metrics on noncompact K\"ahler manifolds with a complete Bergman metric of bounded curvature. Especially only the boundedness of the ratio between Bergman kernel and the $n$-times wedge product of Bergman…

Differential Geometry · Mathematics 2023-12-04 Gunhee Cho , Kyu-Hwan Lee

We investigate the conditions under which astheno-K\"ahler structures can be identified on the product of two compact trans-Sasakian manifolds of dimensions greater than 2.

Differential Geometry · Mathematics 2025-07-02 Punam Gupta , Nidhi Yadav

In this paper, we construct metallic K\"ahler and nearly metallic K\"ahler structures on Riemanian manifolds. For such manifolds with these structures, we study curvature properties. Also we describe linear connections on the manifold,…

General Mathematics · Mathematics 2019-07-02 Sibel Turanli , Aydin Gezer , Hasan Cakicioglu

Let $M_1$ and $M_2$ be two K\"ahler manifolds. We call $M_1$ and $M_2$ {\em relatives} if they share a non-trivial K\"ahler submanifold $S$, namely, if there exist two holomorphic and isometric immersions (K\"ahler immersions) $h_1: S\to…

Differential Geometry · Mathematics 2007-05-23 Antonio J. Di Scala , Andrea Loi

K\"ahler-Einstein metrics for polarized families of Calabi-Yau manifolds define a natural hermitian metric on the relative canonical bundle. The fact that the curvature form is equal to the pull-back of the Weil-Petersson form up to a…

Complex Variables · Mathematics 2019-01-23 Matthias Braun , Young-Jun Choi , Georg Schumacher

A $p$-K\"ahler structure on a complex manifold of complex dimension $n$ is given by a $d$-closed transverse real $(p,p)$-form. In the paper we study the existence of $p$-K\"ahler structures on compact quotients of simply connected Lie…

Differential Geometry · Mathematics 2024-04-04 Anna Fino , Asia Mainenti

Let L be an ample holomorphic line bundle over a compact complex Hermitian manifold X. Any fixed smooth Hermitian metric on L induces a Hilbert space structure on the space of global holomorphic sections with values in the k:th tensor power…

Complex Variables · Mathematics 2007-05-23 Robert Berman

A long-standing conjecture in non-K\"ahler geometry states that if the Chern (or Levi-Civita) holomorphic sectional curvature of a compact Hermitian manifold is a constant $c$, then the metric must be K\"ahler when $c\neq 0$ and must be…

Differential Geometry · Mathematics 2026-03-17 Yulu Li , Fangyang Zheng