English
Related papers

Related papers: Reduction of Vaisman structures in complex and qua…

200 papers

We prove that a compact lcK manifold with holomorphic Lee vector field is Vaisman provided that either the Lee field has constant norm or the metric is Gauduchon (i.e., the Lee field is divergence-free). We also give examples of compact lcK…

Differential Geometry · Mathematics 2019-01-08 Andrei Moroianu , Sergiu Moroianu , Liviu Ornea

Let M be a compact locally conformal hyperkaehler manifold. We prove a version of Kodaira-Nakano vanishing theorem for M. This is used to show that M admits no holomorphic differential forms, and the cohomology of the structure sheaf…

Differential Geometry · Mathematics 2007-05-23 Misha Verbitsky

We classify and investigate locally conformally K\"ahler structures on four-dimensional solvable Lie algebras up to linear equivalence. As an application we can produce many examples in higher dimension, here including lcK structures on…

Differential Geometry · Mathematics 2019-12-23 Daniele Angella , Marcos Origlia

We give an explicit local classification of conformally equivalent but oppositely oriented Kaehler metrics on a 4-manifold which are toric with respect to a common 2-torus action. In the generic case, these structures have an intriguing…

Differential Geometry · Mathematics 2013-03-01 Vestislav Apostolov , David M. J. Calderbank , Paul Gauduchon

It is well known that the curvature tensor of a pseudo-Riemannian manifold can be decomposed with respect to the pseudo-orthogonal group into the sum of the Weyl conformal curvature tensor, the traceless part of the Ricci tensor and of the…

Differential Geometry · Mathematics 2018-08-21 Anton S. Galaev

We construct symplectic and K\"ahler ray reduced spaces and discuss their relation with the Marsden-Weinstein (point) reduction. This K\"ahler reduction is well defined even when the momentum value is not totally isotropic. The…

Differential Geometry · Mathematics 2008-03-18 Oana Mihaela Drăgulete

A Cartan manifold is a smooth manifold M whose slit cotangent bundle T*M0 is endowed with a regular Hamiltonian K which is positively homogeneous of degree 2 in momenta. The Hamiltonian K defines a (pseudo)-Riemannian metric gij in the…

Mathematical Physics · Physics 2012-10-20 E. Peyghan , A. Tayebi , A. Ahmadi

We study compact toric strict locally conformally K\"ahler manifolds. We show that the Kodaira dimension of the underlying complex manifold is $-\infty$ and that the only compact complex surfaces admitting toric strict locally conformally…

Differential Geometry · Mathematics 2019-01-08 Farid Madani , Andrei Moroianu , Mihaela Pilca

We study a system of equations on a compact complex manifold, that couples the scalar curvature of a Kaehler metric with a spectral function of a first-order deformation of the complex structure. The system comes from an…

Differential Geometry · Mathematics 2022-07-08 Carlo Scarpa

As proven in a celebrated theorem due to Vaisman, pure locally conformally K\"ahler metrics do not exist on compact K\"ahler manifolds. In a previous paper, we extended this result to the singular setting, more precisely to K\"ahler spaces…

Differential Geometry · Mathematics 2024-05-08 Ovidiu Preda , Miron Stanciu

We obtain a class of locally symetric Kaehler Einstein structures on the nonzero cotangent bundle of a Riemannian manifold of positive constant sectional curvature. The obtained class of Kaehler Einstein structures depends on one essential…

Differential Geometry · Mathematics 2007-05-23 D. D. Porosniuc

Let M be a hypercomplex Hermitian manifold, (M,I) the same manifold considered as a complex Hermitian with a complex structure I induced by the quaternions. The standard linear-algebraic construction produces a canonical nowhere degenerate…

Algebraic Geometry · Mathematics 2007-05-23 Misha Verbitsky

This article reveals a significant connection in geometry: when the Lee form $\theta$ is normal to an almost Hermitian manifold $N$, it implies that $N$ possesses a nearly K\"ahler structure. Investigating locally conformally Spin(7)…

Differential Geometry · Mathematics 2024-03-04 Eyup Yalcinkaya

In the first part of this note we study compact Riemannian manifolds (M,g) whose Riemannian product with R is conformally Einstein. We then consider compact 6--dimensional almost Hermitian manifolds of type W_1+W_4 in the Gray--Hervella…

Differential Geometry · Mathematics 2019-01-08 Andrei Moroianu , Liviu Ornea

In this paper, we study the existence of various harmonic maps from Hermitian manifolds to Kaehler, Hermitian and Riemannian manifolds respectively. By using refined Bochner formulas on Hermitian (possibly non-Kaehler) manifolds, we derive…

Differential Geometry · Mathematics 2014-03-27 Kefeng Liu , Xiaokui Yang

In this paper, we first define the complexification of a real analytic map between real analytic Koszul manifolds and show that the complexified map is the holomorphic extension of the original map. Next we define an anti-Kaehler metric…

Differential Geometry · Mathematics 2015-08-07 Naoyuki Koike

For compact K\"ahlerian manifolds, the holomorphic pseudosymmetry reduces to the local symmetry if additionally the scalar curvature is constant and the structure function is non-negative. Similarly, the holomorphic Ricci-pseudosymmetry…

Differential Geometry · Mathematics 2010-11-18 Zbigniew Olszak

The notions of coK\"{a}hler manifolds and 3-cosymplectic manifolds are odd-dimensional analogues of the ones of K\"{a}hler manifolds and hyperK\"{a}hler manifolds, respectively. In this paper, we obtain reduction theorems of coK\"{a}hler…

Symplectic Geometry · Mathematics 2024-10-15 Shuhei Yonehara

We present a new method for classifying naturally reductive homogeneous spaces -- i.\,e.~homogeneous Riemannian manifolds admitting a metric connection with skew torsion that has parallel torsion \emph{and} curvature. This method is based…

Differential Geometry · Mathematics 2014-12-02 Ilka Agricola , Ana Cristina Ferreira , Thomas Friedrich

We extend harmonic map techniques to the setting of more general differential equations in conformal geometry. We obtain an extension of Siu's rigidity to Kahler-Weyl geometry and apply the latter to Vaisman's conjecture. Other applications…

Differential Geometry · Mathematics 2014-02-26 Gerasim Kokarev