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Related papers: Complex nilmanifolds and K\"ahler-like connections

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We show that a complex structure on a nilpotent almost abelian real Lie algebra is unique if it exists. As a consequence, we get full control over the cohomology and deformations of almost abelian complex nilmanifolds.

Differential Geometry · Mathematics 2025-02-06 Adrián Andrada , Romina M. Arroyo , María L. Barberis , Sönke Rollenske , Konstantin Wehler

We present some formulae related to the Chern-Ricci curvatures and scalar curvatures of special Hermitian metrics. We prove that a compact locally conformal K\"{a}hler manifold with constant nonpositive holomorphic sectional curvature is…

Differential Geometry · Mathematics 2019-05-09 Haojie Chen , Lingling Chen , Xiaolan Nie

Let $({X}, \omega)$ be a compact $n$-dimensional K\"ahler orbifold, the stabilizer groups of which are abelian and have rank at most two. Let ${E}$ be an orbi-ample vector bundle of rank $2$ over ${X}$ and let $H$ be a Hermitian metric on…

Differential Geometry · Mathematics 2026-05-26 Julius Ross , Shin Kim

A locally conformally K\"ahler (lcK) manifold is a complex manifold $(M,J)$ together with a Hermitian metric $g$ which is conformal to a K\"ahler metric in the neighbourhood of each point. In this paper we obtain three classification…

Differential Geometry · Mathematics 2021-06-15 Farid Madani , Andrei Moroianu , Mihaela Pilca

We give an account of old and new results concerning many types of non-K\"ahler metrics, with focus on the problem of their coexistence on compact complex manifolds, and their behaviour at deformations and blow-up. We also describe a…

Differential Geometry · Mathematics 2025-05-06 Liviu Ornea , Miron Stanciu

In this paper, left-invariant almost contact metric structures on three-dimensional non-unimodular Lie groups are investigated. It is proved that for every Riemannian Lie group, there is one of these structures. In addition, left-invariant…

Differential Geometry · Mathematics 2020-02-12 Pejhman Vatandoost-Miandehi , A. Razavi

Motivated by the recent work of Wu and Yau on the ampleness of canonical line bundle for compact K\"ahler manifolds with negative holomorphic sectional curvature, we introduce a new curvature notion called $\textbf{real bisectional…

Differential Geometry · Mathematics 2023-03-31 Xiaokui Yang , Fangyang Zheng

We consider unitary cocycle deformations of covariant $\ast$-differential calculi. We prove that complex structures, holomorphic bimodules and Chern connections on the deformed calculus are twists of their untwisted counterparts. Moreover,…

Quantum Algebra · Mathematics 2026-02-19 Jyotishman Bhowmick , Bappa Ghosh

In this work we deal with left invariant complex and symplectic structures on simply connected four dimensional solvable real Lie groups. We search the general form of such structures, when they exist and we make use of this information to…

Differential Geometry · Mathematics 2007-05-23 Gabriela Ovando

We give a simple interpretation of the adapted complex structure of Lempert-Szoke and Guillemin-Stenzel: it is given by a polar decomposition of the complexified manifold. We then give a twistorial construction of an SO(3)-invariant…

Differential Geometry · Mathematics 2007-05-23 Roger Bielawski

The almost complex Lie algebroids over smooth manifolds are introduced in the paper. In the first part we give some examples and we obtain a Newlander-Nirenberg type theorem on almost complex Lie algebroids. Next the almost Hermitian Lie…

Differential Geometry · Mathematics 2014-05-06 Cristian Ida , Paul Popescu

The covariant derivative of the K\"ahler form of an almost pseudo-Hermitian or of an almost para-Hermitian manifold satisfies certain algebraic relations. We show, conversely, that any 3-tensor which satisfies these algebraic relations can…

Differential Geometry · Mathematics 2010-12-23 Miguel Brozos-Vázquez , Eduardo García-Río , Peter Gilkey , Luis Hervella

We study bi-Lagrangian structures (a symplectic form with a pair of complementary Lagrangian foliations, also known as para-K\"ahler or K\"unneth structures) on nilmanifolds of dimension less than or equal to 6. In particular, building on…

Symplectic Geometry · Mathematics 2019-03-01 M. J. D. Hamilton

It is considered a differentiable manifold equipped with a pseudo-Riemannian metric and an almost contact 3-struc\-ture so that an almost contact metric structure and two almost contact B-metric structures are generated. There are…

Differential Geometry · Mathematics 2017-11-21 Mancho Manev

In this paper, we establish a "pseudo-effective" version of the holonomy principle for compact K\"{a}hler manifolds with nonnegative holomorphic sectional curvature. As applications, we prove that if a compact complex manifold $M$ admits a…

Differential Geometry · Mathematics 2024-08-07 Shiyu Zhang , Xi Zhang

In the present paper, we study compact complex manifolds admitting a Hermitian metric which is SKT and CYT and whose Bismut torsion is parallel. We first obtain a characterization of the universal cover of such manifolds as a product of a…

Differential Geometry · Mathematics 2024-11-20 Beatrice Brienza , Anna Fino , Gueo Grantcharov

The structure of nearly K\"ahler manifolds was studied by Gray in several papers. More recently, a relevant progress on the subject has been done by Nagy. Among other results, he proved that a strict and complete nearly K\"ahler manifold is…

Differential Geometry · Mathematics 2010-11-29 J. C. González Dávila , F. Martín Cabrera

We provide models that are as close as possible to being formal for a large class of compact manifolds that admit a transversely Kaehler structure, including Vaisman and quasi-Sasakian manifolds. As an application we are able to classify…

Differential Geometry · Mathematics 2022-03-18 Beniamino Cappelletti-Montano , Antonio De Nicola , Juan Carlos Marrero , Ivan Yudin

We prove that, for some classes of complex nilmanifolds, the Bott-Chern cohomology is completely determined by the Lie algebra associated to the nilmanifold with the induced complex structure. We use these tools to compute the Bott-Chern…

Differential Geometry · Mathematics 2013-08-20 Daniele Angella

We study HKT structures on nilpotent Lie groups and on associated nilmanifolds. We exhibit three weak HKT structures on $\R^8$ which are homogeneous with respect to extensions of Heisenberg type Lie groups. The corresponding hypercomplex…

Differential Geometry · Mathematics 2009-11-07 Isabel G. Dotti , Anna Fino