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

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We give a characterization of almost abelian Lie groups carrying left invariant hypercomplex structures and we show that the corresponding Obata connection is always flat. We determine when such Lie groups admit HKT metrics and study the…

Differential Geometry · Mathematics 2023-04-26 Adrián Andrada , María Laura Barberis

We give a partial account of some problems concerning cohomological invariants and metric properties of complex non-K\"ahler manifolds.

Differential Geometry · Mathematics 2026-02-04 Daniele Angella , Nicoletta Tardini

On a Hermitian manifold, the Chern connection can induce a metric connection on the background Riemannian manifold. We call the sectional curvature of the metric connection induced by the Chern connection the Chern sectional curvature of…

Differential Geometry · Mathematics 2024-03-20 Pandeng Cao , Hongjun Li

On a complex manifold an Hermitian metric which is simultaneously SKT and balanced has to be necessarily K\"ahler. It has been conjectured that if a compact complex manifold (M,J) has an SKT metric and a balanced metric both compatible with…

Differential Geometry · Mathematics 2015-06-18 Anna Fino , Luigi Vezzoni

We consider an almost complex manifold with Norden metric (i. e. a metric with respect to which the almost complex structure is an anti-isometry). On such a manifold we study a linear connection preserving the almost complex structure and…

Differential Geometry · Mathematics 2011-01-24 Dimitar Mekerov

In a paper by Angella, Otal, Ugarte, and Villacampa, the authors conjectured that on a compact Hermitian manifold, if a Gauduchon connection other than Chern or Strominger is K\"ahler-like, then the Hermitian metric must be K\"ahler. They…

Differential Geometry · Mathematics 2023-02-24 Quanting Zhao , Fangyang Zheng

Connections with (skew-symmetric) torsion on non-symmetric Riemannian manifold satisfying the Einstein metricity condition (NGT with torsion) are considered. It is shown that an almost Hermitian manifold is an NGT with torsion if and only…

Differential Geometry · Mathematics 2016-03-23 Stefan Ivanov , Milan Zlatanovic

An old open question in non-K\"ahler geometry predicts that any compact Hermitian manifold with constant holomorphic sectional curvature must be K\"ahler or Chern flat. The conjecture is known to be true in dimension $2$ due to the work by…

Differential Geometry · Mathematics 2025-06-19 Xin Huang , Fangyang Zheng

In this article, we examine the behavior of the Riemannian and Hermitian curvature tensors of a Hermitian metric, when one of the curvature tensors obeys all the symmetry conditions of the curvature tensor of a K\"ahler metric. We will call…

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

We complete the classification of compact Hermitian manifolds admitting a flat Gauduchon connection. In particular, we establish a conjecture of Yang and Zheng, showing that apart from the cases of a flat Chern or Bismut connection, such…

Differential Geometry · Mathematics 2022-07-20 Ramiro A. Lafuente , James Stanfield

We use Bott-Chern cohomology to measure the non-K\"ahlerianity of 6-dimensional nilmanifolds endowed with the invariant complex structures in M. Ceballos, A. Otal, L. Ugarte, and R. Villacampa's classification, [Invariant Complex Structures…

Differential Geometry · Mathematics 2015-08-11 Daniele Angella , Maria Giovanna Franzini , Federico Alberto Rossi

We study Lie algebras endowed with an abelian complex structure which admit a symplectic form compatible with the complex structure. We prove that each of those Lie algebras is completely determined by a pair (U,H) where U is a complex…

Differential Geometry · Mathematics 2015-06-05 Ignacio Bajo , Esperanza Sanmartín

We study the structure of Lie groups admitting left invariant abelian complex structures in terms of commutative associative algebras. If, in addition, the Lie group is equipped with a left invariant Hermitian structure, it turns out that…

Differential Geometry · Mathematics 2011-07-01 Adrian Andrada , Maria Laura Barberis , Isabel Dotti

The subject of investigations are the almost hypercomplex manifolds with Hermitian and anti-Hermitian (Norden) metrics. A linear connection D is introduced such that the structure of these manifolds is parallel with respect to D and its…

Differential Geometry · Mathematics 2012-05-08 Mancho Manev , Kostadin Gribachev

We introduce the notion of even Clifford structures on Riemannian manifolds, a framework generalizing almost Hermitian and quaternion-Hermitian geometries. We give the complete classification of manifolds carrying parallel even Clifford…

Differential Geometry · Mathematics 2019-01-08 Andrei Moroianu , Uwe Semmelmann

We classify nilpotent Lie algebras with complex structures of weakly non-nilpotent type in real dimension eight, which is the lowest dimension where they arise. Our study, together with previous results on strongly non-nilpotent structures,…

Differential Geometry · Mathematics 2025-02-10 A. Latorre , L. Ugarte

A local classification of the Hermitian manifolds with flat associated connection is given. Hermitian manifolds admitting locally a conformal metric with flat associated connection are characterized by a curvature identity. Locally…

Differential Geometry · Mathematics 2011-09-15 Georgi Ganchev , Ognian Kassabov

In this article, we study Hermitian manifolds whose Bismut-Strominger connection has parallel torsion tensor, which will be called {\em Bismut torsion parallel manifolds,} or {\em BTP} manifolds for short. We obtain a necessary and…

Differential Geometry · Mathematics 2022-10-18 Quanting Zhao , Fangyang Zheng

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

An old conjecture in non-K\"ahler geometry states that, if a compact Hermitian manifold has constant holomorphic sectional curvature, then the metric must be K\"ahler (when the constant is non-zero) or Chern flat (when the constant is…

Differential Geometry · Mathematics 2025-10-01 Shuwen Chen , Fangyang Zheng