English
Related papers

Related papers: Deformations of Nearly K\"{a}hler Structures

200 papers

Using examples of compact complex 3-manifolds which arise as twistor spaces, we show that the class of compact complex manifolds bimeromorphic to K\"ahler manifolds is not stable under small deformations of complex structure.

alg-geom · Mathematics 2008-02-03 Claude LeBrun , Yat-Sun Poon

The goal of this paper is to study the deformations of compact K\"ahler hyperbolic manifolds. We propose slightly modified versions of K\"ahler hyperbolicity as a tool to provide a first step towards investigating the deformation openness…

Algebraic Geometry · Mathematics 2025-08-28 Abdelouahab Khelifati

To a homotopy algebra one may associate its deformation complex, which is naturally a differential graded Lie algebra. We show that infinity quasi-isomorphic homotopy algebras have L-infinity quasi-isomorphic deformation complexes by an…

K-Theory and Homology · Mathematics 2013-12-17 Vasily Dolgushev , Thomas Willwacher

We study nearly-Kahler 6-manifolds equipped with a cohomogeneity-two Lie group action for which the principal orbits are coisotropic. If the metric is complete, then we show that this last condition is automatically satisfied, and both the…

Differential Geometry · Mathematics 2018-10-31 Jesse Madnick

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

Motivated by the geometry of Levi degenerate CR hypersurfaces, we define a pre-K\"ahler structure on a complex manifold as a pre-symplectic structure compatible with the almost complex structure, i.e. a closed (1,1)-form. Extending Freeman…

Differential Geometry · Mathematics 2025-05-16 Omid Makhmali , David Sykes

We survey some recent results and constructions of almost-K\"ahler manifolds whose curvature tensors have certain algebraic symmetries. This is an updated and corrected version of the (to be) published manuscript.

Differential Geometry · Mathematics 2007-05-23 Vestislav Apostolov , Tedi Draghici

We define the space of nearly holomorphic automorphic forms on a connected reductive group $G$ over $\mathbb{Q}$ such that the homogeneous space $G(\mathbb{R})^1/ K_\infty^\circ$ is a Hermitian symmetric space. By Pitale, Saha and Schmidt's…

Number Theory · Mathematics 2019-12-11 Shuji Horinaga

We generalize the notions of the Futaki invariant and extremal vector field of a compact K\"ahler manifold to the general almost-Kahler case and show the periodicity of the extremal vector field when the symplectic form represents an…

Differential Geometry · Mathematics 2010-04-22 Mehdi Lejmi

A classification theorem for nearly K\"ahler manifolds of constant antiholomorphic sectional curvature is proved.

Differential Geometry · Mathematics 2010-09-15 Georgi Ganchev , Ognian Kassabov

In this paper, we study the existence of constant holomorphic d-scalar curvature and the prescribing holomorphic d-scalar curvature problem on closed, connected almost Hermitian manifolds of dimension $n\geq6$. In addition, we obtain an…

Differential Geometry · Mathematics 2023-02-27 Jianquan Ge , Yi Zhou

In this paper we consider left-invariant pseudo-K\"{a}hler structures on six-dimensional nilpotent Lie algebras. The explicit expressions of the canonical complex structures are calculated, and the curvature properties of the associated…

Differential Geometry · Mathematics 2013-11-15 N. K. Smolentsev

The Eichler-Shimura isomorphism describes a certain cohomology group with coefficients in a space of polynomials by using holomorphic modular/cusp forms. It determines a canonical decomposition of the corresponding de Rham cohomology group…

Algebraic Geometry · Mathematics 2023-09-22 Yasuhiro Wakabayashi

Let $(X,J,g,\omega)$ be a compact $2n$-dimensional almost-K\"ahler manifold. We prove primitive decompositions of $\partial$-, $\overline{\partial}$-harmonic forms on $X$ in bidegree $(1,1)$ and $(n-1,n-1)$ (such bidegrees appear to be…

Differential Geometry · Mathematics 2022-10-31 Andrea Cattaneo , Nicoletta Tardini , Adriano Tomassini

In this article we study the stability problem for positive quaternion-K\"ahler manifolds. We give a description of infinitesimal Einstein deformations and destabilising directions in terms of Laplace eigenfunctions and a special class of…

Differential Geometry · Mathematics 2026-04-03 Yasushi Homma , Uwe Semmelmann

We study the question of integrability of a compatible almost complex structure on a compact symplectic 4-manifold, under various natural assumptions on the curvature of the associated almost Kahler metric.

Differential Geometry · Mathematics 2007-05-23 Vestislav Apostolov , Tedi Draghici

We study the foliation space of complex and invariant (by torsion of intrinsic Hermitian connection) umbilic distribution on an isometric immersion from a nearly K\"ahler manifold $M$ into the Euclidean space. Under suitable conditions this…

Differential Geometry · Mathematics 2015-05-29 Nikrooz Heidari , Abbas Heydari

We classify, up to a local isometry, all non-Kahler almost Kahler 4-manifolds for which the fundamental 2-form is an eigenform of the Weyl tensor, and whose Ricci tensor is invariant with respect to the almost complex structure.…

Differential Geometry · Mathematics 2007-05-23 Vestislav Apostolov , John Armstrong , Tedi Draghici

We give a simple geometric description of all formal deformation quantizations on a K\"ahler manifold $M$ which enjoy the following property of separation of variables into holomorphic and antiholomorphic ones. For each open subset…

High Energy Physics - Theory · Physics 2015-04-21 Karabegov Alexander

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