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Related papers: Non-K\"ahler complex structures on $R^4$

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We study the problem of existence of geometric structures on compact complex surfaces that are related to split quaternions. These structures, called para-hypercomplex, para-hyperhermitian and para-hyperk\"ahler are analogs of the…

Differential Geometry · Mathematics 2015-06-05 Johann Davidov , Gueo Grantcharov , Oleg Mushkarov , Miroslav Yotov

In this paper, we review or introduce several differential structures on manifolds in the general setting of real and complex differential geometry, and apply this study to Teichm\"uller theory. We focus on bi-Lagrangian i.e. para-K\"ahler…

Differential Geometry · Mathematics 2020-08-25 Brice Loustau , Andrew Sanders

In this article we introduce the notion of Polyhedral Kahler manifolds, even dimensional polyhedral manifolds with unitary holonomy. We concentrate on the 4-dimensional case, prove that such manifolds are smooth complex surfaces, and…

Differential Geometry · Mathematics 2016-08-04 Dmitri Panov

We construct local models of isolated singularities for special K\"ahler structures in real dimension two assuming that the associated holomorphic cubic form does not have essential singularities. As an application we compute the holonomy…

Differential Geometry · Mathematics 2019-10-24 Martin Callies , Andriy Haydys

In the paper we consider pseudo bihermitian structures - a pair of complex structures compatible with a pseudo Riemannian metric. As in the positive definite case we establish its relations with generalized (pseudo) Kaehler geometry and…

Differential Geometry · Mathematics 2011-04-22 J. Davidov , G. Grantcharov , O. Muskarov , M. Yotov

The K\"ahler rank of compact complex surfaces was introduced by Harvey and Lawson in their 1983 paper on K\"ahler manifolds as a measure of ``k\"alerianity''. Here we give a partial classification of compact complex surfaces of K\"ahler…

Complex Variables · Mathematics 2010-10-14 Ionut Chiose , Matei Toma

This paper deals with complex structures on Lie algebras $\ct_{\pi} \hh=\hh \ltimes_{\pi} V$, where $\pi$ is either the adjoint or the coadjoint representation. The main topic is the existence question of complex structures on $\ct_{\pi}…

Differential Geometry · Mathematics 2009-03-02 Rutwig Campoamor Stursberg , Gabriela P. Ovando

Building on the now established presentation of the standard Podles sphere as an example of a noncommutative complex structure, we investigate how its classical Kahler geometry behaves under $q$-deformation. Discussed are noncommutative…

Quantum Algebra · Mathematics 2014-01-09 Réamonn Ó Buachalla

Given a semi-Riemannian $4$-manifold $(M,g)$ with two distinguished vector fields satisfying properties determined by their shear, twist and various Lie bracket relations, a family of K\"ahler metrics $g_K$ is constructed, defined on an…

Differential Geometry · Mathematics 2020-12-23 Amir Babak Aazami , Gideon Maschler

On $4$-symmetric symplectic spaces, invariant almost complex structures -- up to sign -- arise in pairs. We exhibit some $4$-symmetric symplectic spaces, with a pair of "natural" compatible (usually not positive) invariant almost complex…

Differential Geometry · Mathematics 2022-06-14 Michel Cahen , Simone Gutt , Manar Hayyani , Mohammed Raouyane

We give an elementary proof of the fact that any 4-dimensional para-Hermitian manifold admits a unique para-Kaehler--Weyl structure. We then use analytic continuation to pass from the para-complex to the complex setting and thereby show any…

Differential Geometry · Mathematics 2012-10-26 Peter Gilkey , Stana Nikcevic

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

In this paper we describe QCH K\"ahler surfaces $(M,g,J)$ of generalized orthotoric type. We introduce a distinguished orthonormal frame on $(M,g)$ and give the structure equations for $(M,g,J)$. In the case when $I$ is conformally K\"ahler…

Differential Geometry · Mathematics 2022-11-18 Włodzimierz Jelonek

We discuss hypercomplex and hyperk\"ahler structures obtained from higher degree curves in complex spaces fibring over ${\mathbb{P}}^1$.

Differential Geometry · Mathematics 2014-07-22 Roger Bielawski

Four dimensional simply connected Lie groups admitting a pseudo K\"ahler metric are determined. The corresponding Lie algebras are modelized and the compatible pairs $(J,\omega)$ are parametrized up to complex isomorphism (where $J$ is a…

Differential Geometry · Mathematics 2007-05-23 Gabriela P. Ovando

We study complex non-K\"ahler manifolds with Hermitian metrics being locally conformal to metrics with special cohomological properties. In particular, we provide examples where the existence of locally conformal holomorphic-tamed…

Differential Geometry · Mathematics 2016-08-04 Daniele Angella , Luis Ugarte

We discuss the complex geometry of two complex five-dimensional K\"ahler manifolds which are homogeneous under the exceptional Lie group $G_2$. For one of these manifolds rigidity of the complex structure among all K\"ahlerian complex…

Differential Geometry · Mathematics 2020-11-12 D. Kotschick , D. K. Thung

A method for constructing explicit Calabi-Yau metrics in six dimensions in terms of an initial hyperkahler structure is presented. The equations to solve are non linear in general, but become linear when the objects describing the metric…

High Energy Physics - Theory · Physics 2012-05-16 Osvaldo P. Santillan

We study the generalized K\"ahler-Ricci flow on complex surfaces with nondegenerate Poisson structure, proving long time existence and convergence of the flow to a weak hyperK\"ahler structure.

Differential Geometry · Mathematics 2016-01-13 Jeffrey Streets

Using representations of Clifford algebras we construct indecomposable singular Riemannian foliations on round spheres, most of which are non-homogeneous. This generalizes the construction of non-homogeneous isoparametric hypersurfaces due…

Differential Geometry · Mathematics 2014-07-08 Marco Radeschi