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Related papers: On the twistor space of pseudo-spheres

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In this paper we obtain several curvature properties of the twistor and reflector spaces of a paraquaternionic K\"{a}hler manifold and prove the existence of both positive and negative mixed 3-Sasakian structures in a principal…

Differential Geometry · Mathematics 2012-04-24 Gabriel Eduard Vilcu , Rodica Cristina Voicu

By a theorem of Kirchhoff if the six sphere admits an almost complex structure then the seven sphere is parallelizable, more crucial, he exhibited an explicit global frame constructed out of the given almost complex structure. This result…

Differential Geometry · Mathematics 2018-04-17 Lázaro O. Rodríguez Díaz

In contrast to the classical twistor spaces whose fibres are 2-spheres, we introduce twistor spaces over manifolds with almost quaternionic structures of the second kind in the sense of P. Libermann whose fibres are hyperbolic planes. We…

Differential Geometry · Mathematics 2007-05-23 D. E. Blair , J. Davidov , O. Mushkarov

In this expository paper we review some twistor techniques and recall the problem of finding compact differentiable manifolds that can carry both K\"ahler and non-K\"ahler complex structures. Such examples were constructed independently by…

Differential Geometry · Mathematics 2018-09-11 Ljudmila Kamenova

The aim of the paper is to investigate the rigidity and the deformability of pseudoholomorphic curves in the nearly K{\"a}hler sphere $\mathbb{S}^6,$ among minimal surfaces in spheres. Under various assumptions we describe the moduli space…

Differential Geometry · Mathematics 2023-01-10 Amalia-Sofia Tsouri

We explain in some detail the geometric structure of spheres in any dimension. Our approach may be helpful for other homogeneous spaces (with other signatures) such as the de Sitter and anti-de Sitter spaces. We apply the procedure to the…

General Physics · Physics 2013-11-13 G. Avila , S. J. Castillo , J. A. Nieto

The twistor space of a Riemannian 4-manifold carries two almost complex structures, $J_+$ and $J_-$, and a natural closed 2-form $\omega$. This article studies limits of manifolds for which $\omega$ tames either $J_+$ or $J_-$. This amounts…

Differential Geometry · Mathematics 2017-05-04 Joel Fine

In a previous paper the second author showed that if $M$ is a pseudomanifold with complementarity other than the 6-vertex real projective plane and the 9-vertex complex projective plane, then $M$ must have dimension $\geq 6$, and - in case…

Geometric Topology · Mathematics 2007-05-23 Bhaskar Bagchi , Basudeb Datta

In some other context, the question was raised how many nearly K\"ahler structures exist on the sphere $\S^6$ equipped with the standard Riemannian metric. In this short note, we prove that, up to isometry, there exists only one. This is a…

Differential Geometry · Mathematics 2007-05-23 Thomas Friedrich

The nearly K\"{a}hler structures on the 6-sphere, as a twistor bundle sections are researched. We show that for any point of twistor bundle there exists an 1-parametric family of sections, passing through the point, which give nearly…

Differential Geometry · Mathematics 2015-10-19 N. A. Daurtseva

For $n \geq 1$, the twistor space $\mathfrak{Z}(\mathbb{S}^{2n})$ of the conformal $2n$-sphere is biholomorphic to the Zariski closure, taken in the complex Grassmannian manifold $\mathbf{G}(n+1, 2n+2)$, of the set of graphs of…

Differential Geometry · Mathematics 2012-07-20 Elsa Puente , Alberto Verjovsky

We interpret an open orbit in a 32-dimensional representation space of Spin(9,1) x SL(2,R) as a substitute for the non-existent group of invertible 2x2 matrices over the octonions and study various natural homogeneous subspaces. The…

Differential Geometry · Mathematics 2018-05-08 Nigel Hitchin

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

We characterize HKT structure in terms of nondegenrate complex Poisson bivector on hypercomplex manifold. We extend the characterization to the twistor space. After considering the flat case in detail, we show that the twistor space of…

Differential Geometry · Mathematics 2015-05-20 Gueo Grantcharov , Lisandra Hernandez-Vazquez

This article is a survey about or introduction to certain aspects of the complex geometry of a hypothetical complex structure on the six-sphere. We discuss a result of Peternell--Campana--Demailly on the algebraic dimension of a…

Complex Variables · Mathematics 2019-12-23 Christian Lehn , Sönke Rollenske , Caren Schinko

Let $(M,J)$ be a $n$-dimensional complex manifold: a $p$-K\"ahler structure (resp. $p$-symplectic structure) on $M$ is a real, closed $(p,p)$-transverse form $\Omega$ (resp. real, closed $2p$-form whose $(p,p)$-component is transverse). We…

Differential Geometry · Mathematics 2024-07-17 Ettore Lo Giudice , Adriano Tomassini

Let M be a hyperk\"ahler manifold. The S^2-family of complex structures compatible with the hyperk\"ahler metric can be assembled into a single complex structure on Z=MxS^2; the resulting complex manifold is known as the twistor space of M.…

Differential Geometry · Mathematics 2015-12-01 Rebecca Glover , Justin Sawon

The twistor space of the moduli space of solutions of Hitchin's self-duality equations can be identified with the Deligne-Hitchin moduli space of $\lambda$-connections. We use real projective structures on Riemann surfaces to prove the…

Differential Geometry · Mathematics 2022-03-03 Sebastian Heller

We consider some classical fibre bundles furnished with almost complex structures of twistor type, deduce their integrability in some cases and study \textit{self-holomorphic} sections of a \textit{symplectic} twistor space. With these we…

Differential Geometry · Mathematics 2011-12-15 Rui Albuquerque

In a recent paper (math.DG/0701278) we constructed a series of new Moishezon twistor spaces which is a kind of variant of the famous LeBrun twistor spaces. In this paper we explicitly give projective models of another series of Moishezon…

Differential Geometry · Mathematics 2009-11-13 Nobuhiro Honda