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Related papers: 4-dimensional (para)-K\"ahler--Weyl structures

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Having fixed a Kaehler class and the unique corresponding hyperkaehler metric, we prove that all special Lagrangian submanifolds of an irreducible symplectic 4-fold X are bi-Lagrangian and that they are obtained by complex submanifolds via…

Differential Geometry · Mathematics 2007-05-23 Alessandro Arsie

Let $(G,g)$ be a 4-dimensional Riemannian Lie group with a 2-dimensional left-invariant, conformal foliation $\F$ with minimal leaves. Let $J$ be an almost Hermitian structure on $G$ adapted to the foliation $\F$. We classify such…

Differential Geometry · Mathematics 2022-01-12 Emma Andersdotter Svensson , Sigmundur Gudmundsson

A non-linear generalization of the Dirac operator in 4-dimensions, obtained by replacing the spinor representation with a hyperKahler manifold admitting certain symmetries, is considered. We show that the existence of a covariantly…

Differential Geometry · Mathematics 2016-08-25 Varun Thakre

In this paper, we consider left-invariant para-complex structures on six-dimensional nilpotent Lie groups. A complete list of six-dimensional nilpotent Lie groups that admit para-K\"{a}hler structures is obtained, explicit expressions for…

Differential Geometry · Mathematics 2022-08-16 Nikolay K. Smolentsev

We study nilpotent Lie algebras endowed with a complex structure and a quadratic structure which is pseudo-Hermitian for the given complex structure. We propose several methods to construct such Lie algebras and describe a method of double…

Rings and Algebras · Mathematics 2023-01-18 Mustapha Bachaou , Ignacio Bajo , Mohamed Louzari

We construct new complex-valued harmonic morphisms from Euclidean spaces from functions which are holomorphic with respect to Hermitian structures. In particular, we give the first global examples of complex-valued harmonic morphisms from…

dg-ga · Mathematics 2008-02-03 P. Baird , J. C. Wood

We study left-invariant generalized K\"ahler structures on almost abelian Lie groups, i.e., on solvable Lie groups with a codimension-one abelian normal subgroup. In particular, we classify six-dimensional almost abelian Lie groups which…

Differential Geometry · Mathematics 2021-02-09 Anna Fino , Fabio Paradiso

Nearly K\"{a}hler and K\"{a}hler-Codazzi type manifolds are defined in a very similar way. We prove that nearly K\"{a}hler type manifolds have sense just in Hermitian and para-Hermitian contexts, and that K\"{a}hler-Codazzi type manifolds…

Differential Geometry · Mathematics 2020-06-09 Fernando Etayo , Araceli deFrancisco , Rafael Santamaría

We consider complete nearly K\"ahler manifolds with the canonical Hermitian connection. We prove some metric properties of strict nearly K\"ahler manifolds and give a sufficient condition for the reducibility of the canonical Hermitian…

Differential Geometry · Mathematics 2007-05-23 Paul-Andi Nagy

4-dimensional spaces equipped with congruences of null strings are considered. It is assumed that a space admits a congruence of expanding self-dual null strings and its self-dual part of the Weyl tensor is algebraically degenerate.…

Mathematical Physics · Physics 2023-04-07 Adam Chudecki

Due to its rich structure and close connection with gauge theory, hyperk\"ahler manifolds have attracted increasing interest. Using infinite dimensional hyperk\"ahler reduction, Kronheimer proved that certain adjoint orbits of complexified…

Differential Geometry · Mathematics 2026-03-30 Dadi Ni , Kaichuan Qi

In dimension greater than four, we prove that if a Hermitian non-Kaehler manifold is of pointwise constant antiholomorphic sectional curvatures, then it is of constant sectional curvatures.

Differential Geometry · Mathematics 2007-07-23 Georgi Ganchev , Ognian Kassabov

Motivated by the rich geometry of conformal Riemannian manifolds and by the recent development of geometries modeled on homogeneous spaces $G/P$ with $G$ semisimple and $P$ parabolic, Weyl structures and preferred connections are introduced…

Differential Geometry · Mathematics 2007-05-23 Andreas Cap , Jan Slovak

Using the idea of a generalized Kaehler structure, which is a pair of commuting generalized complex structures, we construct bihermitian metrics on the projective plane and the product of two projective lines, and show that any such…

Differential Geometry · Mathematics 2009-11-11 Nigel Hitchin

We show the existence of strictly almost-Kahler anti-self-dual metrics on certain 4-manifolds by deforming scalar-flat Kahler metrics. On the other hand, we prove the non-existence of such metrics on certain other 4-manifolds by means of…

Differential Geometry · Mathematics 2015-11-25 Inyoung Kim

We consider four (real or complex) dimensional hyper-K\"ahler metrics with a conformal symmetry K. The three-dimensional space of orbits of K is shown to have an Einstein-Weyl structure which admits a shear-free geodesics congruence for…

Differential Geometry · Mathematics 2007-05-23 Maciej Dunajski , Paul Tod

Integrable hypercomplex structures with Hermitian and Norden metrics on Lie groups of dimension 4 are considered. The corresponding five types of invariant hypercomplex structures with hyper-Hermitian metric, studied by M.L. Barberis, are…

Differential Geometry · Mathematics 2014-04-15 Mancho Manev

We study generalized Kaehler manifolds for which the corresponding complex structures commute and classify completely the compact generalized Kaehler four-manifolds for which the induced complex structures yield opposite orientations.

Differential Geometry · Mathematics 2007-05-23 Vestislav Apostolov , Marco Gualtieri

We find geometric conditions on a four-dimensional Hermitian manifold endowed with a metric connection with totally skew-symmetric torsion under which the complex structure is a harmonic map from the manifold into its twistor space…

Differential Geometry · Mathematics 2021-07-05 Johann Davidov

We show that a para-Hermitian algebraic curvature model satisfies the para-Gray identity if and only if it is geometrically realizable by a para-Hermitian manifold. This requires extending the Tricerri-Vanhecke curvature decomposition to…

Differential Geometry · Mathematics 2009-02-11 M. Brozos-Vazquez , P. Gilkey , S. Nikcevic , R. Vazquez-Lorenzo