English
Related papers

Related papers: Holomorphic harmonic morphisms from cosymplectic a…

200 papers

We classify six-dimensional homogeneous nearly K\"{a}hler manifolds and give a positive answer to Gray and Wolf's conjecture: every homogeneous nearly K\"{a}hler manifold is a Riemannian 3-symmetric space equipped with its canonical almost…

Differential Geometry · Mathematics 2007-05-23 Jean-Baptiste Butruille

In this paper we discuss the geometry of homogeneous spaces witch are almost Hermitian submanifolds of flag manifolds. We prove that such spaces are necessarily minimal submanifolds and in the case where these submanifolds are also flag…

Differential Geometry · Mathematics 2024-06-19 Neiton Pereira da Silva

In this paper we study invariant almost Hermitian geometry on generalized flag manifolds which the isotropy representation decompose into two or three irreducible components. We will provide a classification of such flag manifolds admitting…

Differential Geometry · Mathematics 2022-11-10 Lino Grama , Ailton R. Oliveira

We consider manifolds equipped with a foliation $\cal F$ of codimension $4q$, and an almost quaternionic structure $Q$ on the transversal bundle of ${\cal F}$. After discussing conditions of projectability and integrability of $Q$, we study…

Differential Geometry · Mathematics 2007-05-23 Paolo Piccinni , Izu Vaisman

We consider the existence of symplectic and conformal symplectic codimension-one foliations on closed manifolds of dimension at least 5. Our main theorem, based on a recent result by Bertelson-Meigniez, states that in dimension at least 7…

Symplectic Geometry · Mathematics 2021-11-02 Fabio Gironella , Lauran Toussaint

We introduce certain homology and cohomology subgroups for any almost complex structure and study their pureness, fullness and duality properties. Motivated by a question of Donaldson, we use these groups to relate J-tamed symplectic cones…

Symplectic Geometry · Mathematics 2009-09-15 Tian-Jun Li , Weiyi Zhang

We obtain a topological interpretation for the space of $L^2$ harmonic forms for some complete Riemannian manifold : when the geometry at infinity is the geometry of a simply connected nilpotent Lie group, when the geometry at infinity is a…

Differential Geometry · Mathematics 2007-05-23 Gilles Carron

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 study the integrability of a (almost) complex structure calibrated by a symplectic form. We find new sufficent conditions.

Symplectic Geometry · Mathematics 2014-05-26 Luigi Vezzoni

In this work we introduce a new method for the construction of minimal submanifolds of codimension two in even dimensional spheres and hyperbolic spaces. This is based on the theory of complex-valued harmonic morphisms. This gives the first…

Differential Geometry · Mathematics 2026-03-26 Sigmundur Gudmundsson , Leonard Nygren Löhndorf

Let Y be an infinite covering space of a projective manifold M in P^N of dimension n geq 2. Let C be the intersection with M of at most n-1 generic hypersurfaces of degree d in P^N. The preimage X of C in Y is a connected submanifold. Let…

Complex Variables · Mathematics 2007-05-23 Finnur Larusson

For every diffeomorphism $\varphi:M\to N$ between 3--dimensional Riemannian manifolds $M$ and $N$ there are in general locally two 2--dimensional distributions $D_{\pm}$ such that $\varphi$ is conformal on both of them. We state necessary…

Differential Geometry · Mathematics 2008-12-09 Kamil Niedzialomski

In this paper, a lot of examples of four-dimensional manifolds with an almost hypercomplex pseudo-Hermitian structure are constructed in several explicit ways. The received 4-manifolds are characterized by their linear invariants in the…

Differential Geometry · Mathematics 2012-05-08 Mancho Manev , Kouei Sekigawa

Let $X=U/K$ be a compact Hermitian symmetric space, and let $\sE$ be a $U$-homogeneous Hermitian vector bundle on $X$. In a previous paper, we showed that the space of nearly holomorphic sections is well-adapted for harmonic analysis in…

Complex Variables · Mathematics 2013-03-13 Benjamin Schwarz

In this note, we show that for a closed almost-K\"{a}hler manifold $(X,J)$ with the almost complex structure $J$ satisfies $\dim\ker P_{J}=b_{2}-1$ the space of de Rham harmonic forms is contained in the space of symplectic-Bott-Chern…

Differential Geometry · Mathematics 2021-08-31 Teng Huang

We consider the reduced twistor space $Z$ of an almost Hermitian manifold $M$, after O'Brian and Rawnsley (Ann. Global Anal. Geom., 1985). We concentrate on dimension 6. This space has a natural almost complex structure $\mathcal J$…

Differential Geometry · Mathematics 2007-05-23 Jean-Baptiste Butruille

We give conditions on the Lee vector field of an almost Hermitian manifold such that any holomorphic map from this manifold into a (1,2)-symplectic manifold must satisfy the fourth-order condition of being biharmonic, hence generalizing the…

Differential Geometry · Mathematics 2012-04-11 M. Benyounes , E. Loubeau , R. Slobodeanu

In this paper we study the hemi-slant submanifolds of cosymplectic manifolds. Necessary and sufficient conditions for distributions to be integrable are worked out. Some important results are obtained in this direction.

Differential Geometry · Mathematics 2016-03-07 Mehraj Ahmad Lone , Mohamd Saleem Lone , Mohammad Hasan Shahid

On non-K\"ahler manifolds the notion of harmonic maps is modified to that of Hermitian harmonic maps in order to be compatible with the complex structure. The resulting semilinear elliptic system is {\it not} in divergence form. The case of…

Differential Geometry · Mathematics 2009-02-27 Hans-Christoph Grunau , Marco Kuehnel

We give a condition for an almost constant-type manifold to be a constant-type manifold, and holomorphic and $R$-invariant submanifolds of almost Hermitian manifolds are studied. Generalizations of some results in [5] are given.

Differential Geometry · Mathematics 2013-11-12 Hakan Mete Taştan