THE ∂∂^(-)-BOCHNER FORMULAS FOR HOLOMORPHIC MAPPINGS BETWEEN HERMITIAN MANIFOLDS AND THEIR APPLICATIONS

In this paper,we derive some∂∂^(-)-Bochner formulas for holomorphic maps between Hermitian manifolds.As applications,we prove some Schwarz lemma type estimates,and some rigidity and degeneracy theorems.For instance,we show that there is no non-constant holomorphic map from a compact Hermitian manifold with positive(resp.non-negative)ℓ-second Ricci curvature to a Hermitian manifold with non-positive(resp.negative)real bisectional curvature.These theorems generalize the results[5,6]proved recently by L.Ni on Kähler manifolds to Hermitian manifolds.We also derive an integral inequality for a holomorphic map between Hermitian manifolds.

A SUBSOLUTION THEOREM FOR THE MONGE-AMPERE EQUATION OVER AN ALMOST HERMITIAN MANIFOLD

Let Ω⊆M be a bounded domain with a smooth boundary ∂Ω,where(M,J,g)is a compact,almost Hermitian manifold.The main result of this paper is to consider the Dirichlet problem for a complex Monge-Ampère equation on Ω.Under the existence of a C^(2)-smooth strictly J-plurisubharmonic(J-psh for short)subsolution,we can solve this Dirichlet problem.Our method is based on the properties of subsolutions which have been widely used for fully nonlinear elliptic equations over Hermitian manifolds.

Note on Almost Hermitian Manifolds

We give a necessary and sufficient condition for an almost Hermitian manifold to be a Kahler manifold. By making use of this condition, we give a new proof of Goldberg＇s theorem.

Some Connections in Almost Hermitian Manifold

The idea of this research is to study different types of connections in an almost Hermite manifold. The connection has been established between linear connection and Riemannian connection. Three new linear connections ∇1, ∇2, ∇3 are introduced. The necessary and sufficient condition for ∇1, ∇2, ∇3 to be metric is discussed. A new metric s* (X,Y) has been defined for (Mn,F,g*) and additional properties are discussed. It is also proved that for the quarter symmetric connection ∇ is unique in given manifold. The hessian operator with respect to all connections defined above has also been discussed.

Embeddings of Almost Hermitian Manifold in Almost Hyper Hermitian Manifold and Complex (Hypercomplex) Numbers in Riemannian Geometry

Tubular neighborhoods play an important role in differential topology. We have applied these constructions to geometry of almost Hermitian manifolds. At first, we consider deformations of tensor structures on a normal tubular neighborhood of a submanifold in a Riemannian manifold. Further, an almost hyper Hermitian structure has been constructed on the tangent bundle TM with help of the Riemannian connection of an almost Hermitian structure on a manifold M then, we consider an embedding of the almost Hermitian manifold M in the corresponding normal tubular neighborhood of the null section in the tangent bundle TM equipped with the deformed almost hyper Hermitian structure of the special form. As a result, we have obtained that any Riemannian manifold M of dimension n can be embedded as a totally geodesic submanifold in a Kaehlerian manifold of dimension 2n (Theorem 6) and in a hyper Kaehlerian manifold of dimension 4n (Theorem 7). Such embeddings are “good” from the point of view of Riemannian geometry. They allow solving problems of Riemannian geometry by methods of Kaehlerian geometry (see Section 5 as an example). We can find similar situation in mathematical analysis (real and complex).

The holomorphic d-scalar curvature on almost Hermitian manifolds

In this paper,we study the existence of conformal metrics with the constant holomorphic d-scalar curvature and the prescribed holomorphic d-scalar curvature problem on closed,connected almost Hermitian manifolds of dimension n>6.In addition,we obtain an application and a variational formula for the associated conformal invariant.

Monge–Ampère Type Equations on Almost Hermitian Manifolds

In this paper we consider the Monge–Ampère type equations on compact almost Hermitian manifolds.We derive C∞a priori estimates under the existence of an admissible C-subsolution.Finally,we obtain an existence result if there exists an admissible supersolution.

On Compact Hermitian Manifolds with Flat Gauduchon Connections

Given a Hermitian manifold （M-n,g）, the Gauduchon connections are the one parameter family of Hermitian connections joining the Chern connection and the Bismut connection. We will call△=（1-s/2）△c＋s/2△b the s-Gauduchon connection of M, where △c and △b are respectively the Chern and Bismut connections. It is natural to ask when a compact Hermitian manifold could admit a flat s-Gauduchon connection. This is related to a question asked by Yau. The cases with s = 0 （a flat Chern connection） or s = 2 （a flat Bismut connection） are classified respectively by Boothby in the 1950s or by the authors in a recent joint work with Q. Wang. In this article, we observe that if either s 〉 4＋2√3 ≈ 7.46 or s 〈 4- 2√3≈ 0.54 and s ≠ 0, then g is Kahler. We also show that, when n = 2, g is always Kahler unless s=2. Therefore non-Kahler compact Gauduchon fiat surfaces are exactly isosceles Hopf surfaces.

Dirichlet Problem for Hermitian-Einstein Equation over Almost Hermitian Manifold

In this paper, we investigate the Dirichlet problem for Hermitian-Einstein equation on complex vector bundle over almost Hermitian manifold, and we obtain the unique solution of the Dirichlet problem for Hermitian-Einstein equation.

Two theorems on cosymplectic hypersurfaces of six-dimensional Hermitian submanifolds of Cayley algebra

Proves that cosymplectic hypersurfaces of six dimensional Hermitian submanifolds of the octave algebra are ruled manifolds and establishes a necessary and sufficient condition for a cosymplectic hypersurface of Hermitian M 6 O  to be a minimal submanifold of M 6.

Curvature identities on almost Hermitian manifolds and applications

We systematically derive the Bianchi identities for the canonical connection on an almost Hermitian manifold.Moreover,we also compute the curvature tensor of the Levi-Civita connection on almost Hermitian manifolds in terms of curvature and torsion of the canonical connection.As applications of the curvature identities,we obtain some results about the integrability of quasi K¨ahler manifolds and nearly K¨ahler manifolds.

The deformed Hermitian-Yang-Mills equation on almost Hermitian manifolds

In this paper,we consider the deformed Hermitian-Yang-Mills equation on closed almost Hermitian manifolds.In the case of the hypercritical phase,we derive a priori estimates under the existence of an admissible C-subsolution.As an application,we prove the existence of solutions for the deformed Hermitian-Yang-Mills equation under the condition of existence of a supersolution.

Hermitian-Poisson Metrics on Flat Bundles over Complete Hermitian Manifolds

In this paper,the author solves the Dirichlet problem for Hermitian-Poisson metric equation√(-1)Λ_(ω)G_(H)=λId and proves the existence of Hermitian-Poisson metrics on flat bundles over a class of complete Hermitian manifolds.Whenλ=0,the HermitianPoisson metric is a Hermitian harmonic metric.

The U-Kenmotsu Hypersurfaces Axiom and Six-Dimensional Hermitian Submanifolds of Cayley Algebra

Six-dimensional Hermitian submanifolds of Cayley algebra are considered.It is proved that if such a submanifold of the octave algebta complies with the U-Kenmotsu hypersurfaces axiom,then it is Khlerian.

An explicit formula for the Webster torsion of a pseudo-hermitian manifold and its application to torsion-free hypersurfaces Dedicated to Professor Sheng GONG on the occasion of his 75th birthday

This paper gives an explicit formula for calculating the Webster pseudo torsion for a strictly pseudoconvex pseudo-hermitian hypersurface. As applications, we are able to classify some pseudo torsion-free hypersurfaces, which include real ellipsoids.

Optimal regularity of plurisubharmonic envelopes on compact Hermitian manifolds

In this paper, we prove the C^(1,1)-regularity of the plurisubharmonic envelope of a C^(1,1) function on a compact Hermitian manifold. We also present the examples to show this regularity is sharp.

两类特殊的双扭曲积埃尔米特流形

设(M_(1),g)和(M_(2),h)是两个埃尔米特流形,双扭曲积埃尔米特流形(f_(2)M_(1)×f_(1)M_(2),G)是赋予了扭曲积埃尔米特度量G=f_(2)^(2)g+f_(1)^(2)h的乘积流形M_(1)×M_(2),其中f_(1)和f_(2)分别是M_(1)和M_(2)上的正值光滑函数。文章给出双扭曲积埃尔米特流形的挠率表达式,得到双扭曲积埃尔米特流形是凯勒流形或平衡流形的充要条件,并在特定条件下给出双扭曲积埃尔米特流形满足弱爱因斯坦条件的充要条件。

On Some Recent Progress in Complex Geometry-the Area Related to Homogeneous Manifolds

In this article,we give a survey of some progress of the complex geometry,mostly related to the Lie group actions on compact complex manifolds and complex homogeneous spaces in the last thirty years.In particular,we explore some works in the special area in Di erential Geometry,Lie Group and Complex Homogeneous Space.Together with the special area in nonlinear analysis on complex manifolds,they are the two major aspects of my research interests.

On the Proper Holomorphic Mappings between Equidimensional Hartogs Domains over Hermitian Symmetric Manifolds

In this paper,we study a family of Hartogs domains fibred over Hermitian symmetric manifolds being a unit ball in C^(m).The aim of the present study is to establish the rigidity results about proper holomorphic mappings between two equidimensional Hartogs domains over Hermitian symmetric manifolds.In particular,we can fully determine its biholomorphic equivalence and automorphism group.

到近Hermitian流形的调和同态(英文)

设:M→N是从黎曼流形到近Hermitian流形的水平共形映射。以的dilation和N上的Lee形式表示的张力场,从而导出了判别为调和同态的准则。进一步给出了若干结构转移定理,其中之一为Watson型结果。