Bergman空间的实变刻画

介绍复球上Bergman空间实变理论的某些新进展,包括Bergman空间关于Carleson矩形的实变原子分解,极大函数和面积函数刻画以及运用帐篷空间的实变刻画.特别是,用齐次空间上向量值Calderón-Zygmund奇异积分算子理论研究Bergman积分算子的Lp有界性并给出了Bergman空间面积积分刻画的新证明...     

A note on equilibrium points of Green's function

We answer a question raised by Ahmet Sebbar and Thérèse Falliero (2007) by showing that for every finitely connected planar domain there exists a compact subset , independent of , containing all critical points of Green's function of with pole at .

     

Construction of Green functions for weighted biharmonic operators

A constructive proof is given of the existence of the weighted biharmonic Green function Γ_α for α?0. The method is used to derive the explicit formula for Γ₁ previously stated by Hedenmalm. In addition, a formula for Γ₂ is found, which is then shown to take both positive and negative values in the bidisk .     

On the integral representation of superbiharmonic functions

We consider a nonnegative superbiharmonic function w satisfying some growth condition near the boundary of the unit disk in the complex plane. We shall find an integral representation formula for w in terms of the biharmonic Green function and a multiple of the Poisson kernel. This generalizes a Riesz-type formula already found by the author for superbihamonic functions w satisfying the condition 0 ⩽ w(z) ⩽ C(1-|z|) in the unit disk. As an application we shall see that the polynomials are dense in weighted Bergman spaces whose weights are superbiharmonic and satisfy the stated growth condition near the boundary. Research supported in part by IPM under the grant number 83310011.     

Boundary behavior of the Bergman kernel function on pseudoconvex domains with comparable Levi form

Let Ω be a smoothly bounded pseudoconvex domain in and let be a point of finite type. We also assume that the Levi form of bΩ is comparable in a neighborhood of z₀. Then we get a quantity which bounds from above and below the Bergman kernel function in a small constant and large constant sense.     

Commuting Toeplitz operators on the polydisk

We obtain characterizations of (essentially) commuting Toeplitz operators with pluriharmonic symbols on the Bergman space of the polydisk. We show that commuting and essential commuting properties are the same for dimensions bigger than 2, while they are not for dimensions less than or equal to 2. Also, the corresponding results for semi-commutators are obtained.

     

Bergman kernel and metric on non-smooth pseudoconvex domains

A stability theorem of the Bergman kernel and completeness of the Bergman metric have been proved on a type of non-smooth pseudoconvex domains defined in the following way:D = {z∈U|r(z)} <whereU is a neighbourhood of andr is a continuous plurisubharmonic function onU. A continuity principle of the Bergman Kernel for pseudoconvex domains with Lipschitz boundary is also given, which answers a problem of Boas.     

The harmonic Bergman kernels for punctured domains

We obtain the explicit formulae for the harmonic Bergman kernels of Bn／{0} and Rn／Bn and study the connection between harmonic Bergman kernel and weighted harmonic Bergman kernel.We also get the explicit formula for the weighted harmonic Bergman kernel of Bn／{0} with the weight 1/｜x｜4.     

Behavior of the Bergman kernel and metric near convex boundary points

The boundary behavior of the Bergman metric near a convex boundary point of a pseudoconvex domain is studied. It turns out that the Bergman metric at points in the direction of a fixed vector tends to infinity, when is approaching , if and only if the boundary of does not contain any analytic disc through in the direction of .

     

The Bergman kernel function of some Reinhardt domains (Ⅱ)

The boundary behavior of the Bergman kernel function of a kind of Reinhardt domain is studied. Upper and lower bounds for the Bergman kernel function are found at the diagonal points (Z,(Z-)). Let Ω be the Reinhardt domainm(X) where αj>0,j=1,2,…,n,N=N1+N2+…+Nn,‖Zj‖ is the standard Euclidean norm in CNj,j=1,2,…,n; and let K(Z,(W-)) be the Bergman kernel function of Ω. Then there exist two positive constants m and M,and a function F such that mF(Z,(Z-))≤K(Z,(Z-))≤MF(Z,(Z-))holds for every Z∈Ω. Here (X) and r(Z)=‖Z‖α-1 is the defining function of Ω. The constants m and M depend only on α=(α1,…,αn) and N1,N2,…,Nn,not on Z. This result extends some previous known results.     

Equivalent characterizations of <Emphasis Type="Italic">α</Emphasis>-Bloch functions on the unit ball

In this paper we establish equivalent characterizations of α-Bloch functions on the unit ball without use of derivative, which generalize and improve the results of Nowak, Zhao, Wulan and Li.     

The backward shift on Dirichlet-type spaces

We study the backward shift operator on Hilbert spaces (for ) which are norm equivalent to the Dirichlet-type spaces . Although these operators are unitarily equivalent to the adjoints of the forward shift operator on certain weighted Bergman spaces, our approach is direct and completely independent of the standard Cauchy duality. We employ only the classical Hardy space theory and an elementary formula expressing the inner product on in terms of a weighted superposition of backward shifts.

     

BERGMAN TYPE OPERATOR ON MIXED NORM SPACES WITH APPLICATIONS

ＢＥＲＧＭＡＮＴＹＰＥＯＰＥＲＡＴＯＲＯＮＭＩＸＥＤＮＯＲＭＳＰＡＣＥＳＷＩＴＨＡＰＰＬＩＣＡＴＩＯＮＳＲＥＮＧＵＡＮＧＢＩＮＳＨＩＪＩＨＵＡＩＡｂｓｔｒａｃｔＴｈｅａｕｔｈｏｒｓｉｎｖｅｓｔｉｇａｔｅｔｈｅｃｏｎｄｉｔｉｏｎｓｆｏｒｔｈｅｂｏｕ...     

A note on polyharmonic functions

In this note we prove the following theorem:Suppose 0<p<∞ and α>−1. Then there is a constant C=C(p,m,n,α) such that

     

实解析变换下Bergman核函数变换公式及其应用

利用形变理论研究实解析变换下(加权)Bergm an核函数变换公式,并利用这一公式从已知域的Bergm an核函数求得新的域的加权Bergm an核函数.我们的结果推广了经典的在双全纯映照下的Bergm an核函数变换公式.     

二连通域上Besov函数的等价刻划

定义了二连通城上Besov函数，探讨了Besov函数的等价刻划，即给了函数为Besov函数的若干充要条件．     

Composition operators that improve integrability on weighted Bergman spaces

Composition operators between weighted Bergman spaces with a smaller exponent in the target space are studied. An integrability condition on a generalized Nevanlinna counting function of the inducing map is shown to characterize both compactness and boundedness of such an operator. Composition operators mapping into the Hardy spaces are included by making particular choices for the weights.

     

Composition operators between Bergman and Hardy spaces

We study composition operators between weighted Bergman spaces. Certain growth conditions for generalized Nevanlinna counting functions of the inducing map are shown to be necessary and sufficient for such operators to be bounded or compact. Particular choices for the weights yield results on composition operators between the classical unweighted Bergman and Hardy spaces.