Compact operators and Toeplitz algebras on multiply-connected domains

If Ω is a smoothly bounded multiply-connected domain in the complex plane and S belongs to the Toeplitz algebra τ of the Bergman space of Ω, we show that S is compact if and only if its Berezin transform vanishes at the boundary of Ω. We also show that every element S in T, the C^?-subalgebra of τ generated by Toeplitz operators with symbols in H^∞(Ω), has a canonical decomposition for some R in the commutator ideal CT; and S is in CT iff the Berezin transform vanishes identically on the set M₁ of trivial Gleason parts.     

Toeplitz operators with BMO symbols of several complex variables

In this note we prove that the boundedness and compactness of the Toeplitz operator on the Bergman space L_a² (\mathbbB_n )L_a^2 (\mathbb{B}_n ) for several complex variables with a BMO¹ symbol is completely determined by the boundary behavior of its Berezin transform.     

Berezin transform and Toeplitz operators on harmonic Bergman spaces

For an operator which is a finite sum of products of finitely many Toeplitz operators on the harmonic Bergman space over the half-space, we study the problem: Does the boundary vanishing property of the Berezin transform imply compactness? This is motivated by the Axler-Zheng theorem for analytic Bergman spaces, but the answer would not be yes in general, because the Berezin transform annihilates the commutator of any pair of Toeplitz operators. Nevertheless we show that the answer is yes for certain subclasses of operators. In order to do so, we first find a sufficient condition on general operators and use it to reduce the problem to whether the Berezin transform is one-to-one on related subclasses.     

n维单位球面上的Toeplitz符号演算

探讨了C^n中单位球面S上Berezin变换和Toeplitz算子的性质,证明了由{Tφ,φ∈L^∞ （S）}所生成的C^＊-代数中算子T的符号恰好为单位球B上函数T（称为T的Berezin变换）的非切向边界值．此外,本文还得到了经典Toeplitz符号演算的有趣推广．     

Positivity of Toeplitz operators via Berezin transform

In this paper, we study positive Toeplitz operators on the Bergman space via their Berezin transforms. Surprisingly we show that the positivity of a Toeplitz operator on the Bergman space is not completely determined by the positivity of the Berezin transform of its symbol. In fact, we show that even if the minimal value of the Berezin transform of a quadratic polynomial of |z|$|z|$ on the unit disk is positive, the Toeplitz operator with the function as the symbol may not be positive.     

Compact Operators on the Bergman Spaces of the Unit Ball and the Polydisk in C^n

Let Ω be the unit ban or the polydisk of C^n and La^2 (Ω) the Bergman space. In this paper we prove that if S is a finite sum of finite products of Toeplitz operators on La^2 (Ω), then S is compact if and only if the Berezin transform S↑-(z) of S tends to zero as z→эΩ.     

多重调和Bergman空间上的Toeplitz算子和Hankel算子

完全刻画多重调和Bergman空间上Toeplitz算子和Hankel算子的紧性.运用紧Toeplitz算子这个结果,建立了Toeplitz代数和小Hankel代数的短正合列,推广了单位圆盘上相应的结果.     

Bergman空间上的斜Toeplitz算子

本文讨论了Bergman空间上斜Toeplitz算子的若干性质,证明了:如果线性算子S在每个Lap(1相似文献   

A question of Toeplitz operators on the harmonic Bergman space

Choe and Lee [B.R. Choe, Y.J. Lee, Commuting Toeplitz operators on the harmonic Bergman space, Michigan Math. J. 46 (1999) 163-174] put the question: If an analytic Toeplitz operator and a co-analytic Toeplitz operator on the harmonic Bergman space commute, then is one of their symbols constant? If one of their symbols is bounded, then we will show that the answer is yes.     

高维加权Bergman空间上的Toeplitz算子

本文研究了高维加权Bergman空间Ap(Bn,dVpφ)(1＜p＜∞).上的Toeplitz算子.利用Toeplitz算子的Berezin变换,获得了Ap(Bn,dVp)(1＜p＜∞)上具有L∞(Bn)符号的Toeplitz算子的有限乘积的有限和是紧算子的一些等价刻画,推广了加权Bergman空间Ap(D,dmpφ)上的Toeplitz算子的有限乘积的有限和是紧的当且仅当它的Berezin变换在单位圆盘的边界消失为0的结论     

A~p()上的Toeplitz算子与Berezin变换

讨论了加权Bergman空间AP（）（1＜p＜∞）上的Toeplitz算子证明了Toeplitz算子的有限乘积的有限和是紧算子当区仅当其Berezin变换在边界趋向于零．     

加权Bergman空间上的紧算子

本文讨论了加权Ｂｅｒｇｍａｎ空间上的Ｔｏｅｐｌｉｔｚ算子,证明了Ｔｏｐｌｉｔｚ算子的有限乘积的有限和是紧的当且仅当它的Ｂｅｒｅｚｉｎ变换在边界上趋向于零．     

Toeplitz operators with BMO symbols on the weighted Bergman space of the unit ball

In this paper we prove that the boundedness and compactness of Toeplitz operator with a BMO _α ¹ symbol on the weighted Bergman space A _α ²(B _n ) of the unit ball is completely determined by the behavior of its Berezin transform, where α > −1 and n ≥ 1.     

多圆盘上的交换对偶Toeplitz算子

We completely characterize commutativity of Sρ and Sψ on L2α (Dn)⊥ for bounded pluriharmonic symbols ρ and ψ on Dn, and prove that SρSψ=Sψρ if and only if ρ is analytic or ψ is analytic.     

Bergman空间上拟齐次Toeplitz算子的乘积

使用Mellin变换作为工具,讨论了Bergman空间上以拟齐次函数为符号的Toeplitz算子的乘积问题,得出了当拟齐次函数的度处于三种不同情况时两个Toeplitz算子乘积仍是Toeplitz算子的充分必要条件.     

Analytic Toeplitz algebras and the Hilbert transform associated with a subdiagonal algebra

Let M be aσ-finite von Neumann algebra and let AM be a maximal subdiagonal algebra with respect to a faithful normal conditional expectationΦ.Based on the Haagerup’s noncommutative Lpspace Lp(M)associated with M,we consider Toeplitz operators and the Hilbert transform associated with A.We prove that the commutant of left analytic Toeplitz algebra on noncommutative Hardy space H2(M)is just the right analytic Toeplitz algebra.Furthermore,the Hilbert transform on noncommutative Lp(M)is shown to be bounded for 1p∞.As an application,we consider a noncommutative analog of the space BMO and identify the dual space of noncommutative H1(M)as a concrete space of operators.     

有限秩Toeplitz算子的(半)换位子

获得了Bergman空间上形如(T_f,T_g]-T_(h~n)和[T_f,T_g]-T_(h~n)的算子为有限秩时的充要条件,其中f,g,h均为有界调和函数,n为非负自然数.     

Diagonal invariant ideals of Toeplitz algebras on discrete groups

Diagonal invariant ideals of Toeplitz algebras defined on discrete groups are introduced and studied. In terms of isometric representations of Toeplitz algebras associated with quasi-ordered groups, a character of a discrete group to be amenable is clarified. It is proved that whenG is Abelian, a closed twosided non-trivial ideal of the Toeplitz algebra defined on a discrete Abelian ordered group is diagonal invariant if and only if it is invariant in the sense of Adji and Murphy, thus a new proof of their result is given.