The index of singular integral operators in reflexive Orlicz spaces

We consider the Banach algebra of singular integral operators with matrix piecewise continuous coefficients in the reflexive Orlicz spaceL _M ⁿ (Γ). We assume that Γ belongs to a certain wide subclass of the class of Carleson curves; this subclass includes curves with cusps, as well as curves of the logarithmic spiral type. We obtain an index formula for an arbitrary operator from the algebra in terms of the symbol of this operator. Translated fromMatematicheskie Zametki, Vol. 64, No. 3, pp. 383–396, September, 1998.     

Cn中有界对称域上不同加权Dirichlet空间之间的复合算子

§１．　ＩｎｔｒｏｄｕｃｔｉｏｎＬｅｔΩｂｅａｂｏｕｎｄｅｄｓｙｍｍｅｔｒｉｃｄｏｍａｉｎｗｉｔｈｉｔｓｓｔａｎｄａｒｄｒｅａｌｉｚａｔｉｏｎｉｎＣｎａｎｄｎｏｒｍａｌｉｚｅｄ（Ｅｕｃｌｉｄｅａｎ）ｖｏｌｕｍｅｍｅａｓｕｒｅｓｏｔｈａｔυ（Ω）＝１．ＬｅｔＫ（·,ｚ）ｄｅｎｏｔｅｔｈｅＢｅｒｇｍａｎｋｅｒｎａｌｆｕｎｃ－ｔｉｏｎａｔｚ∈Ω．ＴｈｅＢｅｒｇｍａｎｍｅｔｒｉｃｏｎΩｉｓｄｅｆｉｎｅｄｂｙＧｚ＝（ｇｉｊ（ｚ））＝１２２ｚｉｚｊｌｏｇＫ（ｚ,ｚ）　１ｉ,ｊｎ．Ｉｆγ：［０,１］…     

一类多维实变Q-型空间的刻画

本文引入了一类Q-型空间Qκ,γ(Rn),利用Poisson积分得到了Qκ,γ(Rn)的Carleson型刻画.同时也得到了此类空间的小波刻画.     

Forelli-Rudin积分的帐篷嵌入与Qp到α-Bloch空间上的积分算子——纪念李国平院士吴新谋教授诞辰100周年

该文借助关于帐篷空间的嵌入定理与Carleson型测度特征刻画了复单位球上从Q_p空间到α-Bloch空间的广义Cesàro算子的有界性与紧性.     

Characterizations of Arveson's Hardy Space

A Hardy-type space H ² _d in the unit ball B_d of C^d , which was recently introduced by Arveson [W. Arveson (1998). Subalgebras of C*-algebras III: multivariable operator theory. Acta Math., 181, 159-228.], is appropriate for the operator theory of d-contractions. In this article, it is proved that H ² _d actually coincides with a Hardy-Sobolev space. This yields almost immediately some of the related results obtained in [W. Arveson (1998). Subalgebras of C*-algebras III: multivariable operator theory. Acta Math., 181, 159-228.], including the facts that H ² _d is not associated with any measure on C ^d ; and that the corresponding algebra of multipliers M ? H ^∞(B_d ) and the inclusion is proper. Finally, a function-theoretic version of von Neumann's inequality for the d-contractions is presented.     

New Orlicz-Hardy spaces associated with divergence form elliptic operators

Let L be the divergence form elliptic operator with complex bounded measurable coefficients, ω the positive concave function on (0,∞) of strictly critical lower type pω∈(0,1] and ρ(t)=t−1/ω−1(t−1) for t∈(0,∞). In this paper, the authors study the Orlicz-Hardy space Hω,L(Rn) and its dual space BMOρ,L^*(Rn), where L^* denotes the adjoint operator of L in L²(Rn). Several characterizations of Hω,L(Rn), including the molecular characterization, the Lusin-area function characterization and the maximal function characterization, are established. The ρ-Carleson measure characterization and the John-Nirenberg inequality for the space BMOρ,L(Rn) are also given. As applications, the authors show that the Riesz transform ∇L−1/2 and the Littlewood-Paley g-function gL map Hω,L(Rn) continuously into L(ω). The authors further show that the Riesz transform ∇L−1/2 maps Hω,L(Rn) into the classical Orlicz-Hardy space Hω(Rn) for and the corresponding fractional integral L−γ for certain γ>0 maps Hω,L(Rn) continuously into , where is determined by ω and γ, and satisfies the same property as ω. All these results are new even when ω(t)=tp for all t∈(0,∞) and p∈(0,1).     

Weighted interpolation in Paley-Wiener spaces and finite-time controllability

This paper considers the solution of weighted interpolation problems in model subspaces of the Hardy space H² that are canonically isometric to Paley-Wiener spaces of analytic functions. A new necessary and sufficient condition is given on the set of interpolation points which guarantees that a solution in H² can be transferred to a solution in a model space. The techniques used rely on the reproducing kernel thesis for Hankel operators, which is given here with an explicit constant. One of the applications of this work is to the finite-time controllability of diagonal systems specified by a C₀ semigroup.     

Embedding theorems and integration operators on Bergman spaces with rapidly decreasing weights

We completely describe those positive Borel measures μ in the unit disc D such that the Bergman space Ap(w)⊂Lq(μ), 0<p,q<∞, where w belongs to a large class W of rapidly decreasing weights which includes the exponential weights , α>0, and some double exponential type weights.As an application of that result, we characterize the boundedness and the compactness of Tg:Ap(w)→Aq(w), 0<p,q<∞, w∈W, where Tg is the integration operator

     

支撑在(-1, 1)上的Carleson型测度与Hankel 矩阵

In this paper, we establish a connection between Carleson type measures supported on(-1, 1) and certain Hankel matrices. The connection is given by the study of Hankel matrices acting on Dirichlet type spaces.