非交换H_p空间理论的若干进展

该文分两部分综述非交换H_p空间理论的研究背景、发展线路以及某些最新进展.第一部分介绍非交换Hardy空间理论,包括有限次对角代数的基本性质(如唯一正规态开拓性质、分解性质、对数模性、不变子空间性质等),Szeg与Riesz型分解定理和H~1-BMO对偶定理等.第二部分综述非交换H_p鞅空间理论,主要介绍各种非交换鞅不等式以及作者与合作者在非交换Hardy鞅空间原子分解方面获得的最新结果.该文还给出了非交换H_p空间理论有待解决的一些问题和潜在的发展方向.     

弱Hardy鞅空间与鞅的弱原子分解

定义了一些弱Hardy鞅空间和3种类型的弱原子. 它们与经典的H_p鞅论中的Hardy鞅空间和原子形成对应. 然后证明了弱Hardy鞅空间上的3个弱原子分解定理. 利用鞅的弱原子分解, 给出了弱Hardy鞅空间上的次线性算子有界的一个充分条件. 利用这个条件, 得到关于鞅的一系列弱H_p范数不等式和弱(p,p)型不等式, 以及各个弱Hardy鞅空间的连续嵌入关系. 这些不等式是经典的H_p鞅论中基本不等式的弱型对应.     

Hardy-Orlicz-Lorentz空间*

论文利用极大刻画方法介绍了带一般参数的Hardy空间.作为特殊情况, 它们包含了经典H^p空间, Hardy-Lorentz 空间H^p,^q和广义的Hardy-Lorentz空间H^p(φ).     

拟鞅的Fefferman不等式和对偶定理

本文讨论了拟鞅的Fefferman不等式和Hardy空间的对偶空间. 利用鞅的相关结果和Doob分解的方法, 把鞅的Fefferman不等式推广到拟鞅情形, 并描述了拟鞅的Hardy空间Ĥ_p在1 < p < ∞)时的对偶空间.     

关于复平面上H∞空间,βp空间以及β0p空间的几个问题

本文讨论了单位圆中Hardy空间H^∞到p-Bloch空间β^p的复合算子T_1,φ加权复合算子T_ψ,φ的有界性,也讨论了H^∞到小p-Bloch空间β₀^p的复合算子T_1,φ的有界性问题;另外还讨论了小p-Bloch空间到H^∞空间的点乘子及小p-Bloch空间上复合算子的紧性等.     

空间的几种超投影性质及其局部化

讨论Banach空间几种超投影性质(及其相应的局部化性质)之间的关系,证明了在Banach空间X自反的条件下,X是l_p-次投影空间的充要条件是X^*是l_p-超投影空间,X是局部l_p-次投影空间的充要条件是X^*是局部l_p-超投影空间,以及X是局部次投影空间的充要条件是X^*是局部超投影的。其中1/p+1/q=1(p>1,q>1)。     

加权Hardy空间的分子刻画

在加权的Hardy空间H^{p ,q,s} _w 上 ,建立了具有高阶消失矩的分子概念 ,并给出了其分子刻画 .作为应用 ,证明了Hilbert算子在H^{p ,q,s} _w 空间上的有界性     

Calderón-Zygmund算子在CHpq上的有界性

本文讨论了δ－Calderon－Zygmund算子以及θ（t）－Calderon－Zygmund算子在Hardy型空间CH_p^q上的有界性．     

Sobolev空间的实内插

本文求出了Sobolev空间L_k^∞,BMO_k与L_k^p,H_k^p(0 < p < ∞)之间的实内插空间.     

QK空间的插值序列

本文研究了Q_K空间的插值问题.利用复分析和调和分析的方法,获得了单位圆盘上的一个序列{z_n}是Q_K∩H^∞空间的插值序列的一个充分必要条件,推广了Q_p空间的部分结果.     

Orlicz-Hardy空间与BMO空间之间的鞅变换

以鞅变换为工具,刻画了Orlicz-Hardy鞅空间与BMO空间之间的相互关系.证明了如下结论:对任意上指标有限(等价于满足△_2-条件)的Young函数Φ,鞅f∈H_Φ{P_Φ,Q_Φ}的充分必要条件是,f是BMO∈{BMO_1,BMO_2}中某个鞅g的鞅变换.     

Distributional inequalities for noncommutative martingales

We establish distributional estimates for noncommutative martingales, in the sense of decreasing rearrangements of the spectra of unbounded operators, which generalises the study of distributions of random variables. Our results include distributional versions of the noncommutative Stein, dual Doob, martingale transform and Burkholder-Gundy inequalities. Our proof relies upon new and powerful extrapolation theorems. As an application, we obtain some new martingale inequalities in symmetric quasi-Banach operator spaces and some interesting endpoint estimates. Our main approach demonstrates a method to build the noncommutative and classical probabilistic inequalities in an entirely operator theoretic way.     

鞅的双权双&Phi|-函数极大不等式

该文研究了鞅Orlicz空间加权不等式, 主要包括弱(Φ₁,Φ₂) -型加权不等式和强(Φ₁,Φ₂) -型加权不等式. 讨论了这些不等式成立的充分必要条件.     

弱型空间的鞅不等式及其应用——纪念李国平院士吴新谋教授诞辰100周年

弱型空间是近年来调和分析与鞅论中倍受关注的研究方向, 该文就以下几方面介绍有关弱型鞅空间的研究工作:(1) Lorentz鞅空间的原子分解;(2) Orlicz鞅空间的强弱型加权不等式; (3) 弱Orlicz鞅空间与拟范数不等式; (4) 在Banach空间理论与二进域调和分析中的应用.     

BMO spaces associated with semigroups of operators

We study BMO spaces associated with semigroup of operators on noncommutative function spaces (i.e. von Neumann algebras) and apply the results to boundedness of Fourier multipliers on non-abelian discrete groups. We prove an interpolation theorem for BMO spaces and prove the boundedness of a class of Fourier multipliers on noncommutative L _p spaces for all 1 < p < ∞, with optimal constants in p.     

Atomic decomposition and interpolation for Hardy spaces of noncommutative martingales

We prove that atomic decomposition for the Hardy spaces h₁ and H₁ is valid for noncommutative martingales. We also establish that the conditioned Hardy spaces of noncommutative martingales hp and bmo form interpolation scales with respect to both complex and real interpolations.     

多圆盘上的H∞与广义加权Bloch空间之间的复合算子

设φ 是Cⁿ的开单位多圆盘上的全纯自映射,α > 0. 该文主要研究了多圆盘上的H^∞与广义加权Bloch空间B^α_log(Uⁿ)之间的复合算子C_φ的有界性与紧性.     

Measures from Dixmier traces and zeta functions

For L^∞-functions on a (closed) compact Riemannian manifold, the noncommutative residue and the Dixmier trace formulation of the noncommutative integral are shown to equate to a multiple of the Lebesgue integral. The identifications are shown to continue to, and be sharp at, L²-functions. For functions strictly in Lp, 1?p<2, symmetrised noncommutative residue and Dixmier trace formulas must be introduced, for which the identification is shown to continue for the noncommutative residue. However, a failure is shown for the Dixmier trace formulation at L¹-functions. It is shown the noncommutative residue remains finite and recovers the Lebesgue integral for any integrable function while the Dixmier trace expression can diverge. The results show that a claim in the monograph [J.M. Gracia-Bondía, J.C. Várilly, H. Figueroa, Elements of Noncommutative Geometry, Birkhäuser Adv. Texts, Birkhäuser, Boston, 2001], that the equality on C^∞-functions between the Lebesgue integral and an operator-theoretic expression involving a Dixmier trace (obtained from Connes' Trace Theorem) can be extended to any integrable function, is false. The results of this paper include a general presentation for finitely generated von Neumann algebras of commuting bounded operators, including a bounded Borel or L^∞ functional calculus version of C^∞ results in IV.2.δ of [A. Connes, Noncommutative Geometry, Academic Press, New York, 1994].     

Noncommutative residue for Heisenberg manifolds. Applications in CR and contact geometry

This paper has four main parts. In the first part, we construct a noncommutative residue for the hypoelliptic calculus on Heisenberg manifolds, that is, for the class of ΨHDO operators introduced by Beals-Greiner and Taylor. This noncommutative residue appears as the residual trace on integer order ΨHDOs induced by the analytic extension of the usual trace to non-integer order ΨHDOs. Moreover, it agrees with the integral of the density defined by the logarithmic singularity of the Schwartz kernel of the corresponding ΨHDO. In addition, we show that this noncommutative residue provides us with the unique trace up to constant multiple on the algebra of integer order ΨHDOs. In the second part, we give some analytic applications of this construction concerning zeta functions of hypoelliptic operators, logarithmic metric estimates for Green kernels of hypoelliptic operators, and the extension of the Dixmier trace to the whole algebra of integer order ΨHDOs. In the third part, we present examples of computations of noncommutative residues of some powers of the horizontal sublaplacian and the contact Laplacian on contact manifolds. In the fourth part, we present two applications in CR geometry. First, we give some examples of geometric computations of noncommutative residues of some powers of the horizontal sublaplacian and of the Kohn Laplacian. Second, we make use of the framework of noncommutative geometry and of our noncommutative residue to define lower-dimensional volumes in pseudohermitian geometry, e.g., we can give sense to the area of any 3-dimensional CR manifold endowed with a pseudohermitian structure. On the way we obtain a spectral interpretation of the Einstein-Hilbert action in pseudohermitian geometry.