单位球上正规权Zygmund空间上的点乘子

设μ是[0,1)上的一个正规函数,该文刻划了C~n中单位球B上正规权Zygmund空间Z_μ(B)上的点乘子.给出了Z_μ(B)上乘子算子为有界算子或紧算子的充要条件.     

C~n中μ-Bloch空间上的原子分解

设μ和ν是[0,1)上的正规函数,本文讨论了单位球B上正规权Bloch型空间βμ(B)的几个问题.首先给出了βμ(B)函数的一种积分表示,接着证明了βμ(B)是一类正规权Bergman型空间A1ν(B)的对偶空间,最后给出了βμ(B)函数的原子分解.     

C～n中单位球上μ-Bloch函数的等价刻画

设μ是[0,1)上的正规函数,给出了C~n中单位球B上μ-Bloch空间β_μ中函数的几种刻画.证明了下列条件是等价的:(1)f∈β_μ;(2)f∈H(B)且函数μ(|z|)(1-|z|~2)~(γ-1)R~(α,γ)f(z)在B上有界;(3)f∈H(B)且函数μ(|z|)(1-|z|~2)~M_1-1M_1f/_zm(z)在B上有界,其中|m|=M_1;(4)f∈H(B)且函数μ(|z|)(1-|z|~2)M_2-1R~(M_2)f(z)在B上有界.     

单位球上Bloch型空间到F(p,q,s)空间的Volterra复合算子

记H(B)为C~n中单位球B上的解析函数空间.设φ为B到自身的解析映射,g∈H(B),μ为正规权,定义Volterra复合算子为(V_φ~gf)(z)=∫_0~1f(φ(tz))Rg(tz)dt/t.本文考虑Volterra复合算子V_φ~g从B_μ或B_(μ,0)空间到F(p,q,s)或F_0(p,q,s)空间上的有界性和紧性,得出了算子V_φ~g:B_μ(B_(μ,0))→F(p,q,s)或B_μ(B_(μ,0))→F_0(p,q,s)的紧性与有界性等价.同时,也给出了算子V_φ~g从B~α或B_0~α空间到F(p,q,s)或F_0(p,q,s)空间上的紧性和有界性刻画.     

Clifford分析中对偶的k-Hypergenic函数

研究了取值于实Clifford代数空间Cl_(n+1,0)(R)中对偶的k-hypergenic函数.首先,给出了对偶的k-hypergenic函数的一些等价条件,其中包括广义的Cauchy-Riemann方程.其次,给出了对偶的hypergenic函数的Cauchy积分公式,并且应用其证明了(1-n)-hypergenic函数的Cauchy积分公式.最后,证明了对偶的hypergenic函数的Cauchy积分公式右端的积分是U\Ω_2中对偶的hypergenic函数.     

带参数的Littlewood-Paley g_λ~*函数的交换子在Morrey空间上的紧性

本文给出了交换子[b,g_λ~(*,ρ)]在Morrey空间L~(p,α)(R~n)上的紧性特征,其中1p∞,0αn.更精确地说,证明了交换子[b,g_λ~(*,ρ)]是Morrey空间上紧算子的充要条件是b∈VMO(R~n),其中g_λ~(*,ρ)表示带参数的Littlewood-Paley g_λ~*函数.     

非齐型空间中一类满足Hrmander条件的Marcinkiewicz交换子估计

记μ为R~d上的非负Radon测度,且仅满足对固定的C_0>0和n∈(0,d],及所有的x∈R~d和r>0,μ(B(x,r))≤C_0r~n.作者建立了一类核函数满足H(o|¨)rmander条件的Marcinkiewicz积分与Lip_β(μ)(0<β)函数生成的交换子由L~p(μ)到L~q(μ),由L~p(μ)到Lip_(β-n/p)(μ)及L~(n/β)(μ)到RBMO(μ)有界.部分结论对经典Marcink(?)ewicz积分也是新的.     

齐型空间上的加权 H~p(ω)和对偶

设 X 是一个齐型空间,R.R.Coifman 和 G.Weiss 在[1]中定义 H~(p,q)(X)为 Lipschitz 空间(?)_α(α=1/p-1)的对偶空间(?)_α~*的子空间,且每个元素有原子分解.对带权ω情形,用什么空间去代替与 q 无关的(?)_α?本文首先证明了带权ω的 Campanto 空间的一个重要性质以 ∧_(p,q)(ω)=∧_(p,q_1)(ω)(0r_0),由此我们给出了 H~p(ω)的定义;最后证明了 H~p(ω)的对偶是带权ω的 Campanto 空间 ∧_p(ω).     

非齐次粗糙核参数型Marcinkiewicz算子的H~p有界性

设Ω是球面上函数,b是径向函数,ρ是实部正的复数;设Ψ为C~2([0,∞))的递增凸函数,Ψ(0)=0.本文研究非齐次粗糙核参数型Marcinkiewicz算子μ_(Ω,b)~ρ,以及旋转曲面上的非齐次粗糙核参数型Marcinkiewicz算子μ_(Ω,Ψ,b)~ρ,给出非齐次粗糙核Ω和b的最小光滑性条件,建立算子μ_(Ω,b)~ρ和μ_(Ω,Ψ,b)~ρ在Hardy空间和弱Hardy空间上的有界性.本文结果推进了先前b≡1情形的已有工作.     

齐型空间上的加权 H~p(ω)和对偶

设 X 是一个齐型空间,R.R.Coifman 和 G.Weiss 在[1]中定义 H~(p,q)(X)为 Lipschitz 空间(?)_α(α=1/p-1)的对偶空间(?)_α~*的子空间,且每个元素有原子分解.对带权ω情形,用什么空间去代替与 q 无关的(?)_α?本文首先证明了带权ω的 Campanto 空间的一个重要性质以 ∧_(p,q)(ω)=∧_(p,q_1)(ω)(0r_0),由此我们给出了 H~p(ω)的定义;最后证明了 H~p(ω)的对偶是带权ω的 Campanto 空间 ∧_p(ω).     

非齐型空间上分数型Marcinkiewicz积分算子的加权估计

令（X，d，μ）为满足所谓上倍双倍条件和几何双倍条件的度量测度空间.设M_β，ρ，q为（X，d，μ）上的分数型Marcinkiewicz积分算子.在本文中，作者证明了若β ∈[0，∞），ρ ∈（0，∞），q ∈（1，∞）且M_β，ρ，q在L²（μ）上有界，则M_β，ρ，q是从加权Lebesgue空间L^p（w）到加权弱Lebesgue空间L^p，∞（w）上有界和从加权Morrey空间L^p，κ，η（ω）到加权弱Morrey空间WL^p，κ，η（ω）上有界.     

Molecular Characterization of Anisotropic Musielak–Orlicz Hardy Spaces and Their Applications

Let A be an expansive dilation on R~n and φ:R~n× [0,∞)→[0,∞) an anisotropic Musielak–Orlicz function.Let H_A~φ(R~n) be the anisotropic Hardy space of Musielak–Orlicz type defined via the grand maximal function.In this article,the authors establish its molecular characterization via the atomic characterization of H_A~φ(R~n).The molecules introduced in this article have the vanishing moments up to order s and the range of s in the isotropic case(namely,A:=2I_(n×n)) coincides with the range of well-known classical molecules and,moreover,even for the isotropic Hardy space H~p(R~n)with p∈(0,1](in this case,A:=2I_(n×n),φ(x,t) :=t~p for all x∈R~n and t∈[0,∞)),this molecular characterization is also new.As an application,the authors obtain the boundedness of anisotropic Calderón–Zygmund operators from H_A~φ(R~n) to L~φ(R~n) or from H_A~φ(R~n) to itself.     

带多项式相位的高维振荡积分算子的有界性

考虑如下的振荡积分算子:T_(m,k,n)f(x):=∫_(R~n)e~(i(x_1~2+…+x_n~2))~m(y_1~2+…+y_n~2)~kf(y)dy,其中函数f为定义在R~n上的Schwartz函数,并且满足m,k0.本文给出算子T_(m,k,n).从L~p(R~n)(1≤p∞)到L~q(R~n)有界的一个充分必要条件.此外,我们还证明了算子T_(m,k,n)把L~1(R~n)映到C_0(R~n).     

Universal C*-algebras defined by completely bounded unital homomorphisms

Suppose A is a unital C*-algebra and r 1.In this paper,we define a unital C*-algebra C_(cb)*(A,r) and a completely bounded unital homomorphism α_r:A → C_(cb)*(A,r)with the property that C_(cb)*(A,r)=C*(α_r(A))and,for every unital C*-algebra B and every unital completely bounded homomorphism φ:A→ B,there is a(unique)unital *-homomorphism π:C_(cb)*(A,r)→B such thatφ=πoα_r.We prove that,if A is generated by a normal set {t_λ:λ∈Λ},then C_(cb)*(A,r)is generated by the set {α_r(t_λ):λ∈Λ}.By proving an equation of the norms of elements in a dense subset of C_(cb)*(A,r)we obtain that,if Β is a unital C*-algebra that can be embedded into A,then C_(cb)*(B,r)can be naturally embedded into C(cb)*(A,r).We give characterizations of C_(cb)*(A,r)for some special situations and we conclude that C_(cb)*(A,r)will be "nice" when dim(A)≤ 2 and "quite complicated" when dim(A)≥ 3.We give a characterization of the relation between K-groups of A and K-groups of C_(cb)*(A,r).We also define and study some analogous of C_(cb)*(A,r).     

A Bishop–Phelps–Bollobás Theorem for Asplund Operators

By characterizing Asplund operators through Fréchet differentiability property of convex functions, we show the following Bishop–Phelps–Bollobás theorem: Suppose that X is a Banach space,T : X → C(K) is an Asplund operator with ║T║= 1, and that x_0 ∈ S_X, 0 ε satisfy ║T(x_0)║ 1-ε~2/2.Then there exist x_ε∈ S_X and an Asplund operator S : X → C(K) of norm one so that ║S(x_ε)║ = 1, x_0-x_ε ε and ║T-S║ ε.Making use of this theorem, we further show a dual version of Bishop–Phelps–Bollobás property for a strong Radon–Nikodym operator T : ?_1 → Y of norm one: Suppose that y_0~*∈ S_(Y~*), ε≥ 0 satisfy T~*(y_0~*) 1-ε~2/2. Then there exist y_ε~*∈ S_(Y~*), x_ε∈(±e_n), y_ε∈ S_Y, and a strong Radon–Nikodym operator S : ?_1 → Y of norm one so that (ⅰ)║S(x_ε)║= 1;(ⅱ) S(x_ε) = y_ε;(ⅲ)║T-S║ ε;(ⅳ)║S~*(y_ε~*)║=y_ε~*, y_ε= 1;(ⅴ)║y_0~*-y_ε~*║ ε and (ⅵ)║T~*-S~*║ ε,where(e_n) denotes the standard unit vector basis of ?_1.     

Jacobi-Sobolev-type orthogonal polynomials: Second-order differential equation and zeros

We obtain an explicit expression for the Sobolev-type orthogonal polynomials {Q_n} associated with the inner product

, where p(x) = (1 − x)(1 + x)^β is the Jacobi weight function, ,β> − 1, A₁,B₁,A₂,B₂0 and p, q P, the linear space of polynomials with real coefficients. The hypergeometric representation (₆F₅) and the second-order linear differential equation that such polynomials satisfy are also obtained. The asymptotic behaviour of such polynomials in [−1, 1] is studied. Furthermore, we obtain some estimates for the largest zero of Q_n(x). Such a zero is located outside the interval [−1, 1]. We deduce his dependence of the masses. Finally, the WKB analysis for the distribution of zeros is presented.     

变量核奇异积分和分数次微分加权范不等式

用T和D^γ（0 ≤ γ ≤ 1）分别表示变量核奇异积分和分数次微分算子.T^*和T^#分别为T的共轭算子及拟共轭算子.利用球调和多项式展式，本文得到了TD^γ-D^γT和（T^*-T^#）D^γ在?^q，λ_ω（Rⁿ）上的有界性.同时也得到了变量核奇异积分的积T₁T₂和拟积T₁°T₂的加权范不等式.     

Weak convergence to the multiple Stratonovich integral

We have considered the problem of the weak convergence, as tends to zero, of the multiple integral processes

in the space , where fL²([0,T]ⁿ) is a given function, and {η(t)}_>0 is a family of stochastic processes with absolutely continuous paths that converges weakly to the Brownian motion. In view of the known results when n2 and f(t₁,…,t_n)=1_{t1<t2<<tn}, we cannot expect that these multiple integrals converge to the multiple Itô–Wiener integral of f, because the quadratic variations of the η are null. We have obtained the existence of the limit for any {η}, when f is given by a multimeasure, and under some conditions on {η} when f is a continuous function and when f(t₁,…,t_n)=f₁(t₁)f_n(t_n)1_{t1<t2<<tn}, with f_iL²([0,T]) for any i=1,…,n. In all these cases the limit process is the multiple Stratonovich integral of the function f.     

向量值哈代-洛伦茨空间

对于1r∞与巴拿哈空间B=L~r(Ω,F,μ),我们研究了欧几里得空间R~n上B-值缓分布构成的哈代-洛伦茨空间H~(p,q)(R~n,B)及哈代-洛伦茨空间之间的内插,其中0p∞和0q≤∞,获得了H~(p,q)(R~n,B)的一系列等价的刻画及其原子分解.若Ω={1},则H~(p,q)(R~n,B)=H~(p,q)(R~n)是经典的情形;若Ω=Z是整数集且μ是Z上的计数测度并且r=2,0p∞及q=∞,则H~(p,q)(R~n,B)=H~(p,∞)(R~n,e~2)转化为Grafakos和He在文[Weak Hardy spaces,Preprint,2014]中讨论的情形.     

一类粗糙核奇异积分算子的端点估计

设T_Ω是带粗糙核的Calderón-Zygmund奇异积分算子,I为任意真包含在单位圆周S~1上的闭圆弧.本文证明,若Ω支在I上并在I上单调,那么T_Ω是从Hardy空间H~1(R~2)到L~1(R~2)的有界算子当且仅当‖Ω‖_(LlogL(S~1))∞.