Let u(z) be a real_valued harmonic function in the unit disk, we say u(z)∈h p(1【p【+∞), if the p _mean M p(r,u)=12π∫ 2π 0|u(re i θ )| p d θ 1/p is bounded. M.Riesz showed ...Let u(z) be a real_valued harmonic function in the unit disk, we say u(z)∈h p(1【p【+∞), if the p _mean M p(r,u)=12π∫ 2π 0|u(re i θ )| p d θ 1/p is bounded. M.Riesz showed that if u(z)∈h p(1【p【+∞), then there exists a constant A p, depending only on p such that M p(r,v)≤A pM p(r,u), where v(z) is the conjugate harmonic function of u(z).When v(0)=0 and 1【p≤2, W.K.Hayman showed that A p can be given by pp-1 1/p . First, this paper shows that the constant pp-1 1/p can be changed by a smaller constant pp-1 2/p -1 1/2 . Next, if 1【p≤2, then there exists a constant θ 0∈2-p2pπ,π2p such that M p p(r,v)≤ Im p sin pπ2+ tg pπ2pM p p(r,u) for any analytic function f(z)=u(z)+ i v(z) in the unit disk, whenever -θ 0【 arg f(z)【π2.展开更多
The vector sampling theorem has been investigated and widely used by multi-channel deconvolution, multi-source separation and multi-input multi-output （MIh40） systems. Commonly, for most of the results on MIMO syste...The vector sampling theorem has been investigated and widely used by multi-channel deconvolution, multi-source separation and multi-input multi-output （MIh40） systems. Commonly, for most of the results on MIMO systems, the input signals are supposed to be band-limited. In this paper, we study the vector sampling theorem for the wavelet subspaces with reproducing kernel. The case of uniform sampling is discussed, and the necessary and sufficient conditions for reconstruction are given. Examples axe also presented.展开更多
The weak-type (1, 1) boundedness of the higher order Riesz-Laguerre transforms associated with the Laguerre polynomials and the boundedness for the Riesz-Laguerre transforms of order 2 are considered. We discuss a pol...The weak-type (1, 1) boundedness of the higher order Riesz-Laguerre transforms associated with the Laguerre polynomials and the boundedness for the Riesz-Laguerre transforms of order 2 are considered. We discuss a polynomial weight w that makes the Riesz-Laguerre transforms of order greater than or equal to 2 continuous from L<sup>1</sup> (wdμ<sub>α</sub>) into L<sup>1,∞</sup> (dμ<sub>α</sub>), under specific value α, where μα</sub> is the Laguerre measure.展开更多
该文描述带有矩量序列{v_m}_0~∞■C^(q×q)的完全不确定Hamburger矩阵矩量问题:v_m=integral from n=-∞to∞x^m dρ(x),m=0,1,…的有限阶解,即该问题的那些解ρ,使得C^(q×q)-值多项式的线性空间P在对应的空间L^2(R,dρ/E(x)...该文描述带有矩量序列{v_m}_0~∞■C^(q×q)的完全不确定Hamburger矩阵矩量问题:v_m=integral from n=-∞to∞x^m dρ(x),m=0,1,…的有限阶解,即该问题的那些解ρ,使得C^(q×q)-值多项式的线性空间P在对应的空间L^2(R,dρ/E(x))内稠密,这里E(x)为在实轴R上取正值的某个数值多项式.作为预备知识,作者考虑所谓广义Akhiezer插值的矩阵变种与它的相关矩阵矩量问题之间的一种关系.展开更多
文摘Let u(z) be a real_valued harmonic function in the unit disk, we say u(z)∈h p(1【p【+∞), if the p _mean M p(r,u)=12π∫ 2π 0|u(re i θ )| p d θ 1/p is bounded. M.Riesz showed that if u(z)∈h p(1【p【+∞), then there exists a constant A p, depending only on p such that M p(r,v)≤A pM p(r,u), where v(z) is the conjugate harmonic function of u(z).When v(0)=0 and 1【p≤2, W.K.Hayman showed that A p can be given by pp-1 1/p . First, this paper shows that the constant pp-1 1/p can be changed by a smaller constant pp-1 2/p -1 1/2 . Next, if 1【p≤2, then there exists a constant θ 0∈2-p2pπ,π2p such that M p p(r,v)≤ Im p sin pπ2+ tg pπ2pM p p(r,u) for any analytic function f(z)=u(z)+ i v(z) in the unit disk, whenever -θ 0【 arg f(z)【π2.
基金supported by the National Natural Science Foundation of China (Grant No.60873130)the Shanghai Leading Academic Discipline Project (Grant No.J50104)
文摘The vector sampling theorem has been investigated and widely used by multi-channel deconvolution, multi-source separation and multi-input multi-output （MIh40） systems. Commonly, for most of the results on MIMO systems, the input signals are supposed to be band-limited. In this paper, we study the vector sampling theorem for the wavelet subspaces with reproducing kernel. The case of uniform sampling is discussed, and the necessary and sufficient conditions for reconstruction are given. Examples axe also presented.
文摘The weak-type (1, 1) boundedness of the higher order Riesz-Laguerre transforms associated with the Laguerre polynomials and the boundedness for the Riesz-Laguerre transforms of order 2 are considered. We discuss a polynomial weight w that makes the Riesz-Laguerre transforms of order greater than or equal to 2 continuous from L<sup>1</sup> (wdμ<sub>α</sub>) into L<sup>1,∞</sup> (dμ<sub>α</sub>), under specific value α, where μα</sub> is the Laguerre measure.
文摘该文描述带有矩量序列{v_m}_0~∞■C^(q×q)的完全不确定Hamburger矩阵矩量问题:v_m=integral from n=-∞to∞x^m dρ(x),m=0,1,…的有限阶解,即该问题的那些解ρ,使得C^(q×q)-值多项式的线性空间P在对应的空间L^2(R,dρ/E(x))内稠密,这里E(x)为在实轴R上取正值的某个数值多项式.作为预备知识,作者考虑所谓广义Akhiezer插值的矩阵变种与它的相关矩阵矩量问题之间的一种关系.
