共查询到20条相似文献,搜索用时 92 毫秒
1.
李松 《数学物理学报(A辑)》1996,(3)
该文利用三对角无穷方阵修正Szasz-Kantorvich(以下简记S-K)算子与Baskakov-Kantorovich(以下简记B-K)算子.对于这两类修正的算子,我们得到了H.Herens和G.G.Lorentz型的结果以及在Lp(0)中逼近的正逆定理。 相似文献
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李松 《数学物理学报(A辑)》1996,16(3):344-352
该文利用三对角无穷方阵修正Szasz-Kantorvich(以下简记S-K)算子与Baskakov-Kantorovich(以下简记B-K)算子。对于这两类修正的算子,我们得到了H.Herens和G.G.Loreentz型的结果以及在Lp(0)中逼近的正逆定理。 相似文献
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设无挠Fuchs群T及其子群Г’对应的Poincar级数算子为,对于Г的Teichmller空间T(Г)中的任意一点[f],有相应的算子,其中Гf=fГf-1,从而的范数,为T(Г)上的函数.众所周知.本文证明了在整个没有小于1的上界 相似文献
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钮鹏程 《纯粹数学与应用数学》1998,14(1):17-22
对Heisenberg群Hn上重sub-Laplace算子的特征值问题L2u=λu,在Ω中,u=uγ=0,在Ω上,讨论了特征值的估计,这里ΩHn为有界域,具分片光滑边界,γ为Ω的单位外法向量. 相似文献
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Cui Lihong 《大学数学》1998,(1)
本文以多项式(1+x)Vn(x)Vn(x)=cos2n+12θcosθ2,x=cosθ的零点作为插值的节点,构造了一个Lagrange插值多项式算子过程Cn(f,x),给出了其逼近阶估计.同时证明Cn(f,x)亦满足Ditzian-Totik定理. 相似文献
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关于非线性Lipschitz算子的Soderlind猜想 总被引:2,自引:2,他引:0
设f是以L(f)为最小上界Lipschitz常数,以ρ(f)为谱域半径,以γ(f)为Gerschgorim域半径的有限维非线性Lipschitz算子,本文证明了“存在等价范数‖.‖^*使L^*(f)=r^*(f)的Soderlind猜想;给出反例否定了Soderlind的另一猜想:”存在等价范烤‖.‖ε使Lε使Lε(f)≤ρ(f)+δ的猜想。 相似文献
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Theequivalencebetweencontinuityandboundednessofthelinearoperatorsonageneralprobabilisticnormedlinearspace(briefly,PNspace)wasdiscussedundersomehypotheses([1],Theorem2.4).Thepurposeofthispaperistodiscusstheequivalenceinthemuchmoregeneralsettingbymeans… 相似文献
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§1. IntroductionIn[1,2],AronsonandWeinbergerhavestudiedsystematiclythescalarnonlineardiffu-sionequationinonespacevariableut=uxx+φ(u),(1.1)whereu=u(x,t)andφ(u)isanonlinearfunction.Equation(1.1)arisesinseveralapplica-tions;See[1,2]and[3]forinformationa… 相似文献
10.
Some Properties of Solutions for Viscous Cahn-Hilliard Equation 总被引:1,自引:0,他引:1
§1.IntroductionInthispaper,westudytheviscousCahn-Hiliardequationut+γΔ2u-kΔut=Δφ(u),(1.1)whicharisesfrommodelingthedynamic... 相似文献
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本文引入了一类新型非正规算子,即具复谱的u-标算子.证明了该类算子具有Jordan型分解,讨论了u-标算子与标型谱算子的关系,并通过例子说明了该类算子的构造. 相似文献
13.
类似与标型谱算子,U-标算子是否拟仿射相似于自伴算子是一“公开问题”.尽管对具纯离散谱的U-标算子答案是肯定的,但一般情况下并不成立.本文继续探讨这一问题,证明了U-标算子在一强范数拓扑意义下是Hermite算子,或者说U-标算子拟仿射相似于Hermite算子,并给出U-标算子是标型谱算子的充要条件. 相似文献
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This paper is concerned with the spectral properties of the unbounded upper triangular operator matrix with diagonal domain. Some sufficient and necessary conditions are given under which the essential spectrum, the Weyl spectrum and the Browder spectrum of such operator matrix, respectively, coincide with the union of the essential spectrum, the Weyl spectrum and the Browder spectrum of its diagonal entries. 相似文献
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In this paper we investigate the asymptotic spectrum and accumulation of a transport operator A in slab geometry with continuous energy, anisotropic scattering and inhomogeneous medium. In L^p (1 ≤ p 〈 +∞) space we show a series of new results for the asymptotic point spectrum and accumulation of A. 相似文献
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在Hilbert空间线性算子逼近论中,算子本质的孤立点通常是处理一些问题的主要障碍之一,本给出处理算子本质谱的孤立点的一般方法。 相似文献
18.
John Lott 《Geometriae Dedicata》2002,91(1):175-196
We analyze the limit of the spectrum of a geometric Dirac-type operator under a collapse with bounded diameter and bounded sectional curvature. In the case of a smooth limit space B, we show that the limit of the spectrum is given by the spectrum of a certain first-order differential operator on B, which can be constructed using superconnections. In the case of a general limit space X, we express the limit operator in terms of a transversally elliptic operator on a G-manifold X/ with X = X//G. As an application, we give a characterization of manifolds which do not admit uniform upper bounds, in terms of diameter and sectional curvature, on the k-th eigenvalue of the square of a Dirac-type operator. We also give a formula for the essential spectrum of a Dirac-type operator on a finite-volume manifold with pinched negative sectional curvature. 相似文献
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A model operator similar to the energy operator of a system with a nonconserved number of particles is studied. The essential spectrum of the operator is described, and under some natural conditions on the parameters it is shown that there are infinitely many eigenvalues lying below the bottom of the essential spectrum. 相似文献
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将点谱划分为四个部分,得到上三角无穷维Hamilton算子的点谱σ_p(H)关于虚轴对称的充要条件.在此基础上,结合无穷维Hamilton算子的谱结构,得到无穷维Hamilton算子剩余谱的完全描述,从而实现了利用其内部算子刻画剩余谱. 相似文献