C-等价充要条件的一个应用

在C^∞函数芽的奇点理论和突变论中,很多基本问题涉及到n个变元的函数芽环E_n中有限余维理想任一补空间一组基的计算。例如J.N.Maffler对有限余维的函数芽的universal deformation证明了下述基本定理:f的一个P——参数的deformation是universal,当且仅当它的初速度F_i(i=1,2,…,p)使得: J(f)+R{F₁,F₂,…,F_p}=E_{n相似文献}   

一类实奇芽等价的充要条件

给定一自反的Ｂａｎａｃｈ空间Ｘ．在ｃ^∞函数芽环∈（Ｘ）中,任何在原点Ｏ∈Ｘ的实奇芽ｆ,若其二阶Ｆｒｅｃｈｅｔ导数ｆ″（０）＝Ｔ是一个Ｆｒｅｄｈｏｌｍ算子,则它同构于形如：1/2+g(v)的一个芽．如果代替ｇ以一个与之同构的芽ｇ_１,显然得到一个与原来的芽同构的芽．然而,其逆是否真呢？本文将证明其逆命题亦真     

多元Szász—Mirkjan算子的一致逼近

本文研究了多元Szása—Mirakjan算子在C_2B(T)中的逼近性质,利用K—泛函,建立了等价的逼近定理.主要结果如下 定理设f∈C_2B(T),0a) ;(ii)‖S_n,m(f)-f‖_∞ =0(n^-a);(iii)a)‖f(x+tφ(x),y)-2f(x,y)+f(x-tφ(x),y)‖_∞ =0(t<     

关于P.Turán问题24,Ⅱ

在本文中我们得到了一个比[1]中更好的P.Turán问题24的答案:若Hermite—Fejér插值过程对于任何f∈C[-1,1]都一致收敛,则定义于同一组节点上的Lagrange插值过程对于每个f∈{f:E_n(f)=o(n^-(23)/(18)}都一致收敛,这里E_n(f)为f∈C[-1,1]的用次数≤n的代数多项式逼近的偏差.     

加权BMO函数空间上的Hardy－Littlewood极大算子

本文给出了Ｈａｒｄｙ－Ｌｉｔｔｌｅｗｏｏｄ极大函数和加权ＢＭＯ的有界性证明：即若f∈ＢＭＯ_w,w∈A_∞,且(?)Mf(x)<∞, 则M(f)(x) ∈BMO_w, 且‖Mf‖_w^*≤c‖f‖_w^*.     

映射的横截性定理

Hirsch conjectured: M、N、A are differential manifolds, g∈C^∞(A,N), then the set T = {f∈C^∞(M,N)|f∈g} is dense in C∞(M,N)and open if g is proper.In this paper, we prove the transversality theorem of map in the Jet bundle.Theorem 1 Let M, N. A be differential manifolds, g∈C^∞(A,J^τ(M、N)), then the set T{f∈C^∞(M,N)|f^τf∈g } is residual in C^∞(M,N) and open if g is proper.Theorem 1 contains Thom's transversal ity theorem as a special case. We can obtain Hirsch's conjecture by using theorem 1.     

球面上等收敛算子的有界性

设Rⁿ 是n-维欧氏空间n≥3.用Ω_n表示Rⁿ 上的单位球面,对于函数f∈L（Ω_n）,E_N^δ（f）表示其Fourier-Laplace级数的δ阶Cesaro平均所决定的等收敛算子,其中,λ:=（n-2）/2,δ是熟知的临界指标.对于0<δ≤λ,令p₀:=(2λ)/（λ+δ）,本文主要证明了如下结果:     

Banach空间中φ-半压缩型映象不动点的迭代逼近

设X为实一致光滑Banach空间,K为X的非空凸子集满足K+K?K.设T：K→K为有界φ-半压缩映象.设{v_n｝_n=0^∞,｛v_n｝_n=0^∞为K中的序列,{α_n｝_n=0^∞,{β_n｝_n=0^∞为[0,1]中的实数列满足(?)若｛Ty_{n相似文献}   

多复变整函数与其关于全导数的微分多项式*

本文证明如下定理: 设f为Cⁿ上的一个非常数整函数,L_D(f) = a_kD^kf +a_k?1D^k?1f +· · · + a₁Df + a₀f,其中a_j ∈ C, a_k ≠ 0, D_j f是f的j阶全导数(j=1,2, · · ·,k).若f与L_D(f)两个有穷的CM分担值, 则f=L_D(f).     

退化弱拟正则映射的正则性

本文考虑退化弱拟正则映射.利用Hodge分解、逆Holder不等式等工具,证明了其正则性结果:存在指数q₁=q₁（n,l,K）1,q_1loc(Ω,Rⁿ)，都有f∈W^1,l_loc(Ω,Rⁿ) ，即f为退化拟正则映射.     

关于Morse引理的推广

Morse Lemma是奇点理论中一个极为重要的结论。[1]的作者称其文中的定理1和定理2是Morse Lemma的推广。为此我们愿就[1]中的几个问题与[1]的作者商榷。     

RECENT PROGRESS ON SPHERICAL HARMONIC APPROXIMATION MADE BY BNU RESEARCH GROUP ——In memory of Professor Sun Yongsheng

As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years （2001-2005）. The main topics are： convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.     

On a class of self-similar processes with stationary increments in higher order Wiener chaoses

We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.     

A REPRESENTATION FORMULA RELATED TO SCHR(O)DINGER OPERATORS

Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.     

On a class of Riemann surfaces

It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.     

CONTENTS OF VOLUME 30

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Instructions for contributions

正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with     

Journal of Mathematical Research with Applications Guide for Authors

正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.     

Staircase transportation problems with superadditive rewards and cumulative capacities

A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].