Classification of Isometric Immersions of the Hyperbolic Space H 2 into H 3

We transform the problem of determining isometric immersions from H ²(-1) into H ³(c) (c of solving an elliptic Monge--Ampère equation on the unit disc. Then we classify isometric immersions which possess bounded principal curvatures.     

A Cylinder Theorem for Isometric Pluriharmonic Immersions

We prove a cylinder theorem for isometric pluriharmonic immersions of complete Kähler manifolds into semi-Euclidean spaces under an assumption concerning the index of relative nullity.     

紧黎曼对称空间到Grassmann流形的等变等距极小浸入

在本文中，我们利用李群及其表示理论作为主要工具，　讨论了紧黎曼对称空间到Ｇｒａｓｓｍａｎｎ　流形的等变等距极小浸入问题．     

不定度量空间型到不定度量空间型的等距浸入和孤立子理论

我们利用孤立子理论得到了构造有相同指标的不定度量空间型到不定度量空间型的等距浸入的方法．     

Radial Graphs with Constant Mean Curvature in the Hyperbolic Space

The existence is proved of radial graphs with constant mean curvature in the hyperbolic space H ⁿ⁺¹ defined over domains in geodesic spheres of H ⁿ⁺¹ whose boundary has positive mean curvature with respect to the inward orientation.     

A Nonlocal Problem with Integral Conditions for the Quasilinear Hyperbolic Equation

In this paper, we consider a nonlocal problem with integral conditions for the quasilinear hyperbolic equation in a rectangular domain. The existence and uniqueness of the generalized solution are established.     

Microlocal Analysis and Global Solutions of Some Hyperbolic Equations with Discontinuous Coefficients

We are concerned with analyzing hyperbolic equations with distributional coefficients. We focus on the case of coefficients with jump discontinuities considered earlier by Hurd and Sattinger in their proof of the breakdown of global distributional solutions. Within the framework of Colombeau generalized functions, however, Oberguggenberger showed the existence and uniqueness of a global solution. Within this framework we develop further a microlocal analysis to understand the propagation of singularities of such Colombeau solutions. To achieve this we introduce a refined notion of a wave-front set, extending Hörmander's definition for distributions. We show how the coefficient singularities modify the classical relation of the wave front set of the solution and the characteristic set of the operator, with a generalized notion of characteristic set.     

A Rank Theorem of Operators between Banach Spaces

Suppose that E and F are two Banach spaces and that B(E, F) is the space of all bounded linear operators from E to F. Let T ₀∈B(E, F) with a generalized inverse T ₀ ⁺∈B(F, E). This paper shows that, for every T∈B(E, F) with ‖T ₀ ⁺ (T−T ₀)‖<1, B ≡ (I + T ₀ ⁺(T−T ₀))⁻¹ T ₀ ⁺ is a generalized inverse of T if and only if (I−T ₀ ⁺ T ₀)N(T) = N(T ₀), where N(·) stands for the null space of the operator inside the parenthesis. This result improves a useful theorem of Nashed and Cheng and further shows that a lemma given by Nashed and Cheng is valid in the case where T ₀ is a semi-Fredholm operator but not in general.     

包含$l^{\beta}(0<\beta<1)$渐近等距翻版的有界线性算子空间

Assume X is a normed space,every x ＊ ∈ S（X＊） can reach its norm at some point in B（X）,and Y is a β-normed space.If there is a quotient space of Y which is asymptotically isometric to l β,then L（X,Y） contains an asymptotically isometric copy of l β.Some sufficient conditions are given under which L（X,Y） fails to have the fixed point property for nonexpansive mappings on closed bounded β-convex subsets of L（X,Y）.     

带脉冲和时滞影响的非线性双曲型方程振动性的新准则

考虑一类具非线性扩散项的脉冲时滞双曲型偏微分方程的振动性,借助一阶脉冲时滞微分不等式,获得了该类方程在Dirichlet边值条件下所有解振动的若干充分判据.     

关于仿射线性相关性的探讨

在线性空间中引入了仿射线性相关的概念,给出了它的特征刻画及若干重要性质,并用仿射线性相关性刻画了非齐线性方程组解的结构。     

On the Complex of Sobolev Spaces Associated with an Abstract Hilbert Complex

We consider the complexes of Hilbert spaces whose differentials are closed densely-defined operators. A peculiarity of these complexes is that from their differentials we can construct Laplace operators in every dimension. The Laplace operator together with a sufficiently nice measurable function enables us to define a generalized Sobolev space. There exist pairs of measurable functions allowing us to construct some canonical mappings of the corresponding Sobolev spaces. We find necessary and sufficient conditions for those mappings to be compact. In some cases for a given Hilbert complex we can construct an associated Sobolev complex. We show that the differentials of the original complex are normally solvable simultaneously with the differentials of the associated complex and that the reduced cohomologies of these complexes coincide.     

On the Equivalence of Spectra of Linear Partial Differential Operators in Certain Function Spaces

For linear differential operators with coefficients of class C on ⁿ, we prove theorems on the simultaneous invertibility and equivalence of spectra in the Lebesgue space L ^p, Stepanov space M ^p, and in a particular Banach space V ^p L ^p, p 1     

A Survey on Explicit Representation Formulae for Fundamental Solutions of Linear Partial Differential Operators

In the present article, we aim at treating the existence of fundamental solutions of linear partial differential operators with constant coefficients from the viewpoint of setting up explicit formulae yielding fundamental solutions.     

A complete classification of parallel surfaces in three-dimensional homogeneous spaces

We complete the classification of surfaces with parallel second fundamental form in all three-dimensional homogeneous spaces. The second named author is a postdoctoral researcher of the Research Foundation—Flanders (FWO).     

基于Frobenius定理的Hamilton-Jacobi方法的几何解释

给出了一阶偏微分方程特征微分方程组的一种基于Frobenius定理的几何解释,通过研究发现根据Frobenius定理可以从一阶偏微分方程直接得到其特征微分方程组;在此基础上说明如何利用几何方法从Hamilton正则方程出发找到与之对应的Hamilton-Jacobi方程.这种方法可以被用于非保守或非完整Hamilton力学问题的研究中,经典Hamilton-Jacobi方法是这种方法的一个特例.     

An Inverse Function Theorem for Fréchet Spaces Satisfying a Smoothing Property and (DN)

Classical inverse function theorems of Nash-Moser type are proved for Fréchet spaces that admit smoothing operators as introduced by Nash. In this note an inverse function theorem is proved for Fréchet spaces which only have to satisfy the condition (DN) of Vogt and the smoothing property (S_Ω)_t; for instance, any Fréchet-Hilbert space which is an (Ω)-space in standard form has property (S_Ω)_t. The main result of this paper generalizes a theorem of Lojasiewicz and Zehnder. It can be applied to the space C^∞(K) if the compact K ? ?^N is the closure of its interior and subanalytic; different from classical results the boundary of K may have singularities like cusps. The growth assumptions on the mappings are formulated in terms of the weighted multiseminorms [ ]m,k introduced in this paper; nonlinear smooth partial differential operators on C^∞(K) and their derivatives satisfy these formal assumptions.     

关于Banach空间中度量广义逆扰动定理的注记

Banach空间中线性算子的度量广义逆扰动定理具有重要应用,引入关注.在Acta Math Sinica English Series,2014(7)中对于从Banach空间X到Banach空间Y的有界线性算子T,在T的值域R(T)为切比雪夫子空间,T的零空间N(T)为切比雪夫子空间,且度量投影π_(N(T))为线性的条件下,得到二个有关非线性的广义逆扰动定理.本文证得:上述扰动定理结论的条件无需假定π_(N(T))的线性,只需假定N(T),R(T)分别为X,Y中的切比雪夫子空间即可.     

$AL_P(\mu,H)$空间中单位球面间1-Lipschitz和反1-Lipschitz映射的线性等距延拓的一个注记

In this paper, we show that if V0 is a 1-Lipschitz mapping between unit spheres of LP (μ, H) and LP(ν,H)(p>2, H is a Hilbert space), and-V0(S(Lp(μ, H )))V0(S(Lp(μ, H))), then V0 can be extended to a linear isometry defined on the whole space. If 1相似文献   

A new method of solving the coefficient inverse problem

This paper is concerned with the new method for solving the coefficient inverse problem in the reproducing kernel space. It is different from the previous studies. This method gives accurate results and shows that it is valid by the numerical example.