An application for an implicit function theorem of Craven and Nashed: Continuum limits of lattice differential equations

We deal with the continuum limit of lattice differential equations and show how an implicit function theorem of Craven and Nashed can be used in order to continuate solutions of the resulting partial differential equation to solutions of the original spatially discrete system.     

α-型及其应用

本文以α型为基本工具研究代数问题，给出了Abian结果的一个进一步的结果，并给出了域上的无限线性方程组有解的一点判定准则。     

On the asymptotics of some systems of difference equations

We prove an inclusion theorem regarding a system of difference equations and apply it in getting the asymptotics of some solutions of some concrete difference equations.     

ODE Methods in Non-Local Equations

Non-local equations cannot be treated using classical ODE theorems. Nevertheless, several new methods have been introduced in the non-local gluing scheme of our previous article; we survey and improve those, and present new applications as well. First, from the explicit symbol of the conformal fractional Laplacian, a variation of constants formula is obtained for fractional Hardy operators. We thus develop, in addition to a suitable extension in the spirit of Caffarelli–Silvestre, an equivalent formulation as an infinite system of second order constant coefficient ODEs. Classical ODE quantities like the Hamiltonian and Wrońskian may then be utilized. As applications, we obtain a Frobenius theorem and establish new Pohožaev identities. We also give a detailed proof for the non-degeneracy of the fast-decay singular solution of the fractional Lane–Emden equation.     

A kinetic approach to comparison properties for degenerate parabolic-hyperbolic equations with boundary conditions

We study the comparison principle for degenerate parabolic-hyperbolic equations with initial and nonhomogeneous boundary conditions. We prove a comparison theorem for any entropy sub- and supersolution. The L¹ contractivity and, therefore, uniqueness of entropy solutions has been obtained so far by some authors, but it seems that any comparison theorem is not proven. The method used there is the doubling variable technique due to Kru?kov. Our method is based upon the kinetic formulation and the kinetic techniques. By developing the kinetic techniques for degenerate parabolic-hyperbolic equations with boundary conditions, we can obtain a comparison property which obviously extends the L¹ contractive property.     

A generalized existence theorem of backward doubly stochastic differential equations

In this paper, we deal with a class of one-dimensional backward doubly stochastic differential equations （BDSDEs）. We obtain a generalized comparison theorem and a generalized existence theorem of BDSDEs.     

Proof of the Absence of Elliptic Solutions of the Cubic Complex Ginzburg-Landau Equation

We consider the cubic complex Ginzburg-Landau equation. Using Hone's method, based on formal Laurent-series solutions and the residue theorem, we prove the absence of elliptic standing-wave solutions of this equation. This result complements a result by Hone, who proved the nonexistence of elliptic traveling-wave solutions. We show that it is more efficient to apply Hone's method to a system of polynomial differential equations rather than to an equivalent differential equation. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 146, No. 1, pp. 161–171, January, 2006.     

Reflected backward doubly stochastic differential equations with discontinuous coefficients

In this paper, we study one-dimensional reflected backward doubly stochastic differential equations (RBDSDEs) with one continuous barrier and discontinuous (left or right continuous) generator. We obtain an existence theorem and a comparison theorem for solutions of the class of RBDSDEs.     

A comparison theorem and uniqueness theorem of backward doubly stochastic differential equations

In this paper, we deal with one dimensional backward doubly stochastic differential equations (BDSDEs). We obtain a comparison theorem and a uniqueness theorem for BDSDEs with continuous coefficients.     

Optimal control of the bidomain system (I): The monodomain approximation with the Rogers-McCulloch model

For the monodomain approximation of the bidomain equations, a weak solution concept is proposed. We analyze it for the FitzHugh-Nagumo and the Rogers-McCulloch ionic models, obtaining existence and uniqueness theorems. Subsequently, we investigate optimal control problems subject to the monodomain equations. After proving the existence of global minimizers, the system of the first-order necessary optimality conditions is rigorously characterized. For the adjoint system, we prove an existence and regularity theorem as well.     

A Proof of the Uniformization Theorem on S2

We present a simple proof for the uniformization theorem on 2-sphere by methods of elliptic partial differential equations.     

Existence of weak solutions to the Keller–Segel chemotaxis system with additional cross-diffusion

In this paper, we consider the Keller–Segel chemotaxis system with additional cross-diffusion term in the second equation. This system is consisting of a fully nonlinear reaction–diffusion equations with additional cross-diffusion. We establish the existence of weak solutions to the considered system by using Schauder’s fixed point theorem, a priori energy estimates and the compactness results.     

A Generalization of a Theorem of Birch

We generalize a theorem of Birch on solving systems of homogeneous equations of odd degree to the case of solving systems of homogeneous equations of degree not divisible by a fixed integer s ≥ 2. Birch's theorem is the case s = 2. In addition, we give a new exposition of the proof of Brauer's theorem on solving systems of homogeneous equations.     

On an extension of Rolle's theorem to locally convex spaces

This work concerns the extension of a weak form of the Rolle's theorem to locally convex spaces that satisfy an axiom of separation. The result provides a condition for asserting the uniqueness of a solution to nonlinear functional equations, including nonlinear integro-differential equations. We use the extended Rolle's theorem to prove the uniqueness of a solution to a nonlinear, fractional differential equation.     

几个随机算子定理

得到Banach空间中随机隐函数存在定理、随机反函数定理和随机Hahn-Banach定理，它们是著名隐函数定理、反函数定理和Hahn-Banach控制延拓定理的随机化推广，这些定理在随机算子理论中将起重要作用。     

Nonlinear three-point third-order boundary value problems

In this paper we consider three-point boundary value problems for third-order differential equations. We provide simple sufficient conditions in order to obtain a priori bounds on solutions. We then rely on the topological transversality theorem of Granas or on Schaefer’s theorem to prove existence of solutions.     

矩阵秩分解定理的一个证明及其应用

矩阵的秩分解定理是矩阵论中的一个基础性定理.本文给出了秩分解定理的一个证明,描述了其中可逆矩阵P,Q的构造,讨论了秩分解定理及其P,Q的构造在解线性方程组中的应用,以及在判别Sylvester不等式等号成立中的应用.     

Implicit function theorem and its application to a Ulam’s problem for exact differential equations

We prove a global version of the implicit function theorem under a special condition and apply this result to the proof of a modified Hyers-Ulam-Rassias stability of exact differential equations of the form, g（x, y） ＋ h（x, y）y＇ =0.     

Wilson's theorem for consensus functions on hierarchies

Wilson in 1972 gave a generalization of Arrow's theorem without the Pareto axiom. We prove a version of Wilson's theorem for consensus functions on hierarchies.     

关于反射倒向随机微分方程的解的一些性质(英文)

研究了关于反射倒向随机微分方程的解的一些性质.同时在适当的条件下建立了关于反射倒向随机微分方程生成元的一个唯一性定理和一个逆比较定理.