Fundamental Solutions of Some Linear Operator Equations and Applications

A concept of a fundamental solution is introduced for linear operator equations given in some functional spaces. In the case where this fundamental solution does not exist, the representation of the solution is found by the concept of a generalized fundamental solution, which is introduced for operators with nontrivial and generally infinite-dimensional kernels. The fundamental and generalized fundamental solutions are also investigated for a class of Fredholm-type operator equations. Some applications are given for one-dimensional generally nonlocal hyperbolic problems with trivial, finite- and infinite-dimensional kernels. The fundamental and generalized fundamental solutions of such problems are constructed as particular solutions of a system of integral equations or an integral equation. These fundamental solutions become meaningful in a general case when the coefficients are generally nonsmooth functions satisfying only some conditions such as p-integrablity and boundedness.     

Some Applications of the Regularity and Irreducibility on Transport Theory

This paper is concerned with the spectral analysis of transport operator with general boundary conditions in L ₁-setting. This problem will be investigated under results from the theory of positive linear operators, irreducibility and regularity of the collision operator. The basic problems treated here are notions of essential spectra, spectral bound and leading eigenvalues.     

A Note on the Regularity of Solutions to a Nonlinear Elliptic System from Elasticity-Plasticity Theory

The regularity of the weak solutions to an elliptic system from elasticity-plasticity theory is studied. Although this system is a nonlinear elliptic system with discontinuous coefficients, C^{1,\alpha}-everywhere regularity for its weak solutions is proved.     

亚纯函数理论的一个基本不等式及其应用

本文首先证明了关于亚纯函数理论的一个基本不等式,进而用此不等式研究了与Hayman的一个结果密切相关的一类亚纯函数的值分布问题,得到如下结果:如果 f是一个超越亚纯函数,其所有零点的重数至少为k,则函数ff(k)取每一个有穷非零复数无穷多次,至多除去三个可能的例外正整数k=2,3,4．     

Solvability Theory and Projection Methods for a Class of Singular Variational Inequalities: Elastostatic Unilateral Contact Applications

The mathematical modeling of engineering structures containing members capable of transmitting only certain type of stresses or subjected to noninterpenetration conditions along their boundaries leads generally to variational inequalities of the form , where C is a closed convex set of (kinematically admissible set), (loading strain vector), and (stiffness matrix). If rigid body displacements and rotations cannot be excluded from these applications, then the resulting matrix M is singular and serious mathematical difficulties occur. The aim of this paper is to discuss the existence and the numerical computation of the solutions of problem (P) for the class of cocoercive matrices. Our theoretical results are applied to two concrete engineering problems: the unilateral cantilever problem and the elastic stamp problem.     

Regularity of Radial Solutions to the Complex Hessian Equations

In this paper we consider regularities of radial solutions to the degenerate complex Hessian equations. Our results generalize some results for Monge-Ampere equation in [Monn, Math. Ana. 275 （1986）, pp. 501-511] and [Delanoe, J. Diff. Eqn. 58 （1985）, pp. 318-344].     

Regularity Criteria of the Solutions to Axisymmetric Magnetohydrodynamic System

In this paper, we consider Cauchy problem of the axially symmetric Magnetohydrodynamic (MHD) system. By using energy method, we establish some regularity criteria of the solutions for the axisymmetric solutions of the three dimensional incompressible MHD system.     

Subspace Interpolation with Applications to Elliptic Regularity

In this paper, we prove new embedding results by means of subspace interpolation theory and apply them to establishing regularity estimates for the biharmonic Dirichlet problem and for the Stokes and the Navier–Stokes systems on polygonal domains. The main result of the paper gives a stability estimate for the biharmonic problem at the threshold index of smoothness. The classic regularity estimates for the biharmonic problem are deduced as a simple corollary of the main result. The subspace interpolation tools and techniques presented in this paper can be applied to establishing sharp regularity estimates for other elliptic boundary value problems on polygonal domains.     

Regularity of Stationary Weak Solutions in the Theory of Generalized Newtonian Fluids with Energy Transfer

In this paper, we prove regularity results for weak solutions to some stationary problems arising in the theory of generalized Newtonian fluids with energy transfer. Namely, we prove that these solutions are strong. In the two-dimensional case, we prove the Hölder continuity of the first gradient of a solution. Bibliography: 30 titles.     

Index Iteration Theory for Brake Orbit Type Solutions and Applications

In this paper, we give a survey on the index iteration theory of an index theory for brake orbit type solutions and its applications in the study of brake orbit problems including the Seifert conjecture and the minimal period solution problems in brake orbit cases.     

Regularity of Solutions to Bilinear Stochastic Wave Equations

Abstract

The paper is concerned with strong solutions of bilinear stochastic wave equations in ? ^d , of which the coefficients contain semimartingale white noises with spatial parameters. For the Cauchy problems, the existence and spatial regularity of solutions in Sobolev spaces are proved under appropriate conditions. The dependence of solution regularity on the smoothness of the random coefficients is ascertained. The proofs are based on stochastic energy inequalities, the semigroup method and certain submartingale inequalities. Regularity results are also obtained for the special case of Wiener semimartingales.     

一类退缩椭园型方程弱解的正则性

本文得出一类形如：－Ｄｉｖ（ｇ（｜Ｄｕ｜）｜Ｄｕ｜＾ｐ－２Ｄｕ＋ｆ（ｘ,ｕ））＝Ｂ（ｘ,ｕ,Ｄｕ）在一定的条件下在Ｗ＾１．ｐ空间中的弱解的Ｈｏｌｄｅｒ连续性。     

Dirichlet Problems in Polyhedral Domains I: Regularity of the Solutions

The solution of the Dirichlet problem relative to an elliptic operator in a polyhedron has a complex singular behaviour near edges and vertices. Here we show that this solution and its conormal derivative have a global regularity in appropriate weighted Sobolev spaces. We also investigate some compact embeddings of these spaces. The present results will be applied in a forthcoming work to the constructive treatment of the problem by optimal convergent finite clement method and boundary element method.     

Eventual Regularity of the Solutions to the Supercritical Dissipative Quasi-Geostrophic Equation

We show that a solution to the supercritical surface quasi-geostrophic equation that is smooth up to a certain time must remain smooth forever.     

关于Hamilton-Jacobi方程解的正则性和全局结构的注记

该文考虑高维Hamilton-Jacobi方程的柯西问题.作者证明了从任一初始点出发的特征线永不碰到奇异点集合的充分必要条件是初始函数在该点取到最小值.在此基础上,证明了奇异点集合的道路连通分支和初始函数不取最小值的点集合的道路连通分支之间存在一一对应,而且解的梯度的间断一旦产生就不会消失.特别指出,该文的结果不需要初始函数梯度在无穷远趋近于零这一限制条件,而文献[12]中重要的命题2.7和主要结果之一的定理3.3是在这一条件下得到的.     

Morrey Regularity of Solutions to Degenerate Elliptic Equations in Rn

In this paper, we study the Morrey regularity of solutions to the de- generate elliptic equation -(a_{ij}u_{xi})_{xj} = -(f_j)_{xj} in R^n. For this purpose, we introduce four weighted Morrey spaces in R^n.     

Regularity and Morse Index of the Solutions to Critical Quasilinear Elliptic Systems

Regularity results and critical group estimates are studied for critical (p, r)-systems. Multiplicity results of solutions for a critical potential quasilinear system are also proved using Morse theory.     

Regularity of Solutions to Elliptic Equations with VMO Coefficients

The aim of this paper is to study the regularity of solutions to the Dirichlet problems for general second-order elliptic equations in Lebesgue and Morrey spaces. We consider both nondivergence and divergence forms and the coefficients of principle terms are assumed to be in VMO.