Positive Solutions of Fully Nonlinear Elliptic Equations on General Bounded Domains

We prove the refined ABP maximum principle, comparison principle, and related existence and uniqueness theorem for the positive solutions of the Dirichlet problems of second order fully nonlinear elliptic equations on arbitrary bounded domains.     

Bounded Nonoscillatory Solutions of Nonlinear Functional Differential Equations

In this paper, we obtain some nonoscillatory theories of the functional differential equation （r（t）ψ（x（t））x （t）） ＋ f（t, x（t）, x（σ（t））） = 0, t ≥ t 0 , where r ∈ C 1 （[t 0 , ∞）; （0, ∞））, ψ∈ C 1 （R, R） and f ∈ C（[t 0 , ∞） × R × R, R）.     

On Bounded Solutions for Nonlinear Parabolic Equations with Degenerate Coercivity

Mediterranean Journal of Mathematics - By means of Stampacchia’s lemma, we prove an existence result of bounded solutions for some nonlinear parabolic equations with degenerate coercivity.     

Bounded Positive Solutions of Schrödinger Equations in Two-Dimensional Exterior Domains

We prove under quite general assumptions the existence of a bounded positive solution to the semilinear Schrödinger equation in a two-dimensional exterior domain.     

Bounded Solutions of Some Second Order Nonlinear Differential Equations

We prove Landesman–Lazer type existence conditions forthe solutions bounded on the real line, together with theirfirst derivatives, for some second order nonlinear differentialequations of the form x'+cx'+f(t, x)=0. The proofs use upperand lower solutions techniques together with some limiting arguments.     

一类时滞非线性伪抛物型方程的有界解

本文讨论了一类时滞非线性伪抛物型方程Cauchy问题有界解的存在唯一性问题 ,给出了有界解存在唯一的充分条件 .     

有界时滞非线性随机微分方程解的振动性和非振性

研究了一类非线性随机时滞微分方程解的振动性和非振性,其中设定时滞可变且有界.依据该方程漂移项和扩散项的性质,证明了通过选定适当的初值,方程依概率存在正解;同时,给出了方程解几乎必然振动的一个充分条件.     

一般有界区域上次线性椭圆方程改进的正解估计

在一般有界区域上，建立了次线性椭圆方程广义Ｄｉｒｉｃｈｌｅｔ问题改进的正解估计和有界强解的存在性定理．     

Positive Solutions of Nonlinear Elliptic Equations in Unbounded Domains in R 2

We study the existence of positive solutions of the nonlinear equation u+f(,u)=0, in D with u=0 on D, where D is an unbounded domain in R ² with a compact nonempty boundary D consisting of finitely many Jordan curves. The aim is to prove an existence result for the above equation in a general setting by using potential theory.     

球外部区域上非线性椭圆型方程的正径向解

本文讨论球外部区域Ω={x∈RN||x|>R}上非线性椭圆边值问题正径向解的存在性,其中g(r),f(u)为非负连续函数.在g(r)满足条件0<∫R∞rg(r)dr<∞,f(u)关于u超线性或次线性增长的情形,获得了该问题正径向解的存在性.     

GLOBAL EXISTENCE OF THE SOLUTIONS TO NONLINEAR HYPERBOLIC EQUATIONS IN EXTERIOR DOMAINS

This paper deals with the following IBV problem of nonlinear hyperbolic equations u_(tt)- sum from i, j=1 to n a_(jj)(u, Du)u_(x_ix_j)=b(u, Du), t>0, x∈Ω, u(O, x) =u~0(x), u_t(O, x) =u~1(v), x∈Ω, u(t, x)=O t>O, x∈()Ω,where Ωis the exterior domain of a compact set in R~n, and |a_(ij)(y)-δ_(ij)|= O(|y|~k), |b(y)|=O(|y|~(k+1)), near y=O. It is proved that under suitable assumptions on the smoothness,compatibility conditions and the shape of Ω, the above problem has a unique global smoothsolution for small initial data, in the case that k=1 add n≥7 or that k=2 and n≥4.Moreover, the solution ham some decay properties as t→ + ∞.     

Alternating Sign Multibump Solutions of Nonlinear Elliptic Equations in Expanding Tubular Domains

Let Γ denote a smooth simple curve in ? ^N , N ≥ 2, possibly with boundary. Let Ω _R be the open normal tubular neighborhood of radius 1 of the expanded curve RΓ: = {Rx | x ∈ Γ??Γ}. Consider the superlinear problem ? Δu + λu = f(u) on the domains Ω _R , as R → ∞, with homogeneous Dirichlet boundary condition. We prove the existence of multibump solutions with bumps lined up along RΓ with alternating signs. The function f is superlinear at 0 and at ∞, but it is not assumed to be odd. If the boundary of the curve is nonempty our results give examples of contractible domains in which the problem has multiple sign changing solutions.     

一些非线性发展方程的有界钟状代数孤立波解

本文以非线性发展方程的有界钟状代数孤波解为研究对象,以Kolmogorov-Petrovskii-Piskunov(简称KPP)方程、组合KdV-mKdV方程和mKdV方程为例,利用平面动力系统知识,分析有界钟状代数孤立波解出现的条件,提出求解的方法,称之为代数孤波解解法(简称ASW解法),分别获得这三个方程的代数孤立波解.     

Nonlinear Integroparabolic Equations on Unbounded Domains: Existence of Classical Solutions with Special Properties

Classical solvability is established for a certain nonlinear integrodifferential parabolic equation, on unbounded domains in several dimensions. The model equation of the Fokker-Planck type represents a regularized version of an equation recently derived by J. A. Acebrón and R. Spigler for the physical problem of describing the time evolution of large populations of nonlinearly globally coupled random oscillators. Precise estimates are obtained for the decay of convolutions with fundamental solutions of linear parabolic equations on unbounded domains in R ⁿ . Existence of a classical solution with special properties is established.     

Global Weak Solutions for SQG in Bounded Domains

We prove existence of global weak L² solutions of the inviscid SQG equation in bounded domains. © 2017 Wiley Periodicals, Inc.     

Attractors for Damped Quintic Wave Equations in Bounded Domains

The dissipative wave equation with a critical quintic non-linearity in smooth bounded three-dimensional domain is considered. Based on the recent extension of the Strichartz estimates to the case of bounded domains, the existence of a compact global attractor for the solution semigroup of this equation is established. Moreover, the smoothness of the obtained attractor is also shown.