一类四阶非线性椭圆问题变号解的存在性

通过建立一个新空间,在新空间中讨论了一个含Hardy位势的四阶非线性椭圆问题变号解的存在性.在一个环绕定理下,得到了问题变号解的存在性.     

分数阶p(x)-Laplace算子方程的多解性

本文研究了一类分数阶p(x)-Laplace算子方程解的存在性和多解性问题.在非线性项不满足(AR)条件时,利用喷泉定理和分数阶变指数Sobolev空间的相关理论,得到了方程无穷多解的存在性.从而推广了经典变指数问题的相关结果.     

Banach空间中混合型积分-微分方程解的存在性

将微分方程初值问题转化为等价的积分方程,近来此方法被应用于讨论非线性微分方程初值问题解的存在性.利用凸幂凝聚算子的不动点定理,研究了Banach空间中混合型非线性二阶积分-微分方程的初值问题解的存在性.     

一类混合单调算子方程的求解及应用

利用锥理论和半序方法证明了Banach空间中一类非线性二元算子方程的解的存在唯一性定理,并给出迭代序列收敛于解的误差估计,作为应用,讨论了不具有单调性的算子方程的可解性,改进并推广了已有的一些结果.     

一致椭圆型算子边值问题变号解的存在性

利用Banach空间锥理论、算子的指数理论、上下解理论研究了含有一致椭圆型算子的椭圆边值问题变号解的存在性,同时分别得到了一个正解和一个负解.特别当非线性项是奇函数时,该边值问题至少存在一个正解,一个负解和两个变号解.     

非线性分数阶微分方程三点边值问题解的存在性

讨论了一类非线性分数阶微分方程三点边值问题解的存在性.微分算子是Riemann-Liouville导算子并且非线性项依赖于低阶分数阶导数.通过将所考虑的问题转化为等价的Fredholm型积分方程,利用Schauder不动点定理获得该三点边值问题至少存在一个解.     

非线性电报方程组的3个双周期正解问题

主要考虑了带有双周期边值条件的耦合的非线性电报方程组的至少有3个双周期正解的存在性.首先利用线性电报方程的Green函数和极值原理,将非线性电报方程组解的存在性转化为算子的不动点.其次赋予非线性项一定的增长条件,然后利用有序Bamach空间锥上的Leggett-Williams不动点定理来证明算子在锥中至少存在3个不动点,即非线性电报方程组至少3个非负双周期解的存在性.     

跳跃非线性条件下椭圆边值问题的变号解和多解存在性

本文应用Banach空间常微分方程和极大极小理论,特别是相对山路引理研究了零点和无穷远点跳跃非线性条件下椭圆边值问题的变号解和多解,得到新的变号解和多解存在性定理,最后我们得到6个非平凡解的存在性.     

一类Curvature方程的两种边值问题解的存在性

利用含有伪单调算子的变分不等式解的存在性定理,证明一类具有Dirichlet边值条件的Curvature方程在W1,p(Ω)空间中存在唯一解.深入研究具有Dirichlet边值条件的Curvature方程和具有Neumann边值条件的Curvature方程之间的关系,利用极大单调算子值域的扰动理论,给出具有Neumann边值条件的Curvature方程在W1,p(Ω)空间中存在解的充分条件.文中采用一些新的证明技巧,推广和补充了以往的相关研究成果.     

对广义强非线性拟变分包含带有误差的近似点算法

本文研究了一类广义强非线性拟变分包含.在Hilbert空间内利用与极大单调映象相联系的预解算子的性质,对广义强非线性拟变分包含建立了解的存在性定理和建议了一个新的寻求近似解的带有误差的近似总算法,证明了近似解序列强收敛于精确解.作为特例,在此领域内的某些已知结果也被讨论.     

Existence of positive solutions for Sturm-Liouville boundary value problems on the half-line

In this paper, we establish sufficient conditions to guarantee the existence of at least one positive solution, a unique positive solution, and multiple positive solutions for the Sturm-Liouville boundary value problem on the half-line. By using an effective operator, the fixed point theorems in cone, especially Krasnoselskii fixed point theorem, can be applied to such systems and then existence criteria are established. The interesting point of the results is that the nonlinear term f can be sign-changing.     

Mountain pass theorem in ordered Banach spaces and its applications to semilinear elliptic equations

In this paper, we establish a mountain pass theorem in an ordered Banach space, which is a Riesz-Banach space such that the absolute value is continuous. Applying our theorem to semilinear elliptic equations with sign-changing nonlinear terms, we prove the existence of a positive solution.     

非线性算子方程的变号解及其应用

利用锥理论讨论了非线性算子方程变号解的存在性,所得结果在理论上推广了相关文献的结论. 作为应用,考虑了二阶三点边值问题, 得到了新的结论.     

Existence of positive solutions for a system of semipositone coupled discrete boundary value problems

We study the existence of positive solutions for a system of nonlinear second-order difference equations with parameters and sign-changing nonlinearities, subject to multi-point coupled boundary conditions. In the proof of our main theorems we use the nonlinear alternative of Leray-Schauder type and the Guo-Krasnosel'skii fixed point theorem.     

New Linking Theorem and Sign-Changing Solutions

Abstract

In this paper, we study the existence of sign-changing solutions for nonlinear elliptic equations via linking methods. A general liking type theorem is given with the location of the critical point produced specified in terms of the cone structure of the space. The abstract theorem is applied to elliptic equations that have jumping nonlinearities, and may or may not be resonant with respect to Fu?ík spectrum.     

空间非线性四阶奇异积分边值问题正解的存在性

通过构造一个特殊的非空凸闭集,利用M\"onch 不动点定理在有关相应线性算子的第一特征值的条件下, 得到了Banach空间中具有积分边值条件的四阶奇异微分方程正解的存在性.     

Successively iterative method of nonlinear Neumann boundary value problems

Two successively iterative sequences are constructed for computing solutions of the nonlinear Neumann boundary value problems with time singularity. The sequences start off with some constants. Main tool is the fixed point theorem of increasing operator on the order interval. By considering convergence of the sequences, we prove the existence of nontrivial sign-changing solutions.     

非线性算子方程变号解的存在性及其应用

本文利用锥理论讨论了非线性算子方程变号解的存在性,并将抽象结果应用于Sturm-Liouville两点边值问题。所得结果无论在理论上还是在应用上都是新的.     

A twist condition and multiple solutions of unbounded self-adjoint operator equation with symmetries

By using the index theory for unbounded self-adjoint operator equations and the symmetric mountain pass theorem, we investigate the existence of multiple solutions for nonlinear operator equations with twist conditions. We prove an abstract theorem, and give some applications to first order Hamiltonian systems with Sturm–Liouville boundary conditions and delay differential equations.