On bounded solutions of a nonlinear Schrödinger equation on the half-line

We consider the problem on nonzero solutions of the Schrödinger equation on the half-line with potential that implicitly depends on the wave function via a nonlinear ordinary differential equation of the second order under zero boundary conditions for the wave function and the condition that the potential is zero at the beginning of the interval and its derivative is zero at infinity. The problem is reduced to the analysis and investigation of solutions of the Cauchy problem for a system of two nonlinear second-order ordinary differential equations with initial conditions depending on two parameters. We show that if the solution of the Cauchy problem for some parameter values can be extended to the entire half-line, then there exists a nonzero solution of the original problem with finitely many zeros.     

Multiple Unbounded Positive Solutions for Three-Point BVPs with Sign-Changing Nonlinearities on the Positive Half-Line

This work is concerned with the existence of unbounded positive solutions for a second-order nonlinear three-point boundary value problem on the positive half-line. The interesting points of the results are that the nonlinearity depends on the solution and its derivative and may change sign. Moreover, it satisfies general polynomial growth conditions. New existence results of nontrivial single and multiple positive solutions are proved using recent fixed point theorems on cones in a special Banach space.     

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.     

半直线上耦合系统边值问题三个正解的存在性

讨论了半直线上非线性耦合系统边值问题,应用Leggett-Williams不动点定理,得到了三个正解的存在性结果,推广并改进了现有结果.     

On the singular nonlinear self-adjoint eigenvalue problem for differential algebraic systems of equations

The general nonlinear self-adjoint eigenvalue problem for a differential algebraic system of equations on a half-line is examined. The boundary conditions are chosen so that the solution to this system is bounded at infinity. Under certain assumptions, the original problem can be reduced to a self-adjoint system of differential equations. After certain transformations, this system, combined with the boundary conditions, forms a nonlinear self-adjoint eigenvalue problem. Requirements for the appropriate boundary conditions are clarified. Under the additional assumption that the initial data are monotone functions of the spectral parameter, a method is proposed for calculating the number of eigenvalues of the original problem that lie on a prescribed interval of this parameter.     

一类半无穷区间奇异边值问题正解的存在性

在半无穷区间上讨论带有非齐次边界条件的奇异边值问题正解的存在性,多解性及不存在性．主要结果的证明基于上下解方法,Schauder不动点定理及拓扑度理论．     

半无穷区间上二阶三点边值问题的多个正解的存在性(英文)

In this paper,we are concerned with the existence of multiple positive solutions to a second-order three-point boundary value problem on the half-line.The results are obtained by the Leggett-Williams fixed point theorem.     

Existence of Three Positive Solutions of Three-Order with m-Point Impulsive Boundary Value Problems

By using fixed-point index theory and a new fixed-point theorem in cones, some sufficient conditions for the existence of countably many positive solutions for singular third-order boundary value problem on the half-line are established, which are the complement of previously known results. The interesting point lies in the fact that the nonlinear term is allowed to depend on the first order derivative u′.     

Initial boundary value problems for nonlinear dispersive wave equations

In this paper we study initial value boundary problems of two types of nonlinear dispersive wave equations on the half-line and on a finite interval subject to homogeneous Dirichlet boundary conditions. We first prove local well-posedness of the rod equation and of the b-equation for general initial data. Furthermore, we are able to specify conditions on the initial data which on the one hand guarantee global existence and on the other hand produce solutions with a finite life span. In the case of finite time singularities we are able to describe the precise blow-up scenario of breaking waves. Our approach is based on sharp extension results for functions on the half-line or on a finite interval and several symmetry preserving properties of the equations under discussion.     

Positive Solutions for Singular Third-Order Boundary Value Problem with Dependence on the First Order Derivative on the Half-Line

By using fixed-point index theory and a new fixed-point theorem in cones, some sufficient conditions for the existence of countably many positive solutions for singular third-order boundary value problem on the half-line are established, which are the complement of previously known results. The interesting point lies in the fact that the nonlinear term is allowed to depend on the first order derivative u′.     

Multiple positive solutions of n-point boundary value problems on the half-line in Banach spaces

In this paper, the fixed point index theory is used to investigate the existence of at least two positive solutions of n-point boundary value problem on the half-line in a Banach space. As an application, we give an example to demonstrate our results.     

Well-posedness of a problem with initial conditions for hyperbolic differential-difference equations with shifts in the time argument

We study a problem with initial conditions on the half-line for a differentialdifference equation of the hyperbolic type with deviations of the time argument. We obtain sufficient conditions for the well-posed solvability of the problem in Sobolev spaces with an exponential weight. In terms of the spectrum of the problem operator, we obtain necessary conditions for the well-posed solvability of the problem, sufficient conditions for the absence of solutions, and sufficient conditions for the nonuniqueness of the solution.     

Formulation and well-posedness of the Cauchy problem for a diffusion equation with discontinuous degenerating coefficients

The choice of a differential diffusion operator with discontinuous coefficients that corresponds to a finite flow velocity and a finite concentration is substantiated. For the equation with a uniformly elliptic operator and a nonzero diffusion coefficient, conditions are established for the existence and uniqueness of a solution to the corresponding Cauchy problem. For the diffusion equation with degeneration on a half-line, it is proved that the Cauchy problem with an arbitrary initial condition has a unique solution if and only if there is no flux from the degeneration domain to the ellipticity domain of the operator. Under this condition, a sequence of solutions to regularized problems is proved to converge uniformly to the solution of the degenerate problem in L ₁(R) on each interval.     

Existence and iteration of positive solutions for high-order fractional differential equations with integral conditions on a half-line

In this paper, existence and iteration of positive solutions for a class of high-order fractional differential equations with integral conditions on a half-line is investigated. By means of a monotone iterative technique, we obtain not only the existence of positive solutions for the problems, but also establish iterative schemes for approximating the solutions.     

Stationary Solutions of the KdV Equation

In this article, as a first step to study the large time behavior of solutions to the KdV equation on a half-line, we prove the existence of the stationary solutions to the corresponding problem. The aim is to concentrate on understanding the influence of boundary conditions.     

An inverse problem for Sturm-Liouville operators on the half-line having Bessel-type singularity in an interior point

We study the inverse problem of recovering Sturm-Liouville operators on the half-line with a Bessel-type singularity inside the interval from the given Weyl function. The corresponding uniqueness theorem is proved, a constructive procedure for the solution of the inverse problem is provided, also necessary and sufficient conditions for the solvability of the inverse problem are obtained.     

Positive Solution of Singular Boundary Value Problems on a Half-Line

This paper investigates existence of positive solutions of singular sub-linear boundary value problems on a half-line. Necessary and sufficient conditions for the existence of positive continuous solutions or smooth solutions on [0, ∞] are given by constructing new lower and upper solutions.     

Positive Solutions to Second Order Singular Differential Equations Involving the One-Dimensional M-Laplace Operator

We consider a class of second order quasilinear differential equations with singular ninlinearities. Our main purpose is to investigate in detail the asymptotic behavior of their solutions defined on a positive half-line. The set of all possible positive solutions is classified into five types according to their asymptotic behavior near infinity, and sharp conditions are established for the existence of solutions belonging to each of the classified types.     

Positive solutions to a class of second order differential equations with singular nonlinearities

A class of second order quasilinear differential equations with singular nonlinearities is considered. The set of all possible solutions defined on a positive half-line [a,∞) is classified into six types according to their aymptotic behavior as t→∞, and sharp conditions are established for the existence of solutions belonging to each of the classified types.     

Multiple Positive Solutions for a Coupled System of Nonlinear Fractional Differential Equations on the Half-line

In this paper, we study a boundary value problem for a coupled differential system of fractional order on the half-line. The differential operator is taken in the Riemann–Liouville sense and the nonlinear terms involve the fractional derivative of the unknown functions. Applying the Schäuder fixed point theorem, we prove the existence of infinitely many positive unbounded solutions of the fractional differential system. Also, we give examples to illustrate our main result.