On the basis property of eigenfunctions of a singular second-order differential operator

We consider the first boundary value problem for a singular differential operator of second order on an interval with transmission conditions at an interior point of the interval. We show that the system of eigenfunctions corresponding to this problem is complete in the space L ²(0, 1) and forms a Riesz basis in that space.     

A Twofold Spline Chebyshev Linearization Approach for a Class of Singular Second-Order Nonlinear Differential Equations

The aim of this paper is to present a twofold approach for the numerical solution of a class of singular second-order nonlinear differential equations. The first is based on a modified version of an adaptive spline collocation method (ASCM). The second is a patching approach (PASCM) that splits the problem domain into two subintervals: Chebyshev economization procedure is implemented in the vicinity of the singular point and outside this domain the resulting initial or boundary value problem is handled by the (ASCM). The second strategy is based on the linearization of the nonlinear term about the given initial condition at the singular point. The choice of either technique relies on the specified boundary or initial conditions. Performance of the approach is investigated numerically through a number of application examples that demonstrate the efficiency of the approach and that it has O(h ⁴) rate of convergence. Results confirm that the scheme yields highly accurate results when compared with the exact and/or numerical solutions that exist in the literature.     

Existence of positive solutions to n-point nonhomogeneous boundary value problem

In this paper, we are concerned with the existence of positive solutions to a n-point nonhomogeneous boundary value problem. By using the Krasnoselskii's fixed point theorem in Banach spaces, some sufficient conditions guaranteeing the existence of positive solution is established for the n-point nonhomogeneous boundary value problem.     

Banach空间中一类奇异脉冲积-微分混合方程边值问题多个正解的存在性

利用锥拉伸及锥压缩不动点定理,讨论了Banach空间中一类带奇异性的脉冲积-微分混合方程边值问题多个正解的存在性.     

Multiple positive solutions of a boundary value problem for a class of 2nth-order m-point singular integro-differential equations in Banach spaces

In this paper, we obtain the existence of multiple positive solutions of a boundary value problem for 2nth-order singular nonlinear integro-differential equations in a Banach space by means of fixed point index theory of completely continuous operators.     

Fixed-sign solutions for a system of singular focal boundary value problems

We consider a system of focal boundary value problems where the nonlinearities may be singular in the independent variable and may also be singular in the dependent arguments. Using Schauder fixed point theorem, we establish criteria such that the system of boundary value problems has at least one fixed-sign solution.     

Existence results for boundary value problems of high order differential equations involving Caputo derivative

We study boundary value problems for differential equations involving Caputo derivative of order ????(n?1,n) in Banach spaces. Existence and uniqueness results of solutions are established by virtue of the H?lder??s inequality, a suitable singular Gronwall??s inequality and fixed point theorem via a priori estimate method. At last, three examples are given to illustrate the results.     

Existence of multiple positive solutions for nth-order p-Laplacian m-point singular boundary value problems

In this paper, by using fixed point theorem, we prove the existence of multiple positive solutions for a class of nth-order p-Laplacian m-point singular boundary value problem. The interesting point is that the nonlinear term f explicitly involves the each-order derivative of variable u(t).     

Existence and uniqueness results for boundary value problems of higher order fractional integro-differential equations involving gronwall's inequality in banach spaces

We study boundary value problems for fractional integro-differential equations involving Caputo derivative of order α ∈ (n-1,n) in Banach spaces. Existence and uniqueness results of solutions are established by virtue of the Holder's inequality, a suitable singular Gronwall's inequality and fixed point theorem via a priori estimate method. At last, examples are given to illustrate the results.     

Problem with lacking Tricomi condition on a characteristic and an analog of the Frankl condition on a segment of the degeneration line for a class of mixed type equations

For the Gellerstedt equation with a singular coefficient, we consider a boundary value problem that differs from the Tricomi problem in that the boundary characteristic AC is arbitrarily divided into two parts AC ₀ and C ₀ C and the Tricomi condition is posed on the first of them, while the second part C ₀ C is free of boundary conditions. The lacking Tricomi condition is equivalently replaced by an analog of the Frankl condition on a segment of the degeneration line. The well-posedness of this problem is proved.     

Singular multipoint impulsive boundary value problem with p-Laplacian operator

In this paper, we obtain the existence of multiple positive solutions for a class of multipoint impulsive boundary value problem with p-Laplacian operator, where the nonlinearity may be singular on t=0, 1 and u=0. The main tool is the classical fixed point index theorem for compact maps.     

A study of a general system of operator equations in $${\varvec{}}$$-metric spaces via the vector approach in fixed point theory

In this paper, we will present some coupled fixed point theorems on a metric space endowed with two b-metrics. The approach is based on the application of a fixed point theorem for an appropriate operator on the Cartesian product of the given spaces. An application to a boundary value problem for a system of second order differential equations is also presented.     

一类具$p$-Laplace非线性三点边值问题三个正解的存在性

This paper deals with the existence of three positive solutions for a class of nonlinear singular three-point boundary value problem with p-Laplacian. By means of a fixed point theorem duo to Leggett and Williams, sufficient condition for the existence of at least three positive solutions to the nonlinear singular three-point boundary value problem is established     

Triple positive solutions for a class of third-order p-Laplacian singular boundary value problems

In this work, we study the existence of triple positive solutions for one-dimensional p-Laplacian singular boundary value problems $$\begin{array}{l}(\phi_p(y''(t)))'+f(t)g(t,\,y(t),\,y'(t),\,y''(t))=0,\quad 0<t<1,\\[3pt]ay(0)-by'(0)=0,\qquad cy(1)+dy'(1)=0,\qquad y''(0)=0,\end{array}$$ where φ _p (s)=|s| ^p?2 s,?p>1, g:[0,?1]×[0,?+∞)×R ²?[0,?+∞) and f:(0,?1)?[0,?+∞) are continuous. The nonlinear term f may be singular at t=0 and/or t=1. Firstly, Green’s function for the associated linear boundary value problem is constructed. Then, by making use of a fixed point theorem due to Avery and Peterson, sufficient conditions are obtained that guarantee the existence of triple positive solutions to the above boundary value problem. The interesting point is that the nonlinear term g involved with the first-order and second-order derivatives explicitly.     

Global solvability for the Kirchhoff equations in exterior domains of dimension three

We consider the initial (boundary) value problem for the Kirchhoff equations in exterior domains or in the whole space of dimension three, and show that these problems admit time-global solutions, provided the norms of the initial data in the usual Sobolev spaces of appropriate order are sufficiently small. We obtain uniform estimates of the L¹(R) norms with respect to time variable at each point in the domain, of solutions of initial (boundary) value problem for the linear wave equations. We then show that the estimates above yield the unique global solvability for the Kirchhoff equations.     

Multiple Positive Solutions for an n-Point Nonhomogeneous Boundary Value Problems in Banach Spaces

This paper is concerned with the solvability of an n-point nonhomogeneous boundary value problem (BVP) in Banach spaces. By using the fixed point theorem of strict-set-contractions, some sufficient conditions for the existence of at least one or two positive solutions to the n-point nonhomogeneous BVP in Banach spaces are obtained. As an application, we give one example to demonstrate our results.     

Inhomogeneous boundary value problem for a second-order singular elliptic equation in a plane sector

We consider an inhomogeneous boundary value problem in a plane sector for a model second-order singular elliptic equation. We prove the well-posed solvability of the problem in weighted function spaces of special form.     

Exact solutions of a class of second-order nonlocal boundary value problems and applications

In this paper, solutions of a class of second-order differential equations with some multi-point boundary conditions are studied. We give exact expressions of the solutions for the linear m-point boundary problems by the Green’s functions. As applications, we study uniqueness and iteration of the positive solutions for a nonlinear singular second-order m-point boundary value problem.     

奇异二阶三点边值问题的正解

应用锥中的不动点定理研究奇异二阶三点边值问题的正解的存在性。采用一种构造Green函数的方法为出发点，利用分段定义算子的手法讨论更一般的奇异二阶三点边值问题。得到了一个正解的存在性定理。其中的非线性项可以是变号的。     

A collocation method for solving a class of singular nonlinear two-point boundary value problems

In this paper, an iterative algorithm for solving singular nonlinear two-point boundary value problems is formulated. This method is basically a collocation method for nonlinear second-order two-point boundary value problems with singularities at either one or both of the boundary points. It is proved that the iterative algorithm converges to a smooth approximate solution of the BVP provided the boundary value problem is well posed and the algorithm is applied appropriately. Error estimates for uniform partitions are also investigated. It has been shown that, for sufficiently smooth solutions, the method produces order h⁴ approximations. Numerical examples are provided to show the effectiveness of the algorithm.