Solvability for Some Higher Order Multi-Point Boundary Value Problems at Resonance

In this paper, by using the Mawhin’s continuation theorem, we obtain an existence theorem for some higher order multi-point boundary value problems at resonance in the following form: $$\begin{array}{lll}x^{(n)}(t) = f(t,x(t),x'(t),\ldots,x^{(n-1)}(t))+e(t),\ t\in(0,1),\\x^{(i)}(0) = 0, i=0,1,\ldots,n-1,\ i\neq p, \\x^{(k)}(1) = \sum\limits_{j=1}^{m-2}{\beta_j}x^{(k)}(\eta_j),\end{array}$$ where ${f:[0,1]\times \mathbb{R}^n \to \mathbb{R}=(-\infty,+\infty)}$ is a continuous function, ${e(t)\in L^1[0,1], p, k\in\{0,1,\ldots,n-1\}}$ are fixed, m ≥ 3 for p ≤ k (m ≥ 4 for p > k), ${\beta_j \in \mathbb{R}, j=1,2,\ldots,m-2, 0 < \eta_1 < \eta_2 < \cdots < \eta_{m-2} <1 }$ . We give an example to demonstrate our results.     

Existence Theory for an Arbitrary Order Fractional Differential Equation with Deviating Argument

In this paper, we are concerned with the existence criteria for positive solutions of the following nonlinear arbitrary order fractional differential equations with deviating argument

具有p-Laplace算子的一类高阶奇异边值问题解的存在性

本文研究下面问题的正解其中Φp(s)=|s|p-2s,p>1．f在点x(i)=0,i=0,．．．,n-2可能是奇异的．证明建立在Leray-Schauder拓扑度和Vitali收敛定理的基础上．     

一类多点边值问题的可解性

This paper deals with the existence of solutions for the problem
{（Фp（u′））′=f（t,u,u′）,t∈（0,1）,
u′（0）=0,u（1）=∑i=1^n-2aiu（ηi）,
where Фp（s）=｜s｜^p-2s,p〉1.0〈η1〈η2〈…〈ηn-2〈1,ai（i=1,2,…,n-2）are non-negative constants and ∑i=1^n-2ai=1.Some known results are improved under some sign and growth conditions. The proof is based on the Brouwer degree theory.     

Positive solutions to singular semipositone m-point n-order boundary value problems

In this paper, we consider the existence of positive solutions to the following Singular Semipositone m-Point n-order Boundary Value Problems (SBVP): $$\left\{\begin{array}{l@{\quad}l}(-1)^{(n-k)}x^{(n)}(t)=\lambda f(t,x(t)),&0<t<1,\\[4pt]x(1)=\sum_{i=1}^{m-2}a_ix(\eta_i),\qquad x^{(i)}(0)=0,&0\leq i\leq k-1,\\[4pt]x^{(j)}(1)=0,&1\leq j\leq n-k-1,\end{array}\right.$$ where m≥3, λ>0, a _i ∈[0,∞),(i=1,2,…,m?2),0<η ₁<η ₂<???<η _m?2<1 are constants, f:(0,1)×[0,+∞)→R is continuous and may have singularity at t=0 and/or 1. Without making any monotone-type assumption, we obtain the positive solution of the problem for λ lying in some interval, based on fixed-point index theorem in a cone.     

Positive solutions of a Lidstone boundary value problem with variable coefficient function

We establish the existence of positive solutions of the Lidstone boundary value problem $$\begin{array}{rcl}(-1)^{n}u^{(2n)}&=&\lambda a(t)f(u),\quad 0<t<1,\\[3pt]u^{(2i)}(0)&=&u^{(2i)}(1)=0,\quad 0\leq i\leq n-1\end{array}$$ for all sufficiently small positive real λ, where the function a may change sign in [0,1] and the function f:[0,∞)→R satisfies f(0)>0. We also show that our assumption is not vacuous.     

A nonlinear third order multi-point boundary value problem in the resonance case

In this paper, we discuss the following third order ordinary differential equation $$x^{\prime\prime\prime}(t)=f(t,x(t),x^{\prime}(t),x^{\prime\prime}(t))+e(t),\quad t\in (0,1)$$ with the multi-point boundary conditions $$x^{\prime}(0)=\alpha x^{\prime}(\xi),\qquad x^{\prime\prime}(0)=0,\qquad x(1)=\sum^{m-2}_{j=1}\beta_{j}x(\eta_{j})$$ where β _j (1≤j≤m?2), α∈R, 0<η ₁<η ₂<???<η _m?2<1, 0<ξ<1. When the β _j ’s have no same sign, some existence results are given for the nonlinear problems at resonance case. An example is provided in this paper.     

一类n-阶m-点奇异边值问题的正解

研究n-阶m-点奇异边值问题其中h(t)允许在t=0,t=1处奇异,f(t,v_0,v_1,…,v_(n-2))允许在v_i=0(i=0,1,…,n-2)处奇异.利用锥拉伸与压缩不动点定理得到了上述奇异边值问题正解的存在性.     

Positive solutions of higher-order singular boundary value problems

Some results of existence of positive solutions for singular boundary value problem $$\left\{\begin{array}{l}\displaystyle (-1)^{m}u^{(2m)}(t)=p(t)f(u(t)),\quad t\in(0,1),\\[2mm]\displaystyle u^{(i)}(0)=u^{(i)}(1)=0,\quad i=0,\ldots,m-1,\end{array}\right.$$ are given, where the function p(t) may be singular at t=0,1. Our analysis relies on the variational method.     

BOUNDARY VALUE PROBLEMS OF SINGULARLY PERTURBED INTEGRO－DIFFERENTIAL EQUATIONS

ＢＯＵＮＤＡＲＹＶＡＬＵＥＰＲＯＢＬＥＭＳＯＦＳＩＮＧＵＬＡＲＬＹＰＥＲＴＵＲＢＥＤＩＮＴＥＧＲＯ－ＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＺＨＯＵＱＩＮＤＥＭＩＡＯＳＨＵＭＥＩ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ,ＪｉｌｉｎＵｎｉｖｅ...     

Some necessary and sufficient conditions for existence of positive solutions for third order singular super-linear multi-point boundary value problems

We mainly study the existence of positive solutions for the following third order singular super-linear multi-point boundary value problem $$ \left \{ \begin{array}{l} x^{(3)}(t)+ f(t, x(t), x'(t))=0,\quad0 where \(0\leq\alpha_{i}\leq\sum_{i=1}^{m_{1}}\alpha_{i}<1\) , i=1,2,…,m ₁, \(0<\xi_{1}< \xi_{2}< \cdots<\xi_{m_{1}}<1\) , \(0\leq\beta_{j}\leq\sum_{i=1}^{m_{2}}\beta_{i}<1\) , j=1,2,…,m ₂, \(0<\eta_{1}< \eta_{2}< \cdots<\eta_{m_{2}}<1\) . And we obtain some necessary and sufficient conditions for the existence of C ¹[0,1] and C ²[0,1] positive solutions by means of the fixed point theorems on a special cone. Our nonlinearity f(t,x,y) may be singular at t=0 and t=1.     

Solvability of a higher-order multi-point boundary value problem at resonance

Based on the coincidence degree theory of Mawhin, we get a new general existence result for the following higher-order multi-point boundary value problem at resonance

Sequential algorithms of optimal order global error for the uniform recovery of functions with monotone (r-1) derivatives

В работе на конкретно м примере устанавлив ается превосходство после довательных алгоритмов над пасси вными. Именно, описан последовательный ал горитм для выбораN узлов (т.е.N (ε, x, K ⁰)≦N точек и змерения неизвестно й функцииx∈K ⁰) для равном ерного приближения с заданн ой глобальной погреш ностьюε, на отрезке [0,1] на классеK ⁰ ф ункций с ограниченными и мон отонными (R?1)-ыми произ водными. Доказано, что для любо гоx изK ⁰ для упомянуто го алгоритма, $$N(\varepsilon ,x,K^0 ) \leqq \left\{ {\frac{{(x^{(R - 1)} (b) - x^{(R - 1)} (a))(b - a)^{(R - 1)} }}{g}} \right\}^{(1/R)} g_R $$ где величинаg _R зависи т лишь отR и отK ⁰. С другой стороны, дока зано, что глобальная п огрешность любого пассивного ме тода (т.е. при выборе сразу вс ей системы узлов) имее т порядок (R? 1): для любогоN иt ₁,...,t _N ∈ ∈[0,1] существуют две фун кциих ₁,х ₂ с монотонн ыми (R?1)-ыми производными, удовле т-воряющими условию ¦x ^R ?1¦≦M, гдеМ — произвольное фиксированное полож ительное число, такие, что $$x_1 (t_i ) = x_2 (t_i ),i = 1,...,N,\left\| {x - y} \right\|_{C[0,1]} \geqq h_R N^{ - R + 1} $$ , где константаh _R завис ит лишь отR иM. По-новому освещаются некоторые свойства б азисных сплайн-функций, (напри мер, их положительность) опи саны общие методы кон струкции и оценки последовател ьных алгорит-мов для основных задач те ории аппроксимации (к вадратуры, дифференцирования) ф ункций с (полу) ограниченнымиR-ыми производными и п ри неточных измеренияхN значений этих функций.     

Strong convergence theorems for a Mann-type iterative scheme for a family of Lipschitzian mappings

In the paper, we obtain the existence of triple positive solutions for the following second order three-point boundary value problem, $$\left\{\begin{array}{l}(\phi_p(u'))'(t)+q(t)f(u(t),u'(t),(Tu)(t),(Su)(t))=0,\quad 0\leq t\leq1,\\[4pt]u'(0)=\beta u'(\eta),\qquad u(1)=g(u'(1)),\end{array}\right.$$ where $\phi_{p}(s)=|s|^{p-2}s,p>1,\beta\in[0,1),\eta\in(0,\frac{1}{2}]$ , T and S are all linear operators, g(t) is continuous.     

The method of lower and upper solutions for third order singular four point boundary value problems

We mainly study the existence of positive solutions for the following third order singular four point boundary value problem $$\begin{cases}x^{(3)}(t)+f(t,x,x',-x'')=0,\quad 0<t<1,\\x(0)-\alpha x(\xi)=0,\quad x'(1)-\beta x'(\eta)=0,\quad x''(0)=0.\end{cases}$$ where 0≤α<1, 0≤β<1, 0<ξ<1,0<η<1. And we obtain some necessary and sufficient conditions for the existence of C ²[0,1] positive solutions by means of the lower and upper solution method. Our nonlinearity f(t,x,y,z) may be singular at x,y,z,t=0 and/or t=1.     

An application of Schauder's fixed point theorem with respect to higher order BVPs

We shall provide conditions on the function . The higher order boundary value problem

has at least one solution.

     

半拟线性p-Laplacian问题结点解的存在性

In this paper, we study the existence of nodal solutions for the following problem:-(φ_p(x′))′= α(t)φ_p(x~+) + β(t)φ_p(x~-) + ra(t)f(x), 0 t 1,x(0) = x(1) = 0,where φ_p(s) = |s|~(p-2)s, a ∈ C([0, 1],(0, ∞)), x~+= max{x, 0}, x~-=- min{x, 0}, α(t), β(t) ∈C[0, 1]; f ∈ C(R, R), sf(s) 0 for s ≠ 0, and f_0, f_∞∈(0, ∞), where f_0 = lim_|s|→0f(s)/φ_p(s), f_∞ = lim|s|→+∞f(s)/φ_p(s).We use bifurcation techniques and the approximation of connected components to prove our main results.     

A Hardy type inequality for W m,1(0, 1) functions

In this paper, we consider functions ${u\in W^{m,1}(0,1)}$ where m ≥ 2 and u(0) = Du(0) = · · · = D ^m-1 u(0) = 0. Although it is not true in general that ${\frac{D^ju(x)}{x^{m-j}} \in L^1(0,1)}$ for ${j\in \{0,1,\ldots,m-1\}}$ , we prove that ${\frac{D^ju(x)}{x^{m-j-k}} \in W^{k,1}(0,1)}$ if k ≥ 1 and 1 ≤ j + k ≤ m, with j, k integers. Furthermore, we have the following Hardy type inequality, $$\left\|{D^k\left({\frac{D^ju(x)}{x^{m-j-k}}}\right)}\right\|_{L^1(0,1)} \leq \frac {(k-1)!}{(m-j-1)!} \|{D^mu}\|_{L^1(0,1)},$$ where the constant is optimal.     

On Nonlocal Boundary Value Problems for Nonlinear Integro-differential Equations of Arbitrary Fractional Order

In this paper, we prove the existence of solutions of a nonlocal boundary value problem for nonlinear integro-differential equations of fractional order given by $$ \begin{array}{ll} ^cD^qx(t) = f(t,x(t),(\phi x)(t),(\psi x)(t)), \quad 0 < t < 1,\\x(0) = \beta x(\eta), x'(0) =0, x''(0) =0, \ldots, x^{(m-2)}(0) =0, x(1)= \alpha x(\eta), \end{array}$$ where $${q \in (m-1, m], m \in \mathbb{N}, m \ge 2}$, $0< \eta <1$$ , and ${\phi x}$ and ${\psi x}$ are integral operators. The existence results are established by means of the contraction mapping principle and Krasnoselskii’s fixed point theorem. An illustrative example is also presented.     

On proper oscillatory and vanishing-at-infinity solutions of differential equations with a deviating argument

Sufficient conditions are found for the existence of multiparametric families of proper oscillatory and vanishing-at-infinity solutions of the differential equation $$u^{(n)} (t) = g\left( {t, u(\tau _0 (t)), \ldots ,u^{(m - 1)} (\tau _{m - 1} (t))} \right)$$ , wheren≥4,m is the integer part of π/2,g:R ₊×R ^m →R is a function satisfying the local Carathéodory conditions, and τ _i :R ₊→R(i=0,...,m?1) are measurable functions such that τ _i (t) →+∞ fort→+∞(i=0,...,m?1).