Differentiation and boundaries

This research is built upon the determination of the Eigenpairs of one and two dimensional positive differential operators with periodic boundary conditions. The Schrödinger equation was solved for positive operators in both one and two dimensions. Fourier series were used to express the derivatives as the summation of Fourier terms. This led to a novel approach for the calculation of the eigenmodels of a perturbed potential well. The perturbation can be done via an electric field applied to the potential well.

88p runthenight07 01-03-2023 8 3   Download

The objective of the thesis is to develop the iterative method and combining it with other methods to study qualitative and especially the method of solving some two-point boundary problems for the fourth-order differential equations and systems, arising in beam bending theory without using condition of growth rate at infinity, Nagumo condition, etc. of the right-hand side function.

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The thesis proposes a simple but very effective method to study the unique solvability and an iterative method for solving five boundary value problems for nonlinear fourth order ordinary differential equations with different types of boundary conditions and two boundary value problems for a biharmonic equation and a biharmonic equation of Kirchhoff type by using the reduction of these problems to the operator equations for the function to be sought or an intermediate function.

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TWO-POINT BOUNDARY VALUE PROBLEMS FOR HIGHER-ORDER LINEAR DIFFERENTIAL EQUATIONS WITH STRONG SINGULARITIES R. P. AGARWAL AND I. KIGURADZE Received 4 April 2004; Revised 11 December 2004; Accepted 14 December 2004 For strongly singular higher-order linear differential equations together with two-point conjugate and right-focal boundary conditions, we provide easily verifiable best possible conditions which guarantee the existence of a unique solution. Copyright © 2006 Hindawi Publishing Corporation. All rights reserved. 1. Statement of the main results 1.1.

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ON A BOUNDARY VALUE PROBLEM FOR NONLINEAR FUNCTIONAL DIFFERENTIAL EQUATIONS ROBERT HAKL Received 21 August 2004 and in revised form 1 March 2005 We consider the problem u (t) = H(u)(t) + Q(u)(t), u(a) = h(u), where H,Q : C([a,b];R) αβ → L([a,b];R) are, in general, nonlinear continuous operators, H ∈ ab (g0 ,g1 , p0 , p1 ), and h : C([a,b];R) → R is a continuous functional. Efficient conditions sufficient for the solvability and unique solvability of the problem considered are established. 1. Notation The following notation is used throughout the paper: N is the set of all natural numbers....

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ON A PERIODIC BOUNDARY VALUE PROBLEM FOR SECOND-ORDER LINEAR FUNCTIONAL DIFFERENTIAL EQUATIONS S. MUKHIGULASHVILI Received 26 October 2004 and in revised form 7 March 2005 Unimprovable efficient sufficient conditions are established for the unique solvability of the periodic problem u (t) = (u)(t) + q(t) for 0 ≤ t ≤ ω, u(i) (0) = u(i) (ω) (i = 0,1), where ω 0, : C([0,ω]) → L([0,ω]) is a linear bounded operator, and q ∈ L([0,ω]). 1. Introduction Consider the equation u (t) = (u)(t) + q(t) for 0 ≤ t ≤ ω with the periodic boundary conditions u(i) (0) = u(i)...

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MAXIMAL REGULAR BOUNDARY VALUE PROBLEMS IN BANACH-VALUED WEIGHTED SPACE RAVI P. AGARWAL, MARTIN BOHNER, AND VELI B. SHAKHMUROV Received 10 July 2004 This study focuses on nonlocal boundary value problems for elliptic ordinary and partial differential-operator equations of arbitrary order, defined in Banach-valued function spaces. The region considered here has a varying bound and depends on a certain parameter.

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ON DELAY DIFFERENTIAL EQUATIONS WITH NONLINEAR BOUNDARY CONDITIONS TADEUSZ JANKOWSKI Received 21 July 2004 The monotone iterative method is used to obtain sufficient conditions which guarantee that a delay differential equation with a nonlinear boundary condition has quasisolutions, extremal solutions, or a unique solution. Such results are obtained using techniques of weakly coupled lower and upper solutions or lower and upper solutions. Corresponding results are also obtained for such problems with more delayed arguments.

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MULTIPLICITY RESULTS FOR A CLASS OF ASYMMETRIC WEAKLY COUPLED SYSTEMS OF SECOND-ORDER ORDINARY DIFFERENTIAL EQUATIONS FRANCESCA DALBONO AND P. J. MCKENNA Received 1 November 2004 We prove the existence and multiplicity of solutions to a two-point boundary value problem associated to a weakly coupled system of asymmetric second-order equations. Applying a classical change of variables, we transform the initial problem into an equivalent problem whose solutions can be characterized by their nodal properties.

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NONSMOOTH AND NONLOCAL DIFFERENTIAL EQUATIONS IN LATTICE-ORDERED BANACH SPACES ¨ SIEGFRIED CARL AND S. HEIKKILA Received 7 September 2004 We derive existence results for initial and boundary value problems in lattice-ordered Banach spaces. The considered problems can be singular, functional, discontinuous, and nonlocal. Concrete examples are also solved. 1. Introduction In this paper, we apply fixed point results for mappings in partially ordered function spaces to derive existence results for initial and boundary value problems in an ordered Banach space E.

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