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On some nonlinear alternatives of Leray-Schauder type and functional integral equations

Bapurao Chandra Dhage (2006)

Archivum Mathematicum

In this paper, some new fixed point theorems concerning the nonlinear alternative of Leray-Schauder type are proved in a Banach algebra. Applications are given to nonlinear functional integral equations in Banach algebras for proving the existence results. Our results of this paper complement the results that appear in Granas et. al. (Granas, A., Guenther, R. B. and Lee, J. W., Some existence principles in the Caratherodony theory of nonlinear differential system, J. Math. Pures Appl. 70 (1991),...

On the existence and the stability of solutions for higher-order semilinear Dirichlet problems

Marek Galewski, M. Płócienniczak (2007)

Czechoslovak Mathematical Journal

We investigate the existence and stability of solutions for higher-order two-point boundary value problems in case the differential operator is not necessarily positive definite, i.e. with superlinear nonlinearities. We write an abstract realization of the Dirichlet problem and provide abstract existence and stability results which are further applied to concrete problems.

On the existence of multiple solutions for a nonlocal BVP with vector-valued response

Andrzej Nowakowski, Aleksandra Orpel (2006)

Czechoslovak Mathematical Journal

The existence of positive solutions for a nonlocal boundary-value problem with vector-valued response is investigated. We develop duality and variational principles for this problem. Our variational approach enables us to approximate solutions and give a measure of a duality gap between the primal and dual functional for minimizing sequences.

On the existence of one-signed periodic solutions of some differential equations of second order

Jan Ligęza (2006)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

We study the existence of one-signed periodic solutions of the equations x ' ' ( t ) - a 2 ( t ) x ( t ) + μ f ( t , x ( t ) , x ' ( t ) ) = 0 , x ' ' ( t ) + a 2 ( t ) x ( t ) = μ f ( t , x ( t ) , x ' ( t ) ) , where μ > 0 , a : ( - , + ) ( 0 , ) is continuous and 1-periodic, f is a continuous and 1-periodic in the first variable and may take values of different signs. The Krasnosielski fixed point theorem on cone is used.

On the existence of optimal controls for nonlinear infinite dimensional systems

Antonella Fiacca, Nikolaos S. Papageorgiou, Francesca Papalini (1998)

Czechoslovak Mathematical Journal

We consider nonlinear systems with a priori feedback. We establish the existence of admissible pairs and then we show that the Lagrange optimal control problem admits an optimal pair. As application we work out in detail two examples of optimal control problems for nonlinear parabolic partial differential equations.

On the solvability of a fourth-order multi-point boundary value problem

Yuqiang Feng, Xincheng Ding (2012)

Annales Polonici Mathematici

We are concerned with the solvability of the fourth-order four-point boundary value problem ⎧ u ( 4 ) ( t ) = f ( t , u ( t ) , u ' ' ( t ) ) , t ∈ [0,1], ⎨ u(0) = u(1) = 0, ⎩ au”(ζ₁) - bu”’(ζ₁) = 0, cu”(ζ₂) + du”’(ζ₂) = 0, where 0 ≤ ζ₁ < ζ₂ ≤ 1, f ∈ C([0,1] × [0,∞) × (-∞,0],[0,∞)). By using Guo-Krasnosel’skiĭ’s fixed point theorem on cones, some criteria are established to ensure the existence, nonexistence and multiplicity of positive solutions for this problem.

Currently displaying 341 – 360 of 538