On solvability of focal boundary value problems for higher order functional differential equations with integral restrictions
- 1 January 2021
- journal article
- research article
- Published by University of Szeged in Electronic Journal of Qualitative Theory of Differential Equations
- No. 22,p. 1-14
- https://doi.org/10.14232/ejqtde.2021.1.22
Abstract
Sharp conditions are obtained for the unique solvability of focal boundary value problems for higher-order functional differential equations under integral restrictions on functional operators. In terms of the norm of the functional operator, unimprovable conditions for the unique solvability of the boundary value problem are established in the explicit form. If these conditions are not fulfilled, then there exists a positive bounded operator with a given norm such that the focal boundary value problem with this operator is not uniquely solvable. In the symmetric case, some estimates of the best constants in the solvability conditions are given. Comparison with existing results is also performed.Keywords
This publication has 24 references indexed in Scilit:
- Solvability of the Cauchy problem for higher-order linear functional differential equationsDifferential Equations, 2012
- On a periodic boundary value problem for third order linear functional differential equationsNonlinear Analysis, 2007
- A Fourth-Order Four-Point Right Focal Boundary Value ProblemRocky Mountain Journal of Mathematics, 2006
- Two-point boundary value problems for higher-order linear differential equations with strong singularitiesBoundary Value Problems, 2006
- Hammerstein Integral EquationsPublished by Springer Science and Business Media LLC ,1999
- Multiple positive solutions of two-point right focal boundary value problemsMathematical and Computer Modelling, 1998
- Эффективные критерии знакорегулярности и осцилляционности функций Грина двухточечных краевых задачМатематический сборник, 1997
- Positive Cones and Focal Points for a Class of nth Order Differential EquationsTransactions of the American Mathematical Society, 1978
- Total positivity, interpolation by splines, and Green's functions of differential operatorsJournal of Approximation Theory, 1971
- The sign-regularity properties of a class of Green's functions for ordinary differential equationsJournal of Differential Equations, 1969