About sign-constancy of Green’s function of a two-point problem for impulsive second order delay equations

We consider the following second order differential equation with delay $$ \begin{cases} \begin{split} (Lx)(t)&\equiv{x''(t)+\sum_{j=1}^p {a_{j}(t)x'(t-\tau_{j}(t))}+\sum_{j=1}^p {b_{j}(t)x(t-\theta_{j}(t))}}=f(t), & t\in[0,\omega] \end{split} \\ x(t_k)=\gamma_{k}x(t_k-0), \...

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Bibliographic Details
Main Authors: Alexander Domoshnitsky, Guy Landsman, Shlomo Yanetz
Format: Article
Language:English
Published: University of Szeged 2016-08-01
Series:Electronic Journal of Qualitative Theory of Differential Equations
Subjects:
Online Access:http://www.math.u-szeged.hu/ejqtde/periodica.html?periodica=1&paramtipus_ertek=publication&param_ertek=4268
Description
Summary:We consider the following second order differential equation with delay $$ \begin{cases} \begin{split} (Lx)(t)&\equiv{x''(t)+\sum_{j=1}^p {a_{j}(t)x'(t-\tau_{j}(t))}+\sum_{j=1}^p {b_{j}(t)x(t-\theta_{j}(t))}}=f(t), & t\in[0,\omega] \end{split} \\ x(t_k)=\gamma_{k}x(t_k-0), \ x'(t_k)=\delta_{k}x'(t_k-0), \quad k=1,2,\dots,r. \end{cases} $$ In this paper we find sufficient conditions of positivity of Green's functions for this impulsive equation coupled with two-point boundary conditions in the form of theorems about differential inequalities. Choosing the test function in these theorems, we obtain simple sufficient conditions.
ISSN:1417-3875
1417-3875