Open AccessThe Existence of Periodic Solutions of Delay Differential Equations by -Conley Index Theory
Author(s) -
Huafeng Xiao
Publication year - 2022
Publication title -
journal of function spaces
Language(s) - English
Resource type - Journals
eISSN - 2314-8896
pISSN - 2314-8888
DOI - 10.1155/2022/3396716
Subject(s) - infinity , mathematics , ordinary differential equation , delay differential equation , differential equation , mathematical analysis
In this paper, the E + -Conley index theory has been used to study the existence of periodic solutions of nonautonomous delay differential equations (in short, DDEs). The variational structure for DDEs is built, and the existence of periodic solutions of DDEs is transferred to that of critical points of the associated function. When DDEs are 2 π -nonresonant, some sufficient conditions are obtained to guarantee the existence of periodic solutions. When the system is 2 π -resonant at infinity, by making use a second disturbing of the original functional, some sufficient conditions are obtained to guarantee the existence of periodic solutions to DDEs.