TY  - JOUR
ID  - Qian2019
LB  - Qian2019
AU  - Qian, Chuanxi
AU  - Smith, Justin
TI  - On existence and global attractivity of periodic solutions of nonlinear delay differential equations
ST  - On existence and global attractivity of periodic solutions of nonlinear delay differential equations
JO  - Opuscula Math.
JA  - Opuscula Math.
JF  - Opuscula Mathematica
PY  - 2019
VL  - 39
IS  - 6
SP  - 839
EP  - 862
DO  - https://doi.org/10.7494/OpMath.2019.39.6.839
UR  - https://doi.org/10.7494/OpMath.2019.39.6.839
AB  - Consider the delay differential equation with a forcing term \[\tag{\(\ast\)} x'(t)=-f(t,x(t))+g(t,x(t-\tau ))+r(t), \quad t \geq 0\] where \(f(t,x): [0,\infty) \times [0,\infty) \to \mathbb{R}\), \(g(t,x): [0,\infty) \times [0,\infty) \to [0,\infty)\) are continuous functions and \(\omega\)-periodic in \(t\), \(r(t): [0,\infty) \to\mathbb{R}\) is a continuous function and \(\tau \in (0,\infty)\) is a positive constant. We first obtain a sufficient condition for the existence of a unique nonnegative periodic solution \(\tilde{x}(t)\) of the associated unforced differential equation of Eq. (\(\ast\)) \[\tag{\(\ast\ast\)} x'(t)=-f(t,x(t))+g(t,x(t-\tau)), \quad t \geq 0.\] Then we obtain a sufficient condition so that every nonnegative solution of the forced equation (\(\ast\)) converges to this nonnegative periodic solution \(\tilde{x}(t)\) of the associated unforced equation(\(\ast\ast\)). Applications from mathematical biology and numerical examples are also given.
KW  - delay differential equation
KW  - periodic solution
KW  - global attractivity
SN  - 1232-9274
ER  -