Positive periodic solutions of functional differential equations with infinite delay
Tom 93 / 2008
Annales Polonici Mathematici 93 (2008), 75-83
MSC: Primary 34C25.
DOI: 10.4064/ap93-1-6
Streszczenie
The author applies a generalized Leggett–Williams fixed point theorem to the study of the nonlinear functional differential equation $$ x'(t)=-a(t,x(t))x(t)+f(t,x_t). $$ Sufficient conditions are established for the existence of multiple positive periodic solutions.
