On periodic solutions to autonomous retarded functional differential equations

Zhanyuan Hou
1990 Bulletin of the Australian Mathematical Society  
ON PERIODIC SOLUTIONS TO AUTONOMOUS RETARDED FUNCTIONAL DIFFERENTIAL EQUATIONS ZHANYUAN HOU Under the assumption that C o = C([-r, 0], S"" 1^) ) is positively invariant for a > 0, two necessary and sufficient conditions are obtained for an autonomous retarded functional differential equation to have a non-trivial periodic solution in C*. Moreover, a feasible sufficient condition is given, which is better for n = 2 than that given by Dos Reis and Baroni.
doi:10.1017/s0004972700018219 fatcat:zokoy5iffra5jozwbdxa2nq2he