R. Hakl, A. Lomatidze, and B. Puza

On periodic solutions of first order nonlinear funcional differential equations of non-Volterra's type

abstract:
Nonimprovable effective sufficient conditions for the existence and uniqueness of an $\omega$-periodic solution of the equation $$ u'(t)=f(u)(t), $$ where $f:C_\omega(R)\to L_\omega(R)$ is a continuous operator satisfying the Caratheodory conditions, are established.

Mathematics Subject Classification: 34K13.

Key words and phrases: Nonlinear differential equations, periodic solutions, existence and uniqueness.