Effect of resonance on the existence of periodic solutions for strongly damped wave equation

Piotr Kokocki

We are interested in the differential equation $\ddot{u}(t)=-Au(t)-cA\dot{u}(t)+\lambda u(t)+F(t,u(t))$, where $c>0$ is a damping factor, $A$ is a sectorial operator and $F$ is…