Stability tests for second order linear and nonlinear delayed models

Leonid Berezansky, Elena Braverman, Lev Idels

For the nonlinear second order Lienard-type equations with time-varying delays $$\ddot{x}(t)+\sum _{k=1}^m{f}_k(t,x(t),\dot{x}(g_k(t)))+\sum _{k=1}^l{s}_k(t,x(h_k(t)))=0,$$ global as…