Quasi-periodic response solution to scalar state-dependent delay differential equation with degenerate equilibrium (Q6587036)

The paper gave some sufficient conditions for the existence of response quasi-periodic solutions to a kind of state-dependent delay differential equation. The main difficult of the problem is the lack of regularity arising from the state-dependent delay. To overcome this difficult, the authors established the normal form of the equation and applied the parameterization method, Lanford's Lemma and KAM method. This is also the novelty of this work.