Massimiliano Berti, Luca Biasco, Michela Procesi KAM theory for the reversible derivative wave equation (1191K, pdf) ABSTRACT. We prove the existence of Cantor families of small amplitude, analytic, quasi-periodic solutions of derivative wave equations, with zero Lyapunov exponents and whose linearized equation is reducible to constant coefficients. This result is derived by an abstract KAM theorem for in finite dimensional reversible dynamical system