"The notion of an invariant manifold arises naturally in the asymptotic stability analysis of stationary or standing wave solutions of unstable dispersive Hamiltonian evolution equations such as the focusing semilinear Klein Gordon and Schrodinger equations. [...] These lectures are suitable for graduate students and researchers in partial differential equations and mathematical physics. For the cubic Klein Gordon equation in three dimensions all details are provided, including the derivation of Strichartz estimates for the free equation and the concentration-compactness argument leading to scattering due to Kenig and Merle."--P.[4] of cover.