Non-Linear Neutron Star Oscillations Viewed As Deviations From An Equilibrium State

A numerical technique is presented which facilitates the evolution of non-linear neutron star oscillations with a high accuracy essentially independent of the oscillation amplitude. We apply this technique to radial neutron star oscillations in a Lagrangian formulation and demonstrate the superior performance of the new scheme compared with "conventional" techniques. We apply the new technique to study the coupling of eigenmodes due to non-linear effects.