  Molecular dynamics simulations of a glass-forming model system are performed
under application of a microrheological perturbation on a tagged particle. The
trajectory of that particle is studied in its underlying potential energy
landscape. Discretization of the configuration space is achieved via a
metabasin analysis. The linear and nonlinear responses of drift and diffusive
behavior can be interpreted and analyzed in terms of a continuous time random
walk. In this way the physical origin of linear and nonlinear response can be
identified. Critical forces are determined and compared with predictions from
literature.
