Something that perturbates

plural of perturbance

perturbation

The quality or state of being perturbable.

That can be perturbed

plural of perturbant

A mathematical technique for finding an approximate solution to a problem that cannot be solved exactly, by starting from the exact solution of a related problem; used in modelling physical interactions between particles, etc.

(astronomy) A mathematical theory that attempts to describe the evolution of the constituents of the universe following the Big Bang