perturbation theory

1. A set of mathematical methods for obtaining approximate solutions to complex equations for which no exact solution is possible or known, generally involving an iterative algorithm in which each new term contributing to the solution has less significance than the last. In quantum physics, Feynman diagrams are used to calculate the terms for the perturbation theory solution of interactions between particles.

Example Sentences

He turned his thesis into the book Geometric Perturbation Theory in Physics on the new developments in differential geometry.

From The Daily Beast