perturbation theory

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.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.