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

"This problem is solved by the new method of wavefunction matching by mapping the complicated problem in a first approximation to a simple model system that does not have such sign oscillations and then treating the differences in perturbation theory," says Prof. Ulf-G.

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Since the new wavefunctions are similar to those of the easily computable interaction, the researchers can now perform calculations with the easily computable interaction and apply a standard procedure for handling small corrections -- called perturbation theory.

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He wrote three research papers during his incarceration, on topics including inflation theory and cosmological perturbation theory.

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