Source: wikibot/perturbation-theory
= Perturbation theory
{wiki=Perturbation_theory}
Perturbation theory is a mathematical technique used in various fields, including physics, chemistry, and engineering, to find an approximate solution to a problem that cannot be solved exactly. It is particularly useful in quantum mechanics, where systems can often be analyzed in terms of small changes (or "perturbations") to a known solvable system.