Perturbation Theory
نویسنده
چکیده
1 Definition of the subject and its importance Perturbation Theory: Computation of a quantity depending on a parameter ε starting from the knowledge of is value for ε = 0 by deriving a power series expansion in ε, under the assumption of its existence, and if possible discussing the interpretation of the series. Perturbation theory is very often the only way to get a glimpse of the properties of systems whose equations cannot be “explicitly solved” in computable form. Its importance is witnessed by its applications in Astronomy, where it lead not only to the discovery of new planets (Neptune) but also to the disovery of Chaotic motions, with the completion of the Copernican revolution and the full understanding of the role of Aristotelian Physics
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