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post-Newtonian formalism

(PN formalism)
(method of approximating GR-based mechanics from Newtonian mechanics)

A PN formalism (for post-Newtonian formalism) is a method of representing dynamics as Newton's laws along with a term (or terms) covering the differences between Newtonian mechanics and the effects of general relativity (GR). A perfect fit would be nice but generally an approximation of GR is what is attainable, which may be sufficiently accurate to be useful. Variants of this notion have been used since GR's invention because GR calculations can be extremely difficult to carry out in a straight-forward manner so good approximations have value: Einstein used such methods from the beginning. The PN formalism uses an expansion such that approximations can be made using one, two, or more terms, such versions labeled 1PN, 2PN, 3PN, etc.

A post-Newtonian correction term (PN correction term) is a term added to a (Newtonian) formula/equation to include or approximate the effects of relativity.


(gravity,method,relativity)
Further reading:
https://en.wikipedia.org/wiki/Post-Newtonian_expansion
https://www.einstein-online.info/en/explandict/post-newtonian-formalism/
http://bcc.impan.pl/13Gravitational/uploads/lecture2.pdf
http://physics.gmu.edu/~rubinp/ires/Vartak_Summer_Report.pdf
https://kiss.caltech.edu/workshops/quantum/presentations/turyshev.pdf
https://einstein.stanford.edu/RESOURCES/KACST_docs/KACSTlectures/KACST-GPB-Theory.pdf

Referenced by pages:
correction term
parameterized post-Newtonian formalism (PPN formalism)

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