post-Newtonian formalism دیسهگرایی ِ پسا-نیوتنی disegerÃ¢yi-ye pasâ-Newtoni
*Fr.: formalisme post-newtonien*
An approximate version of → *general relativity*
that applies when the → *gravitational field*
is → *weak*, and the matter → *velocity*
is → *small*.
Post-Newtonian formalism successfully describes the gravitational field
of the solar system. It can also be applied to situations
involving compact bodies with strong internal gravity, provided
that the mutual gravity between bodies is weak.
It also provides a foundation to calculate the
→ *gravitational wave*s emitted by
→ *compact binary star system*s, as well as their
orbital evolution under radiative losses.
The formalism proceeds from the Newtonian description and then,
step by step, adds correction terms that take into account the
effects of general relativity. The correction terms are ordered in a systematic way
(from the largest effects to the smallest ones), and the progression of ever smaller
corrections is called the → *post-Newtonian expansion*. → *post-*; → *Newtonian*;
→ *formalism*. |