Talk:Linearized gravity/to do

explain the usage of the weak-field approximation as a means to justify the $8\pi G$ constant in Einstein's Field Equations.
show how the use of the harmonic gauge can derive the quadrupole radiation formula and how binary systems emit gravitational radiation.
expand and link to background article on multipole expansion: motivate and define mass, momentum, stress monopoles, reduced quadrupole tensor, explain relation to harmonic expansion of potential, explain Newtonian, Weyl, and relativistic multipoles, cite Stephani's textbook and other sources, link to any relevant discusion of multipoles in Newtonian theory and electromagnetism (see Category:Vector calculus and Category:Potential theory for some possibilities).
elaborate on the mathematical description (possibly in a separate page from which will be linked here) on linearized plane waves under the transverse-traceless gauge. discussing their curvature, different polarizations, etc; along with a discussion in terms of GEM formalism. compare and link to strong field plane waves.
discuss usage of linearized gravity in connection to weak-field gravitational lensing. provide a link.

(please be very careful about changing equations since nonexperts might easily introduce errors)