## 6. ConclusionsThrough the discussions of this paper, we obtain the following
conclusions: a) The 1PN gravitational potential can be expanded in
terms of the time-slowly-changing multipole moments such as
, ,
, which can be determined by observation. Its
expansion is formally similar to that in terms of BD moments
, and
. b) For the multipole moments expansion of the
1PN potential, we suggest to adopt the standard PN gauge shown by
Eq. (12). Under this gauge, the expansion of the 1PN scalar
potential has the simplest form, and it is formally identical with the
expansion of the Newtonian gravitational potential. c) The scalar
potential under the aforesaid standard PN gauge is the simplest
generalization of the Newtonian gravitational potential in the 1PN
case. Then the conventional relation between the dynamical form-factor
and the mass quadrupole moment of the Earth
would be kept in the 1PN case, if the latter be identified as the
projection of BD moments of the Earth in its co-rotating system. d)
The vector potential under the aforesaid gauge can be also expanded in
terms of spherical harmonics. Its expansion coefficients are related
with the Cartesian time-slowly-changing multipole moments,
, and radius © European Southern Observatory (ESO) 1998 Online publication: April 28, 1998 |