  We performed various tests on a cosmological model in which the string gauge
field, and its coupling to matter, is used to explain the rotation dynamics of
stars in a galaxy. Observations used include perihelion precession and galaxy
rotation curves. We solved precession motions for perturbations of 1) a
Lorenz-like force and 2) a general power law central force. For the latter
case, a simple rule judging pro/retrograde motions is derived. We attributed
the precession of solar system planets to the force due to the string field and
calculated the field strengths. We then fitted the resultant field strengths
with a profile consisting one part generated by the Sun and another background
due to other matter in the Milky Way. We used the Milky Way rotation curve to
estimate the field strength and compared it with the one found by precession.
The field strengths in another 22 galaxies are also analyzed. The strengths
form a range that spans 2 orders of magnitude and contains the value found for
the Milky Way. We also deduced from the model a relation between field
strength, galaxy size and luminosity and verified it with data of the 22
galaxies.
