Newtonian explanation of galaxy rotation curves based on distribution of
  baryonic matter
  Circular velocities of stars and gas in galaxies generally do not decline in
accordance with widely expected Keplerian fall-off in velocities further from
the galactic nucleus. Two main groups of theories were proposed to explain the
supposed discrepancy--first, the most commonly accepted, is the suggestion of
the existence of large non-baryonic dark matter halo, and, second are theories
advocating some modification to the law of gravity. So far however, there is no
empirical evidence for either dark matter or modified gravity. Here we show
that a broad range of galaxy rotation curves can be explained solely in
accordance with Newton's law of gravity by modeling the distribution of
baryonic matter in a galaxy. We demonstrate that the expectation of Keplerian
fall-off is incorrect, and that a large number of likely galaxy mass
distribution profiles should in fact produce flat or accelerating rotation
curves similar to those observed in reality. We further support our theoretical
findings with the model fit of 47 rotation curves of real galaxies,
representing a broad range of galactic types and sizes, and achieving
correlation of expected and observed velocities of over 0.995 for all cases.
Our results make theories of exotic dark matter or modified gravity unnecessary
for the explanation of galaxy rotation curves.
