Galactic dark matter effects from purely geometrical aspects of General
  Relativity
  We study disc galaxies in the framework of General Relativity to focus on the
possibility that, even in the low energy limit, there are relevant corrections
with respect to the purely Newtonian approach. Our analysis encompasses the
model both considering a low energy expansion and exact solutions, making it
clear the connection between these different approaches. In particular, we
focus on two different limits: the well known gravitomagnetic analogy and a new
limit, called strong gravitomagnetism, which has corrections in c of the same
order as the Newtonian terms. We show that these two limits of the general
class of solution can account for the observed flat velocity profile, contrary
to what happens using Newtonian models, where a dark matter contribution is
required. Hence, we suggest a geometrical origin for a certain amount of dark
matter effects.
