Scalar fields as dark matter in spiral galaxies

Abstract
We present a model for the dark matter in spiral galaxies, which is a result of a static and axial symmetric exact solution of the Einstein-dilaton theory. We suppose that dark matter is a scalar field endowed with a scalar potential. We obtain that (a) the effective energy density goes like 1/(r 2 +rc 2 ) and (b) the resulting circular velocity profile of test particles is in good agreement with the observed one.