Περίληψη:
We consider the possibility that the dark matter is coupled through its
mass to a scalar field associated with the dark energy of the Universe.
In order for such a field to play a role at the present cosmological
distances, it must be effectively massless at galactic length scales. We
discuss the effect of the field on the distribution of dark matter in
galaxy halos. We show that the profile of the distribution outside the
galaxy core remains largely unaffected and the approximately flat
rotation curves persist. The dispersion of the dark matter velocity is
enhanced by a potentially large factor relative to the case of zero
coupling between dark energy and dark matter. The counting rates in
terrestrial dark matter detectors are similarly enhanced. Existing
bounds on the properties of dark matter candidates can be extended to
the coupled case, by taking into account the enhancement factor. (c)
2005 Elsevier B.V. All rights reserved.
