Philippe Brax, Anne-Christine Davis, Hans A. Winther
Recently, a supersymmetric model of dark energy coupled to cold dark matter,
the supersymmetron, has been proposed. In the absence of cold dark matter, the
supersymmetron field converges to a supersymmetric minimum with a vanishing
cosmological constant. When cold dark matter is present, the supersymmetron
evolves to a matter dependent minimum where its energy density does not vanish
and could lead to the present acceleration of the Universe. The supersymmetron
generates a short ranged fifth force which evades gravitational tests. It could
lead to observable signatures on structure formation due to a very strong
coupling to dark matter. We investigate the cosmological evolution of the
field, focusing on the linear perturbations and the spherical collapse and find
that observable modifications in structure formation can indeed exist.
Unfortunately, we find that when the growth-rate of perturbations is in
agreement with observations, an additional cosmological constant is required to
account for dark energy. In this case, effects on large scale structures are
still present at the non-linear level which are investigated using the
spherical collapse approach.
View original:
http://arxiv.org/abs/1112.3676
No comments:
Post a Comment