The Cosmological Supersymmetron
  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. 
Philippe Brax, Anne-Christine Davis, Hans A. Winther
astro-ph.CO hep-ph hep-th