Gravitino cosmology with a very light neutralino
  It has been shown that very light or even massless neutralinos are consistent with all current experiments, given non-universal gaugino masses. Furthermore, a very light neutralino is consistent with astrophysical bounds from supernov{\ae} and cosmological bounds on dark matter. Here we study the cosmological constraints on this scenario from Big Bang nucleosynthesis taking gravitinos into account and find that a very light neutralino is even favoured by current observations. 
Herbi K. Dreiner (Bonn), Marja Hanussek (Bonn), Jong-Soo Kim   (Dortmund, Adelaide), and Subir Sarkar (Oxford)
hep-ph astro-ph.CO astro-ph.HE