Résumé
Phys.Lett.B645:222-227,2007 It is shown that gravitinos with mass m_{3/2} ~ 0.1-1 MeV may provide
suitable cold dark matter candidates in scenarios of gauge mediated
supersymmetry breaking (GMSB) under SO(10) grand unification coupled to
supergravity, which accommodate a messenger sector of mass scale M_X ~ 10^6
GeV. This is due to the combined effects of renormalizable loop-suppressed
operators and generic non-renormalizable ones governing the dilution of a
pre-existing equilibrium gravitino abundance via messenger decay. The above
range of gravitino and messenger masses can be accommodated in indirect GMSB
scenarios. The gravitino abundance does not depend on the post-inflationary
reheat temperature and it is shown that leptogenesis can generate successfully
the baryon asymmetry.