https://doi.org/10.1140/epjc/s10052-017-4840-7
Regular Article - Theoretical Physics
Cosmology with bulk viscosity and the gravitino problem
Consequences of imperfect fluids on gravitino production
1
Dipartimento di Fisica “E.R. Caianiello” Universitá di Salerno, 84084, Fisciano, SA, Italy
2
INFN-Gruppo Collegato di Salerno, Dipartimento di Fisica “E.R. Caianiello” Universitá di Salerno, 84084, Fisciano, SA, Italy
* e-mail: lambiase@sa.infn.it
Received:
6
October
2016
Accepted:
18
April
2017
Published online:
5
May
2017
The gravitino problem is revisited in the framework of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. Dissipative effects (or bulk viscosity effects) arise owing to the different cooling rates of the fluid components. We show that the effects of the bulk viscosity allow one to avoid the late abundance of gravitinos. In particular, for particular values of the parameters characterizing the cosmological model, the gravitino abundance turns out to be weakly depending on the reheating temperature.
© The Author(s), 2017
