Chapter one is dedicated to an introduction of notations, and to a general presentation the dark matter candidates that are then investigated. Neutrinos are reviewed, since they are by far the most famous dark matter candidates, especially after the recent Super-Kamiokande results. Moreover, they are often used as a reference scenario. Other dark matter candidates, like gravitinos and volatile particles, are also presented. A section is dedicated to inflation, with particular care to the predictions that it implies on the primordial spectral index n.
- Chapter two provides a derivation of the relevant equations that are needed to study the evolution of perturbations in linear theory. The derivation is performed for the volatile models, and final equations are given for all the models presented.
- Chapter three introduces the basic tools that are needed for the comparison with the data at a linear stage. The spectra of the models are presented and discussed.
- Chapter four is dedicated to the comparison of the models to the observations.
A final summary and discussion of the results conclude this thesis.
