نبذة مختصرة : My research focuses on the extraction of the signal imprinted by the BAO on the galaxy distribution. The BAO feature is a bump at ∼ 150Mpc in the two-points correlation function of the matter in the Universe. This corresponds to maximum distance travelled by acoustic waves in the matter-radiation fuid during the period from matter/radiation equality to their decoupling at z ∼1100. An excess density at a radius of 150 Mpc was left after decoupling around each dark-matter density peak. The final goal of my work is to perform a complete analysis of the data available up to summer 2011 in SDSS III/BOSS in order to give constraints on isotropised distance DV and constraint the dark energy equation of state parameters w0 and wa . With such observations, one wants to check if the data is consistent with the so-called cosmological constant (corresponding to w0 =1 and wa = 0) or if the dark energy equation of state shows a time evolution (wa ̸= 0) pointing to more complex dark energy scenarios. I studied and tested data analysis tools with log normal simulations and the public DR7 to achieve this goal. I studied the redshift distortions with simulations in the linear regime and I developed a optimization method for the correlation function estimator. The second part of my my work was focused in the analysis of BOSS data.There are to main programs in the SDSS III/BOSS pro ject: the Luminous Red Galaxies catalogue anda new technique based on quasars using the Lyman-alpha forest. I have focused my research on the LRG science. I performed a complete analysis of BOSS-CMASS sample from catalog construction, systematic corrections and cosmological constrains. ; Le travail de ma thèse s'est concentré sur l'extraction du signal laissé par les BAO dans la distribution des galaxies. Celui se présente sous forme d'un pic autour de 150 Mpc dans la fonction de corrélation à deux point de la matière. Cette échelle correspond à la distance parcourue par l'onde acoustique dans le fuide matière-radiation entre la période d'égalité ...
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