Séminaire / Seminar GReCO |
| « The Prospects of determining the expansion history of the Universe with the three dimensional cosmic shear » |
|
R. Brustein |
| The accelerated expansion of our universe, and consequently the conclusion that it apparently contains a substantial amount of dark energy are still unexplained. Future comprehensive cosmological surveys will provide unprecedented wealth of data. Will we be able to use the data to determine the expansion history of the universe and the nature of dark energy? I will explain why in order to be able to use the cosmological data to learn about fundamental physics we need to develop model independent expressions for cosmological perturbations probes. I will present an example: the total equation of state parameter (EOS) in terms of the 3D cosmic shear. I will then describe a preliminary quantitative investigation showing that precise measurements of the 3D cosmic shear will indeed be able to significantly improve the model-independent constraints on the total cosmic EOS and hence on the expansion history of the universe. I will argue that it is necessary to combine the results of several different precise observations in addition to the cosmic shear. |
|
lundi 1 octobre 2007 - 11:00 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |