Since the end of the 90s, we introduced the well known Dark Energy in order to reproduce the acceleration of the Universe s expansion measured using far supernovae. However, another possibility is to consider that the general relativity model is not perfect at large scale and modify it. The second approach is more popular with time since we do not found a physical interpretation to the Dark Energy.
The Large Scale Structures formation is governed by the relative evolution of the scale factor in over-densities and the background Universe as well as the gravity model. After the turn-around, the structures start to collapse and then, if have enough time, can virialize. At the scale larger than galaxy clusters, the structures are generally still collapsing laying a coherent peculiar velocity which depends on the gravitational model and the energetic components of the Universe. I will particularly present the possibility to measure it using the Redshift Space Distortions probe. We will see the necessity to go beyond the linear approximation of the structure formation using 2nd order Lagrangian Perturbation Theory and N-body simulations
Participante: Dr. Sebastien Fromenteau
Institución: Instituto de Ciencias Físicas, UNAM
Fecha: Miércoles, 30 de Mayo de 2018