Piero Madau
Lick Obs., Univ. California Obs. (UCO) (Santa Cruz, California, Etats-Unis d'Amérique)
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
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| « The Dark and Light Side of Galaxy Formation » |
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Piero Madau |
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In recent years, precision measurements across cosmic time have led to a widely accepted cosmological paradigm for galaxy assembly and evolution, the cold dark matter (?CDM) model. Within this theory, galaxies form "bottom-up," with low-mass objects ("halos") collapsing earlier and merging to form larger and larger systems over time. Ordinary matter follows the dynamics dictated by the dominant dark matter until radiative, hydrodynamic, and star-formation processes take over. Although ?CDM has had great success in explaining the observed large scale distribution of mass in the universe, the nature of the dark matter particle is best tested on small scales, where its physical characteristics manifest themselves by modifying the structure of galaxy halos and their lumpiness. It is on these scale that detailed comparisons between observations and theory have revealed several discrepancies and challenged our understanding of the mapping between dark matter halos and their baryonic components. In this talk I will review some of the triumphs and tribulations of the theory. While the latter may indicate the need for more complex physics in the dark sector itself, emerging evidence suggests that a poor understanding of the baryonic processes involved in galaxy formation may be at the origin of these controversies.
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vendredi 6 mars 2015 - 11:00 Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |