Cosmology News & Events

An extra curricular course on "General Relativity, Cosmology and Black Holes" will run throughout the second semester 2011/12. Only basic knowledge of special relativity and Newtonian gravity will be assumed. By default, sessions will take place every friday at 14H00 in the GAP room. Some lecture notes will be handed out and exercises will be set in every session and solved in the following one.

How do we know that the Universe is expanding faster and faster ? What are the fundamental constituents of the Universe ? Why are dark matter and dark energy relevant to the dynamics of the Universe? What is the information imprinted on the cosmic microwave background ? What is the origin of the large scale structure of the Universe?

Abstract: Evidence for an accelerated expansion of the universe has been provided ten years ago by the Hubble diagram of distant type Ia supernovae. This represents one of the major modern revolutions for fundamental physics and cosmology. It is yet unclear whether the explanation of the fact that gravity becomes repulsive on large scales should be found within general relativity or within a new theory of gravitation. Existing evidences for this acceleration all come from astrophysical observations. In this seminar I will critically examine the present situation of the astrophysical observations and the possible limitation in their interpretation. The main various observational probes will be presented and discussed. I will show that, even when scrutinized with skeptical eyes, the evidence for an accelerating universe is rather robust. Investigation of its very origin appears as the most fascinating challenge of modern physics.