Structure formation in the Universe

Cosmological concordance model. Credit: Hubble Space Telescope Science Institute

Studying the structuration of the Universe consists in studying how galaxies, galaxy clusters, stars and planets form and evolve. The starting point of the structuration of the Universe is well known: the tiny inhomogeneities in the diffuse cosmological background, as observed by WMAP and more recently by Planck. The theoretical framework of the studies is the so-called “cosmological concordance model”, with its two components: dark energy and dark matter. Then, observing the structuration of the Universe is also a way to test the cosmological model. Structuration of the Universe and observational cosmology are strongly interleaved. The studies are made from multi-wavelenghts observations and multi-scales numerical simulations.


Last update : 12/10 2013 (548)

The study of the large-scale structures of the Universe has developed dramatically over the past two decades, since the discovery of temperature fluctuations in the cosmic microwave background by the COBE satellite team in 1992 (2006 Nobel Physics Prize). This has made our knowledge of the initial conditions of the Universe accurate enough to consider studying its dynamic evolution over the 13 to 14 billion years of its existence. In the course of this evolution, small primordial density fluctuations grew under the ... More »
Observational Cosmology has reached an important turning point. After years of seeking the parameters that govern the evolution of the Universe, there seems to be increasing consensus in acknowledging the dominant influence of dark matter on baryons and that of dark energy on dark matter. Paradoxically, the behaviour of the two “dark” components that make up 95% of the energy content of the Universe is easy to model (dark matter is nondissipative and subject only to gravity, while dark energy acts as an ... More »
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