COT3 - Inhomogeneous Cosmology |
Speaker_ |
Celerier, Marie-noelle |
Talk _ |
Is the apparent acceleration of the universe expansion driven by a dark energy-like component or inhomogeneities? |
Abstract _ |
Since its decovery during the late 90's, the dimming of distant SNIa apparent luminosity has been mostly ascribed to the influence of a mysterious dark energy component. Based upon the cosmological ``principle'' hypothesis, this interpretation has given rise to the ``concordance'' model, developed in the context of a Friedmann-Lemaitre cosmology. However, a caveat for this reasoning is that the cosmological ``principle'' derives from a philosophical Copernician assumption and has never been tested. Furthermore, a weakness of its conclusion, e.g., the existence of a negative-pressure fluid or a cosmological constant, is that it would have profound implications for the current theories of physics. This is why we have proposed a more conservative explanation, ascribing the departure of the observed universe from an Einstein-de Sitter model to the influence of inhomogeneities. This idea has been further developed by other authors and enlarged to the reproduction of different cosmological data. We will review here the main proposals which has been made along these lines of though and present some prospects for future developments. |