"The Abnormally Weighting Energy Hypothesis: the Missing Link between Dark Matter and Dark Energy" par Jean-Michel Alimi (Meudon)

Thursday 29 Jan 2009, 15:00 → 16:00 Europe/Paris

salle 9 (LPSC)

We generalize tensor-scalar theories of gravitation by the introduction of an abnormally weighting type of energy. This theory of non-universal coupling tensor-scalar gravity is based on a relaxation of the weak equivalence principle that is now restricted to ordinary visible matter only. As a consequence, the convergence mechanism toward general relativity is modified and produces naturally cosmic acceleration as an inescapable gravitational feedback induced by the mass-variation of some invisible sector. The cosmological implications of this new theoretical framework are studied. From the Hubble diagram cosmological test alone, this theory provides an estimation of the amount of baryons and dark matter in the Universe that is consistent with the independent cosmological tests of Cosmic Microwave Background (CMB) and Big Bang Nucleosynthesis (BBN). Cosmic coincidence is naturally achieved from a natural assumption on the amplitude of the scalar coupling strength. Finally, from the adequacy to supernovae data, we derive a new intriguing relation between the space-time dependancies of the gravitational coupling and the dark matter mass, providing an example of crucial constraint on microphysics from cosmology. This glimpses at a tempting new symmetry between the visible and invisible sectors, namely that the scalar charges of visible and invisible matter are exactly opposite. Ref: (arXiv:0804.4100) JCAP Issue 09, pp. 014 (2008), (arXiv:astro-ph/0702478) Phys. Rev. D 75, 123007 (2007).