Alain Blanchard
Observatoire MIDI-Pyrénées, France

Abstract
The Hubble diagram of SN has been interpreted as the evidence for the acceleration of the expansion and consequently the presence of a new unknown component of the universe, dominating its density: the dark energy.
Although current data are consistent with dark energy we have little direct evidence for its actual presence. In addition properties of high redshift clusters are indicative of an Einstein de Sitter Universe, i.e. without dark energy. I will therefore examine the concordance model with a critical point of view and discuss whether viable alternatives exist.

2008 January 23, 13:30

IA/U.Porto
Centro de Astrofísica da Universidade do Porto (Auditorium)
Rua das Estrelas, 4150-762 Porto