A PRECISE DETERMINATION OF THE EXPANSION HISTORY OF THE UNIVERSE UP TO z similar to 2

作者：Jimenez Raul^*

来源：Romanian Journal of Physics, 2012, 57(5-6): 863-872.

• Cosmology
• dark energy

I present some recent results on efforts to constraint the variation of dark energy as a function of redshift. In particular I concentrate on observational determinations of the expansion history H(z). I also review a formalism that constructs an effective theory of accelerated expansion with a well defined cut-off. This in turn allows to construct the Lagrangian of accelerated expansion. This is done in this paper. I show how the shape of the dark energy potential can be recovered non parametrically using this formalism. This reconstruction can also be used in other approaches followed in the literature (e.g., the reconstruction of the redshift evolution of the dark energy equation of state w(z)). Using observations of passively evolving galaxies I derive constraints on the dark energy potential shape in the redshift range 0.1 %26lt; z %26lt; 1.8. It is shown that at the 1 sigma level the potential is consistent with being constant at the few % level. This is the first time that such accuracy has been achieved, opening the possibility to unveil the symmetries underlying accelerated expansion.

• 出版日期2012