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Centro de Astrofísica da Universidade do Porto

A new signature of primordial non-Gaussianities from the abundance of galaxy clusters

A. M. M. Trindade, P. P. Avelino, P. T. P. Viana

Abstract
The evolution with time of the abundance of galaxy clusters is very sensitive to the statistical properties of the primordial density perturbations. It can thus be used to probe small deviations from Gaussianity in the initial conditions. The characterization of such deviations would help distinguish between different inflationary scenarios, and provide us with information on physical processes which took place in the early Universe.We have found that when the information contained in the galaxy cluster counts is used to reconstruct the dark energy equation of state as a function of redshift, assuming erroneously that no primordial non-Gaussianities exist, an apparent evolution with time in the effective dark energy equation of state arises, characterized by the appearance of a clear discontinuity.

Keywords
dark energy – large-scale structure of Universe

Monthly Notices of the Royal Astronomical Society
Volume 424, Page 1442
August 2012

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