Fabio Fontanot (INAF - OATS)

"Semi-analytic Galaxy Formation in Dark Energy Cosmologies"

Giovedì 24 ottobre 2013 ore 11:30
Villa Bazzoni (via Bazzoni, 2)

ABSTRACT:
We study the implications of different dark energy cosmologies by coupling high-resolution numerical simulations with updated semi-analytic modeling (SAM) of galaxy formation and evolution. We consider both Early Dark Energy (EDE) models (characterized by a non-vanishing high-redshift contribution of dark energy) and modifications of the equations of general relativity in the form of f(R)-gravity models (which imply the existence of a ‘fifth-force’). We compare the SAM predicted galaxy properties in these cosmologies with the corresponding quantities obtained for a LCDM universe run on the same initial conditions. We also compare all results with a reference set of theoretical predictions obtained with alternative SAMs applied to the same LCDM simulation, and we show that the modifications in galaxy properties induced by both EDE and MG cosmologies are of the same order of magnitude as intra-SAM variations for a standard LCDM realization. However, when independent information on the underlying properties of host dark matter haloes is combined with galaxy properties, like considering galaxy bias or pairwise velocity distributions, it is possible to disentagle between the different scenarios: therefore the SAM predictions may still provide important clues on the expansion history and the equation-of-state evolution.