The Music of the Big Bang by Amedeo Balbi

This led to a giant leap in our understanding of the Universe, but the investigation is not over yet. Only lately, has this amazing cosmic sound been unveiled by such experiments as BOOMERANG and MAXIMA and, more recently, by the WMAP satellite. Most cosmological information is encoded in the cosmic background radiation by acoustic oscillations in the dense plasma that filled the primordial Universe: a 'music' of the big bang, which cosmologists have long been trying to reconstruct and analyze, in order to distinguish different cosmological models, much like one can distinguish different musical instruments by their timbre and overtones. Two Nobel Prizes in Physics have already been awarded for research on the cosmic background radiation: one in 1978 to Arno Penzias and Robert Wilson, who first discovered it, the other in 2006, to George Smoot and John Mather, for the results of the COBE satellite. It was serendipitously discovered in 1964, and thoroughly investigated in the last four decades by a large number of experiments. However, the method could be a valuable complementary cosmological tool, and give important insights on the dynamics of dark energy, not obtainable using other probes.The cosmic microwave background radiation is the afterglow of the big bang: a tenuous signal, more than 13 billion years old, which carries the answers to many of the questions about the nature of our Universe. We find that, because of parameter degeneracies, and the inherent technical difficulties involved in this kind of observations, the uncertainties on parameter reconstruction can be rather large unless strong external priors are assumed. We perform a Fisher matrix analysis and discuss the prospects for constraining the parameters of these models and for discriminating among competing candidates.

We investigate the evolution of cosmological redshift from a variety of dark energy models, and compare it with simulated data. This would open a new window to explore the physical mechanism responsible for the current acceleration of the Universe.

quasar Lyman alpha absorption lines) that might be directly observed by future ultrastable, high-resolution spectrographs (such as the COsmic Dynamics Experiment) coupled to extremely large telescopes (such as the European Southern Observatory's Extremely Large Telescope). more The variation of the expansion rate of the Universe with time produces an evolution in the cosmological redshift of distant sources (e.g. The variation of the expansion rate of the Universe with time produces an evolution in the cosmol.

The Music of the Big Bang by Amedeo Balbi