The great observational progress in cosmology has revealed some very intriguing puzzles, the most important of which are the existence of new mysterious components of the Universe: the dark matter and the dark energy. While a standard model of cosmology — the Lambda cold dark matter (LCDM) paradigm — has emerged, many puzzles are as yet unsolved. Is dark energy really just a cosmological constant (Lambda), or is it something dynamical, perhaps even a clue that Einstein’s general relativity needs modifications at cosmological scales? Is dark matter a new particle beyond the Standard Model, and do its microscopic properties leave any imprint at cosmological or galactic scales (e.g., deep inside galaxy clusters, or in dwarf galaxies)? The nature of dark matter would also have very interesting consequences for the reionization history of the Universe, which is already being constrained by observations of high redshift quasars and galaxies and is expected to be determined in considerable de...
