The dark side of cosmology: Dark matter and dark energy

A simple model with only six parameters (the age of the universe, the density of atoms, the density of matter, the amplitude of the initial fluctuations the scale dependance of this amplitude and the epoch of first star formation) fits all of our cosmological data . While simple, this standard model is strange. The model implies that most of the matter in our Galaxy is in the form of "dark matter", a new type of particle not yet detected in the laboratory, and most of the energy in the universe is in the form of "dark energy", energy associated with empty space. Both dark matter and dark energy require extensions to the our current understanding of particle physics or point towards a breakdown of General Relativity on cosmological scales.