  At high nuclear density and small temperature, due to the asymptotic freedom
property of Quantum ChromoDynamics and to the existence of an attractive
channel in the color interaction, diquark condensates might be formed. Since
these condensates break the color gauge symmetry, this phenomenon has the name
of color superconductivity. In the last few years this has become a very active
field of research. While a direct experimental test is still missing, color
superconductivity might have implications in astrophysics because for some
compact stars, e.g. pulsars, the baryon densities necessary for color
superconductivity can probably be reached.
