text: The superfluid phase of neutron matter exists in neutron stars. 
  The superfluidity is described by the BCS model with a realistic nucleon-nucleon interaction potential.
  By increasing the density of nuclear matter above the saturation density, quark matter is formed. It is expected that dense quark matter at low 
  temperatures is a color superconductor.
  In the case of the SU(3) color group, a Bose–Einstein condensate of the quark Cooper pairs carries an open color. To meet the requirement of confinement, 
  a Bose–Einstein condensate of colorless 6-quark states is considered, or the projected BCS theory is used.