(Non)-Abelian gauge field theories of the Fermi gas. Neutron-quark stars

It is indicated that the ground state of Fermi systems with (non)-Abelian gauge interactions has a well defined quantum theory devoid of infrared divergences and mass singularities. This is exploited to develop a systematic quantum theory of the quark gas. The equation of state of the quark gas is evaluated up to second order in the Gell-Mann-Low charge αsub(S)(μ). The analysis based on neutron matter models suggest that the matter in the neutron stars can be in the quark phase provided the color interaction is 'moderately' strong i.e. αsub(S) (3 GeV) <approximately 0.3. (Auth.)