Effective Field Theory Power Counting at Finite Density
  Effective field theory is applied to finite-density systems with an unnaturally large scattering length, such as neutron matter. A new organizational scheme is identified and connected with an expansion in inverse powers of the number of space-time dimensions. This power counting allows for analytic calculations in many-body systems and reproduces the hole-line expansion of traditional nuclear physics. 
James V. Steele