text: 1 
  ) 
  
  ∞ 
  W 
  ( 
  
  0.6 
  / 
  ) 
  c 
  
  In Fig 9 we plot ∆W (ωc) as a function of ωc. We see 
  the same behavior as in the BCSI model in a clean limit 
  – ∆W (ωc) is positive at small frequencies, crosses zero 
  at some ωc, passes through a deep minimum at a larger 
  frequency, and eventually saturates at a negative value at 
  the largest wc. However, in distinction to BCSI model, 
  ∆W (ωc) keeps varying with ωc up a much larger scale 
  and saturates only at around 0.8eV . In between the dip 
  at 0.1eV and 0.8eV , the behavior of the optical integral is 
  predominantly determined by the variation of the cut-oﬀ 
  term ∆f (ωc) as evidenced by a close similarity between 
  the behavior of the actual ∆W and ∆W in the absence 
  
  ω 
  W 
  ( 
  
  0.2 
  
  0 
  
  FIG. 8: Evolution of the optical integrals in the EB model. 
  Note that W (0) has a non zero value at T = 0 in the NS 
  because the self-energy at small frequencies is purely real and 
  linear in ω, hence the polarization bubble Π(0) 
  = 0, as in an 
  ideal Fermi gas. Parameters are the same as in ﬁg. 7 