If the roots do coalesce and pinch the positive real axis, then then density n can be discontinuous, as in a first order phase transition, or a higher derivative \pzjp/\pznj can be discont...If the roots do coalesce and pinch the positive real axis, then then density n can be discontinuous, as in a first order phase transition, or a higher derivative \pzjp/\pznj can be discontinuous or divergent, as in a second order phase transition. n=z\pz\pzz(p\kT)={1v\ns0⋅z1+z if |z|<11v\ns0⋅[z1+z+1] if |z|>1.
