Yang-Yang anomaly

The Yang-Yang anomaly provides (Eq. 3):

$C_{V}=VT\left.{\frac {\partial ^{2}p}{\partial T^{2}}}\right\vert _{V}-NT\left.{\frac {\partial ^{2}\mu }{\partial T^{2}}}\right\vert _{V}$

where $C_{V}$ is the heat capacity at constant volume and $\mu$ is the chemical potential. Given that experimentally it is found that $C_{V}$ diverges at the critical temperature this implies that either $\partial ^{2}p/\partial T^{2}$ or $\partial ^{2}\mu /\partial T^{2}$, or both, diverge as $T\rightarrow T_{c}^{-}$. Fisher and Orkoulas showed the both diverge.