size-dependence of stickiness parameters corresponds to model IV. []{data-label="fig3"}](Fig3a.eps "fig:"){height="9.0cm" width="7.5cm"} ![Behavior of the energy equation of state within our perturbative scheme. In all cases the quantity $\beta P v_0$ is plotted against the packing fraction $\eta$. In clockwise order, the first curve (left, top) reports a comparison of the perturbative versus the ‘exact’ BMCSL solution in the equation of state for polydisperse HS ($\tau=+\infty$). The other curves report the perturbative solution for the energy equation of state within the PY approximation for SHS Baxter model. Results are depicted for three values of temperature $\tau=0.15> \tau_c$, $\tau=0.1185\sim
\tau_c$ and $\tau=0.1<\tau_c$ and for different degrees of polydispersity. The choice for the size-dependence of stickiness parameters corresponds to model IV. []{data-label="fig3"}](Fig3b.eps "fig:"){height="9.0cm" width="7.5cm"}\
1.5cm ![Behavior of the energy equation of state within our perturbative scheme. In all cases the quantity $\beta P v_0$ is plotted against the packing fraction $\eta$. In clockwise order, the first curve (left, top) reports a comparison of the perturbative versus the ‘exact’ BMCSL solution in the equation of state for polydisperse HS ($\tau=+\infty$). The other curves report the perturbative solution for the energy equation of state within the PY approximation for SHS Baxter model. Results are depicted 