Note: An exact scaling relation for truncatable free energies of polydisperse hard-sphere mixtures.

A theoretical model for polydisperse systems of hard spheres is said to be truncatable when the excess free energy depends on the size distribution through a finite number K of moments. This Note proves an exact scaling relation for truncatable free energies, which allows to reduce the effective degrees of freedom to K - 2 independent combinations of the moments. [ABSTRACT FROM AUTHOR]