On the universality of the zero-age luminosity function for open clusters

Differential and integral luminosity functions for 21 open clusters are used to statistically verify the hypothesis of a universal zero-age luminosity function for open clusters. Application of the Pearson and Kolmogorov statistical consistency criteria shows that for very young, young, and middle-aged clusters, the differences in luminosity functions are largely random. This mutual consistency does not contravene the hypothesis that open clusters have a universal zero-age luminosity function.