  According to many phenomenological and theoretical studies the distribution
of family name frequencies in a population can be asymptotically described by a
power law. We show that the Galton-Watson process corresponding to the dynamics
of a growing population can be represented in Hilbert space, and its time
evolution may be analyzed by renormalization group techniques, thus explaining
the origin of the power law and establishing the connection between its
exponent and the ratio between the population growth and the name production
rates.
