The Poisson-Dirichlet distribution with parameter is the statistical
distribution of the decreasing rearrangement of the fragments of a random stick-breaking
construction. In this one-parameter convention, also denoted
, take independent
random variables
with probability
density function
on
and put
The decreasing rearrangement has nonnegative
entries summing to 1 almost surely. For
, the variables
have a uniform distribution
on
.