Moments of random integer partitions
Yu. V. Yakubovich Saint Petersburg State University
Abstract:
We study the limiting behaviour of the
$p$th moment, that is the sum of
$p$th powers of parts in a partition of a positive integer
$n$ which is taken uniformly among all partitions of
$n$, as
$n\to\infty$ and
$p\in\mathbb{R}$ is fixed. We prove that after an appropriate centring and scaling, for
$p\ge 1/2$ (
$p\ne 1$) the limit distribution is Gaussian, while for
$p<1/2$ the limit is some infinitely divisible distribution, depending on
$p$, which we describe explicitly. In particular, for
$p=0$ this is the Gumbel distribution, which is well known, and for
$p=-1$ the limiting distribution is connected to the Jacobi theta function.
Key words and phrases:
random integer partition, uniform measure on integer partitions, moments of integer partition, limit theorem, Jacobi theta distribution. Received: 25.09.2023