On partitions with bounded largest part and fixed integral GBG-rank modulo primes
Alexander Berkovich, Aritram Dhar
TL;DR
The paper studies partitions with bounded largest part under fixed integral GBG-rank modulo a prime $t$ by employing the Littlewood decomposition into a $t$-core and a $t$-quotient. It provides new generating function formulas for unrestricted partitions, self-conjugate partitions, and partitions with parts repeated no more than $t-1$ times, proving four main theorems that unify these cases under a single combinatorial framework. The results include explicit $q$-product expressions and extensions to GBG-rank values of the form $k\omega_t^j$, offering a direct combinatorial approach to prior $q$-series prompts and yielding new, elegant generating-function identities. The methods illuminate the structure of GBG-rank modulo primes via rim-hook removals and the $t$-core/$t$-quotient decomposition, with potential implications for further refinements and related partition statistics.
Abstract
In 2009, Berkovich and Garvan introduced a new partition statistic called the GBG-rank modulo $t$ which is a generalization of the well-known BG-rank. In this paper, we use the Littlewood decomposition of partitions to study partitions with bounded largest part and fixed integral value of GBG-rank modulo primes. As a consequence, we obtain new elegant generating function formulas for unrestricted partitions, self-conjugate partitions, and partitions whose parts repeat a finite number of times.
