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arXiv · 1907.07763

Algebraic Relations Between Partition Functions and the $j$-Function

Alice Lin·Eleanor McSpirit·Adit Vishnu
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Abstract

We obtain identities and relationships between the modular $j$-function, the generating functions for the classical partition function and the Andrews $spt$-function, and two functions related to unimodal sequences and a new partition statistic we call the "signed triangular weight" of a partition. These results follow from the closed formula we obtain for the Hecke action on a distinguished harmonic Maass form $\mathscr{M}(\tau)$ defined by Bringmann in her work on the Andrews $spt$-function. This formula involves a sequence of polynomials in $j(\tau)$, through which we ultimately arrive at expressions for the coefficients of the $j$-function purely in terms of these combinatorial quantities.

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Alice Lin, Eleanor McSpirit, Adit Vishnu. 2019-07-17. Algebraic Relations Between Partition Functions and the $j$-Function. https://doi.org/10.1007/s40993-019-0177-7

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