Factorial Basis Method for q-Series Applications
Antonio Jiménez-Pastor, Ali Kemal Uncu
TL;DR
This work extends the factorial-basis framework to $q$-series by introducing $\\beta(n)$-factorial bases and product bases, enabling definite-sum representations and holonomic proofs of $q$-identities. The authors develop a compatible-operator theory in the $q$-setting, including $q$-binomial bases and $q$-power bases, and show how to combine bases via product bases to obtain nested sum representations and recurrences for summands. They apply the method to Rogers–Ramanujan-type identities, deriving new representations for bounded generating functions and recovering known results such as the corollary $d_j(a,-q;q)=a^j q^{3j^2+j}(q^3;q^6)_j$, all within a framework amenable to Zeilberger-style automatic proof. A SageMath prototype (pseries_basis) and accompanying resources illustrate practical, automated exploration and discovery of $q$-identities. Overall, the paper provides a computational approach that both proves classical $q$-series results and uncovers new ones, enhancing tools for $q$-combinatorics and partition theory.
Abstract
The Factorial Basis method, initially designed for quasi-triangular, shift-compatible factorial bases, provides solutions to linear recurrence equations in the form of definite-sums. This paper extends the Factorial Basis method to its q-analog, enabling its application in q-calculus. We demonstrate the adaptation of the method to q-sequences and its utility in the realm of q-combinatorics. The extended technique is employed to automatically prove established identities and unveil novel ones, particularly some associated with the Rogers-Ramanujan identities.
