Sign Changes of Coefficients of Powers of the Infinite Borwein Product

Autor: Wang, Liuquan
Rok vydání: 2021
Předmět:
Druh dokumentu: Working Paper
Popis: We denote by $c_t^{(m)}(n)$ the coefficient of $q^n$ in the series expansion of $(q;q)_\infty^m(q^t;q^t)_\infty^{-m}$, which is the $m$-th power of the infinite Borwein product. Let $t$ and $m$ be positive integers with $m(t-1)\leq 24$. We provide asymptotic formula for $c_t^{(m)}(n)$, and give characterizations of $n$ for which $c_t^{(m)}(n)$ is positive, negative or zero. We show that $c_t^{(m)}(n)$ is ultimately periodic in sign and conjecture that this is still true for other positive integer values of $t$ and $m$. Furthermore, we confirm this conjecture in the cases $(t,m)=(2,m),(p,1),(p,3)$ for arbitrary positive integer $m$ and prime $p$.
Comment: 28 pages (including an Appendix with 5 pages). This paper has been rewritten after its first version (v1) with a different title. We found that the results in v1 can be generalized and thus rewrote it in v2. Minor changes will be made after v2. Please do not cite v1
Databáze: arXiv