English

The $q$-Borel Sum of Divergent Basic Hypergeometric Series ${}_r\varphi_s(a;b;q,x)$

Classical Analysis and ODEs 2019-03-06 v2

Abstract

We study the divergent basic hypergeometric series which is a qq-analog of divergent hypergeometric series. This series formally satisfies the linear qq-difference equation. In this paper, for that equation, we give an actual solution which admits basic hypergeometric series as a qq-Gevrey asymptotic expansion. Such an actual solution is obtained by using qq-Borel summability, which is a qq-analog of Borel summability. Our result shows a qq-analog of the Stokes phenomenon. Additionally, we show that letting q1q\to1 in our result gives the Borel sum of classical hypergeometric series. The same problem was already considered by Dreyfus, but we note that our result is remarkably different from his one.

Keywords

Cite

@article{arxiv.1806.05375,
  title  = {The $q$-Borel Sum of Divergent Basic Hypergeometric Series ${}_r\varphi_s(a;b;q,x)$},
  author = {Shunya Adachi},
  journal= {arXiv preprint arXiv:1806.05375},
  year   = {2019}
}