English

Transformations and summations for bilateral basic hypergeometric series

Classical Analysis and ODEs 2026-02-27 v2

Abstract

We review and derive transformation and summation formulas for bilateral basic hypergeometric series. Our study focuses on consequences of certain bilateral extensions of two important results by Bailey, namely a transformation for very-well-poised 8W7_8W_7 series in terms of two balanced 4ϕ3_4\phi_3 series, and a transformation connecting three 8W7_8W_7 series. Two rather recently discovered transformations of bilateral basic very-well-poised 8Ψ8{}_8\Psi_8, one by Zhang and Zhang, the other by Wei and Yu, serve as the starting point of our investigations. From these transformations we work out interesting special cases that were not considered before, including explicit bilateral quadratic and cubic summations. We further explicitly record noteworthy lower-level transformations derived by taking suitable limits and deduce more transformations by exploiting the symmetry of the parameters in the series.

Keywords

Cite

@article{arxiv.2504.21782,
  title  = {Transformations and summations for bilateral basic hypergeometric series},
  author = {Howard S. Cohl and Michael J. Schlosser},
  journal= {arXiv preprint arXiv:2504.21782},
  year   = {2026}
}

Comments

Update with major changes including removing the Appendix and including several nonterminating summations