English

Hypergeometric functions of type $BC$ and standard multiplicities

Representation Theory 2023-10-24 v2

Abstract

We study the Heckman-Opdam hypergeometric functions associated to a root system of type BCBC and a multiplicity function which is allowed to assume some non-positive values (a standard multiplicity function). For such functions, we obtain positivity properties and sharp estimates which imply a characterization of the bounded hypergeometric functions. As an application, our results extend known properties of Harish-Chandra's spherical functions on Riemannian symmetric spaces of the non-compact type G/KG/K to spherical functions over homogeneous vector bundles on G/KG/K which are associated to certain small KK-types.

Keywords

Cite

@article{arxiv.2008.00337,
  title  = {Hypergeometric functions of type $BC$ and standard multiplicities},
  author = {E. K. Narayanan and A. Pasquale},
  journal= {arXiv preprint arXiv:2008.00337},
  year   = {2023}
}

Comments

The present paper subsumes and extends the results of the preprint arXiv:1705.00277. With respect to arXiv:2008.00337: Corrected Proposition 3.5. Some computations added in Appendix B

R2 v1 2026-06-23T17:34:38.329Z