Symmetries of the hypergeometric function \phantom{}_{𝑚}𝐹_{𝑚-1}

Gleizer, Oleg

doi:10.1090/S0002-9947-07-04369-3

Symmetries of the hypergeometric function $\phantom {}_mF_{m-1}$
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Trans. Amer. Math. Soc. 360 (2008), 2547-2580 Request permission

Abstract:

In this paper, we show that the generalized hypergeometric function $\phantom {}_mF_{m-1}$ has a one parameter group of local symmetries, which is a conjugation of a flow of a rational Calogero-Mozer system. We use the symmetry to construct fermionic fields on a complex torus, which have linear-algebraic properties similar to those of the local solutions of the generalized hypergeometric equation. The fields admit a nontrivial action of the quaternions based on the above symmetry. We use the similarity between the linear-algebraic structures to introduce the quaternionic action on the direct sum of the space of solutions of the generalized hypergeometric equation and its dual. As a side product, we construct a “good” basis for the monodromy operators of the generalized hypergeometric equation inspired by the study of multiple flag varieties with finitely many orbits of the diagonal action of the general linear group by Magyar, Weyman, and Zelevinsky. As an example of computational effectiveness of the basis, we give a proof of the existence of the monodromy invariant hermitian form on the space of solutions of the generalized hypergeometric equation (in the case of real local exponents) different from the proofs of Beukers and Heckman and of Haraoka. As another side product, we prove an elliptic generalization of Cauchy identity.

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