Symmetry, Integrability and Geometry: Methods and Applications (SIGMA)

SIGMA 7 (2011), 119, 17 pages      arXiv:1106.1835

A System of Multivariable Krawtchouk Polynomials and a Probabilistic Application

F. Alberto Grünbaum a and Mizan Rahman b
a) Department of Mathematics, University of California, Berkeley, CA 94720, USA
b) Department of Mathematics and Statistics, Carleton University, Ottawa, ONT, Canada, K1S 5B6

Received June 10, 2011, in final form December 19, 2011; Published online December 27, 2011

The one variable Krawtchouk polynomials, a special case of the 2F1 function did appear in the spectral representation of the transition kernel for a Markov chain studied a long time ago by M. Hoare and M. Rahman. A multivariable extension of this Markov chain was considered in a later paper by these authors where a certain two variable extension of the F1 Appel function shows up in the spectral analysis of the corresponding transition kernel. Independently of any probabilistic consideration a certain multivariable version of the Gelfand-Aomoto hypergeometric function was considered in papers by H. Mizukawa and H. Tanaka. These authors and others such as P. Iliev and P. Tertwilliger treat the two-dimensional version of the Hoare-Rahman work from a Lie-theoretic point of view. P. Iliev then treats the general n-dimensional case. All of these authors proved several properties of these functions. Here we show that these functions play a crucial role in the spectral analysis of the transition kernel that comes from pushing the work of Hoare-Rahman to the multivariable case. The methods employed here to prove this as well as several properties of these functions are completely different to those used by the authors mentioned above.

Key words: multivariable Krawtchouk polynomials; Gelfand-Aomoto hypergeometric functions; cumulative Bernoulli trial; poker dice.

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