Staircase tableaux, the asymmetric exclusion process, and Askey-Wilson polynomials
Staircase tableaux, the asymmetric exclusion process, and Askey-Wilson polynomials
复制标题
楼梯造型、不对称排除过程和 Askey-Wilson 多项式
DOI:
10.1073/pnas.0909915107
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发表时间:
2009
期刊:
影响因子:
--
通讯作者:
L. Williams
中科院分区:
文献类型:
--
作者:
S. Corteel;L. Williams
We introduce some combinatorial objects called staircase tableaux, which have cardinality 4nn !, and connect them to both the asymmetric exclusion process (ASEP) and Askey-Wilson polynomials. The ASEP is a model from statistical mechanics introduced in the late 1960s, which describes a system of interacting particles hopping left and right on a one-dimensional lattice of n sites with open boundaries. It has been cited as a model for traffic flow and translation in protein synthesis. In its most general form, particles may enter and exit at the left with probabilities α and γ, and they may exit and enter at the right with probabilities β and δ. In the bulk, the probability of hopping left is q times the probability of hopping right. Our first result is a formula for the stationary distribution of the ASEP with all parameters general, in terms of staircase tableaux. Our second result is a formula for the moments of (the weight function of) Askey-Wilson polynomials, also in terms of staircase tableaux. Since the 1980s there has been a great deal of work giving combinatorial formulas for moments of classical orthogonal polynomials (e.g. Hermite, Charlier, Laguerre); among these polynomials, the Askey-Wilson polynomials are the most important, because they are at the top of the hierarchy of classical orthogonal polynomials.