%0 Journal Article %T Orthogonal polynomials on the unit circle, $q$-Gamma weights, and discrete Painlev¨¦ equations %A Philippe Biane %J Mathematics %D 2009 %I arXiv %X We consider orthogonal polynomials on the unit circle with respect to a weight which is a quotient of $q$-gamma functions. We show that the Verblunsky coefficients of these polynomials satisfy discrete Painlev\'e equations, in a Lax form, which correspond to an $A_3^{(1)}$ surface in Sakai's classification. %U http://arxiv.org/abs/0901.0947v2