Three $q$-Painlevé equations with affine Weyl group symmetry of type $E_7^{(1)}$

Abstract

Three $q$-Painlevé type equations are derived through degenerations of the $q$-Painlevé equation with affine Weyl group symmetry of type $q$-$E_8^{(1)}$. The three $q$-Painlevé type equations are associated with different realizations of the same symmetry/surface type $q$-$E_7^{(1)}$/$q$-$A_1^{(1)}$. We give three representations of affine Weyl group actions of type $q$-$E_7^{(1)}$, and relations among them. The three $q$-$E_7^{(1)}$ equations are also derived from the three representations respectively.

15 pages, 4 figures