Constructing discrete Painlevé equations: from E8(1) to A1(1) and back. Issue 4 (2nd October 2019)

• Record Type: Journal Article
• Authors: Ramani, A.; Grammaticos, B.; Willox, R.; Tamizhmani, T.
• Is Part Of: Journal of nonlinear mathematical physics. Volume 26:Issue 4(2019)
• Page Start: 520
• Page End: 535
• Publication Date: 2019-10-02
• Subjects: discrete Painlevé equations -- affine Weyl groups -- restoration method; 02.30.Ik -- 05.45.Yv; Nonlinear theories -- Periodicals; Mathematical physics -- Periodicals; 515.252
• DOI: 10.1080/14029251.2019.1640462
• Languages: English
• ISSNs: 1402-9251

Abstract

Abstract : The 'restoration method' is a novel method we recently introduced for systematically deriving discrete Painlevé equations. In this method we start from a given Painlevé equation, typically with symmetry, obtain its autonomous limit and construct all possible QRT-canonical forms of mappings that are equivalent to it by homographic transformations. Discrete Painlevé equations are then obtained by deautonomising the various mappings thus obtained. We apply the restoration method to two challenging examples, one of which does not lead to a QRT mapping at the autonomous limit but we verify that even in that case our method is indeed still applicable. For one of the equations we derive we also show how, starting from a form where the independent variable advances one step at a time, we can obtain versions that correspond to multiple-step evolutions.