Möbius Symmetry of Discrete Time Soliton Equations

Abstract

We have proposed, in our previous papers [Y. Narita et al.: J. Phys. Soc. Jpn. 70 (2001) 1246; S. Saito et al.: J. Phys. Soc. Jpn. 70 (2001) 3517], a method to characterize integrable discrete soliton equations. In this paper we generalize the method further and obtain a q-difference Toda equation, from which we can derive various q-difference soliton equations by reductions.