N-Fold Darboux transformation of the discrete Ragnisco-Tu system

In this paper, based on gauge transformation of Lax pairs, we construct an N-fold Darboux transformation for the discrete Ragnisco-Tu equation which is a typical member in the Ragnisco-Tu hierarchy. By using the N-fold Darboux transformation, new multi-soliton solutions of the discrete Ragnisco-Tu equation can be directly constructed starting from a seed solution.