2010/09/13 by Alexander V. Mikhailov, Jing Ping Wang, Pavlos Xenitidis
Physics and Astronomy · #nlin.SI
paper · pdf · doi:10.1088/0951-7715/24/7/009
published as Nonlinearity 24:2079--2097, 2011
arxiv created 2010/09/13 · arxiv updated 2015/05/19
In this paper we discuss the concept of cosymmetries and co--recursion operators for difference equations and present a co--recursion operator for the Viallet equation. We also discover a new type of factorisation for the recursion operators of difference equations. This factorisation enables us to give an elegant proof that the recursion operator given in arXiv:1004.5346 is indeed a recursion operator for the Viallet equation. Moreover, we show that this operator is Nijenhuis and thus generates infinitely many commuting local symmetries. This recursion operator and its factorisation into Hamiltonian and symplectic operators can be applied to Yamilov's discretisation of the Krichever-Novikov equation.