A combinatorial approach to integrals of Kahan-Hirota-Kimura   discretizations
  We consider an Ansatz for the study of the existence of formal integrals of motion for Kahan-Hirota-Kimura discretizations. In this context, we give a combinatorial proof of the formula of Celledoni-McLachlan-Owren-Quispel for an integral of motion of the discretization in the case of cubic Hamiltonian systems on symplectic vector spaces and Poisson vector spaces with constant Poisson structure. 
Ren\'e Zander
nlin.SI math-ph math.MP math.NA