Discrete Nonlinear Schrodinger Equations with arbitrarily high order   nonlinearities
  A class of discrete nonlinear Schrodinger equations with arbitrarily high order nonlinearities is introduced. These equations are derived from the same Hamiltonian using different Poisson brackets and include as particular cases the saturable discrete nonlinear Schrodinger equation and the Ablowitz-Ladik equation. As a common property, these equations possess three kinds of exact analytical stationary solutions for which the Peierls-Nabarro barrier is zero. Several properties of these solutions, including stability, discrete breathers and moving solutions, are investigated. 
Avinash Khare, Kim {\O}. Rasmussen, Mario Salerno, Mogens R.   Samuelsen, Avadh Saxena