From recursion operators to Hamiltonian structures. The factorization method

We describe a simple algorithmic method of constructing Hamiltonian structures for nonlinear PDE. Our approach is based on the geometrical theory of nonlinear differential equations and is in a sense inverse to the well-known Magri scheme. As an illustrative example, we take the KdV equation and the Boussinesq equation. Further applications, including construction of previously unknown Hamiltonian structures, are in preparation

The Monge-Ampère equation: Hamiltonian and symplectic structures, recursions, and hierarchies

Using methods of geometry and cohomology developed recently, we study the Monge-Ampère equation, arising as the first nontrivial equation in the associativity equations, or WDVV equations. We describe Hamiltonian and symplectic structures as well as recursion operators for this equation in its orginal form, thus treating the independent variables on an equal footing. Besides this we present nonlocal symmetries and generating functions (cosymmetries)

The D-Boussinesq equation: Hamiltonian and symplectic structures; Noether and inverse Noether operators

Using new methods of analysis of integrable systems,based on a general geometric approach to nonlinear PDE,we discuss the Dispersionless Boussinesq Equation, which is equivalent to the Benney-Lax equation,being a system of equations of hydrodynamical type. The results include: a description of local and nonlocal Hamiltonian and symplectic structures, hierarchies of symmetries, hierarchies of conservation laws, recursion operators for symmetries and generating functions of conservation laws. Highly interesting are the appearences of the Noether and Inverse Noether operators ,leading to multiple infinite hierarchies of these operators as well as recursion operators

Symbolic computations in applied differential geometry

The main aim of this paper is to contribute to the automatic calculations in differential geometry and its applications, with emphasis on the prolongation theory of Estabrook and Wahlquist, and the calculation of invariance groups of exterior differential systems. A large number of worked examples have been included in the text to demonstrate the concrete manipulations in practice. In the appendix, a list of programs discussed in the paper is added

Generalized WDVV equations for F4 pure N=2 Super-Yang-Mills theory

An associative algebra of holomorphic differential forms is constructed associated with pure N=2 Super-Yang-Mills theory for the Lie algebra F4. Existence and associativity of this algebra, combined with the general arguments in the work of Marshakov, Mironov and Morozov, proves that the prepotential of this theory satisfies the generalized WDVV system.Comment: 7 page