Journal of Nonlinear Mathematical Physics

We consider the Hamiltonian system which is invariant under locally Hamiltonian (non-Poissonian) action of torus. We show that when a certain set of conditions is satisfied the majority of motions in a sufficiently small neighbourhood of system's relative equilibrium are quasi-periodic and cover coisotropic...

New concepts of economics such as an average demand matrix of society, strategy of a firm and consumer behaviour, and others are introduced. We give sufficient conditions for technological mapping under which there exist both the Walras equlibrium state and optimal Walras equilibrium one. We obtain the...

It is shown that eigenvectors of the recursion operator L with the eigenvalue i and the inverse of the recursion operator Li L-i for the coupled KdV hierarchy (CKdVH) can be obtained in terms of squared eigenfunctions of the associated linear problem. The symmetry structure and corresponding infinite...

A q-deformation of the dressing operator introduced by Sato is suggested. It is shown that it produces q-deformation of known integrable heirarchies, with the infinite number of conservation laws. A modification introduced by Kupershmidt when incorporated leads to both modified and deformed integrable...

A symmetry constraint for the MKdV integrable hierarchy is presented by binary nonlinearization. The spatial and temporal parts of the Lax pairs and adjoint Lax pairs of MKdV equations are all constrained as finite-dimensional Liouville integrable Hamiltonian systems, whose integrals of motion are explicitly...