A characterization of strict Jacobi-Nijenhuis manifolds through the theory of Lie algebroids

We obtain a characterization of strict Jacobi-Nijenhuis structures using the equivalent notions of generalized Lie bialgebroid and Jacobi bialgebroid.     

Superposition rules, lie theorem, and partial differential equations

A rigorous geometric proof of the Lie theorem on nonlinear superposition rules for solutions of nonautonomous ordinary differential equations is given filling in all the gaps present in the existing literature. The proof is based on an alternative but equivalent definition of a superposition rule: it is considered as a foliation with some suitable properties. The problem of uniqueness of the superposition function is solved, the key point being the codimension of the foliation constructed from the given Lie algebra of vector fields. Finally, as a more convincing argument supporting the use of this alternative definition of superposition rule, it is shown that this definition allows an immediate generalization of the Lie theorem for the case of systems of partial differential equations.     

Time Evolution of Density Operator for Field Damping in Squeezed Bath Calculated by Squeezing Transformation and Entangled State Representation

We find that a squeezing transformation can efficiently simplify the density operator equation of field damping in a squeezed bath. Then the entangled state representation is introduced to solve the simplified equation and the time evolution of density operator, which turns out to be a mixed coherent squeezed state. Work supported by the President Foundation of Chinese Academy of Science and Specialized research fund for the doctorial progress of Higher Education (SRFDP).     

Lie Symmetry Analysis,Bäcklund Transformations and Exact Solutions to (2+1)-Dimensional Burgers' Types of Equations

This paper is concerned with the (2+1)-dimensional Burgers' and heat types of equations. All of the geometic vector fields of the equations are obtained, an optimal system of the equation is presented. Especially, the Bäcklund transformations (BTs) for the Burgers' equations are constructed based on the symmetry. Then, all of the symmetry reductions are provided in terms of the optimal system method, and the exact explicit solutions are investigated by the symmetry reductions and Bäcklund transformations.     

Deviation operator and deviation equations over spaces with affine connections and metrics

The notion of deviation operator over spaces with affine connection (L_n-spaces) is introduced and its applications to deviation equations is considered. On the basis of a deviation identity, by means of sufficient or necessary and sufficient conditions, different deviation equations are obtained and considered. It is shown that the deviation equation for auto-parallel trajectories in L_n-spaces (geodesics in V_n-spaces) allows also other solutions than the well-known solutions for auto-parallel (geodesic) trajectories.