ISSN 0869-6632 (Print)
ISSN 2542-1905 (Online)

normal forms

Equations with the Fermi–Pasta–Ulam and dislocations nonlinearity

Issue. The class of Fermi–Pasta–Ulam equations and equations describing dislocations are investigated. Being a bright representative of integrable equations, they are of interest both in theoretical constructions and in applied research. Investigation methods. In the present work, a model combining these two equations is considered, and local dynamic properties of solutions are investigated. An important feature of the model is the fact that the infinite set of characteristic numbers of the equation linearized at zero consists of purely imaginary values.

Dynamics of two-component parabolic systems of schrodinger type

Issue. The paper considers the local dynamics of important for applications class of two-component nonlinear systems of parabolic equations. These systems contain a small parameter appearing in the diffusion coefficients and characterizing «closeness» of the initial system of a parabolic type to a hyperbolic one. On quite natural conditions critical cases in the problem about balance state stability are realized to linearized equation coefficients. Innovation.

Asymptotic research of local dynamics of the Cahn–Hilliard family equations

Topic. Dynamics of well-known Cahn–Hilliard nonlinear equation is researched. In a state of balance stability task, critical cases were highlighted and bifurcation phenomena were researched. Aim. To formulate finite-dimensional and special infinite-dimensional equations, which can be represented as normal forms. Method. You can use as standard local dynamics research methods, based on constructing of normal forms on central manifolds, and special infinite-dimensional normalization ones.