arXiv subjects

Yunbo Zeng

Publications and source records attributed to Yunbo Zeng.

44 records · Page 3Linked to original sources

arXiv2001

Two binary Darboux transformations for the KdV hierarchy with self-consistent sources

Two binary (integral type) Darboux transformations for the KdV hierarchy with self-consistent sources are proposed. In contrast with the Darboux transformation for the KdV hierarchy, one of the two binary Darboux transformations provides non auto-Bäcklund transformation between two n-th KdV equations with self-consistent sources with different degrees. The formula for the m-times repeated binary Darboux transformations are presented. This enables us to construct the N-soliton solution for the KdV hierarchy with self-consistent sources.

nlin.SI↗

arXiv2000

Deriving N-soliton solutions via constrained flows

The soliton equations can be factorized by two commuting x- and t-constrained flows. We propose a method to derive N-soliton solutions of soliton equations directly from the x- and t-constrained flows.

nlin.SI↗

arXiv2000

A new method to introduce additional separated variables for high-order binary constrained flows

Degrees of freedom for high-order binary constrained flows of soliton equations admitting $2\times 2$ Lax matrices are $2N+k_0$. It is known that $N+k_0$ pairs of canonical separated variables for their separation of variables can be introduced directly via their Lax matrices. In present paper we propose a new method to introduce the additional $N$ pairs of canonical separated variables and $N$ additional separated equations. The Jacobi inversion problems for high-order binary constrained flows and for soliton equations are also established. This new method can be applied to all high-order binary constrained flows admitting $2\times 2$ Lax matrices.

nlin.SI↗

arXiv1999

Separation of variables for soliton equations via their binary constrained flows

Binary constrained flows of soliton equations admitting $2\times 2$ Lax matrices have 2N degrees of freedom, which is twice as many as degrees of freedom in the case of mono-constrained flows. For their separation of variables only N pairs of canonical separated variables can be introduced via their Lax matrices by using the normal method. A new method to introduce the other N pairs of canonical separated variables and additional separated equations is proposed. The Jacobi inversion problems for binary constrained flows are established. Finally, the factorization of soliton equations by two commuting binary constrained flows and the separability of binary constrained flows enable us to construct the Jacobi inversion problems for some soliton hierarchies.

solv-int↗

arXiv1999

Families of quai-bi-Hamiltonian systems and separability

It is shown how to construct an infinite number of families of quasi-bi-Hamiltonian (QBH) systems by means of the constrained flows of soliton equations. Three explicit QBH structures are presented for the first three families of the constrained flows. The Nijenhuis coordinates defined by the Nijenhuis tensor for the corresponding families of QBH systems are proved to be exactly the same as the separated variables introduced by means of the Lax matrices for the constrained flows.

solv-int↗

arXiv1998

The relation between the Toda hierarchy and the KdV hierarchy

Under three relations connecting the field variables of Toda flows and that of KdV flows, we present three new sequences of combination of the equations in the Toda hierarchy which have the KdV hierarchy as a continuous limit. The relation between the Poisson structures of the KdV hierarchy and the Toda hierarchy in continuous limit is also studied.

solv-int↗

arXiv1995

The separability and dynamical $r$-matrix for the constrained flows of Jaulent-Miodek hierarchy

We show here the separability of Hamilton-Jacobi equation for a hierarchy of integrable Hamiltonian systems obtained from the constrained flows of the Jaulent-Miodek hierarchy. The classical Poisson structure for these Hamiltonian systems is constructed. The associated $r$-matrices depend not only on the spectral parameters, but also on the dynamical variables and, for consistency, have to obey the classical Yang-Baxter equations of dynamical type. Some new solutions of classical dynamical Yang-Baxter equations are presented. Thus these integrable systems provide examples both for the dynamical $r$-matrix and for the separable Hamiltonian system not having a natural Hamiltonian form.

solv-int↗

arXiv1995

Classical Poisson structures and r-matrices from constrained flows

We construct the classical Poisson structure and $r$-matrix for some finite dimensional integrable Hamiltonian systems obtained by constraining the flows of soliton equations in a certain way. This approach allows one to produce new kinds of classical, dynamical Yang-Baxter structures. To illustrate the method we present the $r$-matrices associated with the constrained flows of the Kaup-Newell, KdV, AKNS, WKI and TG hierarchies, all generated by a 2-dimensional eigenvalue problem. Some of the obtained $r$-matrices depend only on the spectral parameters, but others depend also on the dynamical variables. For consistency they have to obey a classical Yang-Baxter-type equation, possibly with dynamical extra terms.

solv-int↗