$A_n^{(1)}$ affine Toda field theories with integrable boundary conditions revisited

Abstract

Generic classically integrable boundary conditions for the $A_n^{(1)}$ affine Toda field theories (ATFT) are investigated. The present analysis rests primarily on the underlying algebra, defined by the classical version of the reflection equation. We use as a prototype example the first non-trivial model of the hierarchy i.e. the $A_2^{(1)}$ ATFT, however our results may be generalized for any $A_n^{(1)}$ ($n>1$). We assume here two distinct types of boundary conditions called some times soliton preserving (SP), and soliton non-preserving (SNP) associated to two distinct algebras, i.e. the reflection algebra and the ($q$) twisted Yangian respectively. The boundary local integrals of motion are then systematically extracted from the asymptotic expansion of the associated transfer matrix. In the case of SNP boundary conditions we recover previously known results. The other type of boundary conditions (SP), associated to the reflection algebra, are novel in this context and lead to a different set of conserved quantities that depend on free boundary parameters. It also turns out that the number of local integrals of motion for SP boundary conditions is `double' compared to those of the SNP case.

26 pages, Latex. Typos corrected

References in corpus (2)

• The generalized non-linear Schrodinger model on the interval
• (Quantum) twisted Yangians: symmetry, Baxterisation and centralizers

Cited by in corpus (6)

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• Sigma models in the presence of dynamical point-like defects
• Boundary Lax pairs for the $A_n^{(1)}$ Toda field theories
• Jumps and twists in affine Toda field theories
• Scattering matrices in the sl(3) twisted Yangian
• Real Hamiltonian forms of affine Toda field theories: spectral aspects