Integrable Boundary Conditions and Reflection Matrices for the O(N) Nonlinear Sigma Model

Abstract

We find new integrable boundary conditions, depending on a free parameter $g$, for the O(N) nonlinear $\sigma$ model, which are of nondiagonal type, that is, particles can change their ``flavor'' through scattering off the boundary. These boundary conditions are derived from a microscopic boundary lagrangian, which is used to establish their integrability, and exhibit integrable flows between diagonal boundary conditions investigated earlier. We solve the boundary Yang-Baxter equation, connect these solutions to the boundary conditions, and examine the corresponding integrable flows.

21 pages, 2 figures. v2: References added, typos corrected, few comments added

References in corpus (1)

• Spontaneous symmetry breaking in the gl(N)-NLS hierarchy on the half line

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