THE SPECTRUM OF BOUNDARY SINE-GORDON THEORY

摘要

We review our recent results on the on-shell description of sine-Gordon model with integrable boundary conditions. We have determined the spectrum of boundary states by closing the boundary bootstrap and found a derivation of Al.B. Zamolodchikov's (unpublished) formulae for the boundary energy and the relation between the Lagrangian (ultraviolet) and bootstrap (infrared) parameters. These results have been checked against numerical finite volume spectra coming from the truncated conformal space approach. We find an entirely consistent picture and strong evidence for the validity of the conjectured spectrum and scattering amplitudes, which together give a complete description of the boundary sine-Gordon theory on the mass shell.