NLIE for hole excited states in the sine-Gordon model with two boundaries

We derive a nonlinear integral equation (NLIE) for some bulk excited states of the sine-Gordon model on a finite interval with general integrable boundary interactions, including boundary terms proportional to the first time derivative of the field. We use this NLIE to compute numerically the dimensions of these states as a function of scale, and check the UV and IR limits analytically. We also find further support for the ground-state NLIE by comparison with boundary conformal perturbation theory (BCPT), boundary truncated conformal space approach (BTCSA) and the boundary analogue of the Lüscher formula. Department of Physics, Ewha Womans University, Seoul 120-750, South Korea Theoretical Physics Research Group of the Hungarian Academy of Sciences, Eötvös University, H-1117 Budapest, Pázmány Péter sétány 1/A, Hungary Physics Department, P.O. Box 248046, University of Miami, Coral Gables, FL 33124 USA Institute for Theoretical Physics, Eötvös University, H-1117 Budapest, Pázmány Péter sétány 1/A, Hungary