Boundary energy and boundary states in integrable quantum field theories
Abstract
We study the groundstate energy of integrable 1 + 1 quantum field theories with boundaries (the genuine Casimir effect). In the scalar case, this is done by introducing a new "Rchannel TBA", where the boundary is represented by a boundary state, and the thermodynamics involves evaluating scalar products of boundary states with all the states of the theory. In the nonscalar, sineGordon case, this is done by generalizing the method of Destri and De Vega. The two approaches are compared. Miscellaneous other results are obtained, in particular formulas for the overall normalization and scalar products of boundary states, exact partition functions for the critical Ising model in a boundary magnetic field, and also results for the energy, excited states and boundary Smatrix of O( n) and minimal models.
 Publication:

Nuclear Physics B
 Pub Date:
 February 1995
 DOI:
 10.1016/05503213(95)00435U
 arXiv:
 arXiv:hepth/9503227
 Bibcode:
 1995NuPhB.453..581L
 Keywords:

 High Energy Physics  Theory
 EPrint:
 3 figures in the separate compressed file, 42 pages