S. Skorik

Boundary energy and boundary states in integrable quantum field theories

Abstract We study the ground-state 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 “R-channel 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 non-scalar, sine-Gordon 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 S -matrix of O ( n ) and minimal models.

The boundary sine-Gordon theory: Classical and semi-classical analysis

We consider the sine-Gordon model on a half-line, with an additional potential term of the form −M cos[12β(ϕ − ϕ0)] at the boundary. We compute the classical time delay for general values of M, β and ϕ0 using τ-function methods and show that in the classical limit the method of images still works, despite the non-linearity of the problem. We also perform a semi-classical analysis, and find agreement with the exact quantum S-matrix conjectured by Ghoshal and Zamolodchikov.We consider the sine-Gordon model on a half-line, with an additional potential term of the form

Boundary bound states and boundary bootstrap in the sine-Gordon model with Dirichlet boundary conditions

-M\cos{\beta\over 2}(\varphi-\varphi_0)

Form factors approach to current correlations in one-dimensional systems with impurities

at the boundary. We compute the classical time delay for general values of

Self-similar potentials and theq-oscillator algebra at roots of unity

M

On the non-relativistic limit of the quantum sine-Gordon model with integrable boundary condition

,

Time correlations in 1D quantum impurity problems

\beta

On the spectra of hyperelliptic potentials

and

Solution of the Thirring model with imaginary mass and massless scattering

\varphi_0

Surface excitations and surface energy of the antiferromagnetic XXZ chain by the Bethe ansatz approach

using