One-point functions in perturbed boundary conformal field theories

Abstract

We consider the one-point functions of bulk and boundary fields in the scaling Lee-Yang model for various combinations of bulk and boundary perturbations. The one-point functions of the bulk fields are analysed using the truncated conformal space approach and the form-factor expansion. Good agreement is found between the results of the two methods, though we find that the expression for the general boundary state given by Ghoshal and Zamolodchikov has to be corrected slightly. For the boundary fields we use thermodynamic Bethe ansatz equations to find exact expressions for the strip and semi-infinite cylinder geometries. We also find a novel off-critical identity between the cylinder partition functions of models with differing boundary conditions, and use this to investigate the regions of boundary-induced instability exhibited by the model on a finite strip.Comment: Latex, 34 pages, 16 figure

Dynamical response functions in the quantum Ising chain with a boundary

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“…In the gapless case this is readily accomplished by boundary conformal field theory 22,23 , while the gapful case is as usual more involved. One successful approach has been the extension of the truncated conformal space approach 24 to systems with boundary 25,26 . The method we will follow in the present work is the extension of the form factor bootstrap approach to boundary integrable field theories 27,28,29,30,31 .…”

Defects and boundary RG flows in ℂ / ℤ d $$ \mathbb{C}/{\mathbb{Z}}_d $$

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“…The behavior of boundary degrees of freedom under renormalization group (RG) flow represents a problem in both string theory and condensed matter physics that is not fully understood (see [1][2][3][4] and references therein). A new approach consists of utilizing defects to bring the RG flow from the bulk to the boundary.…”

Exactly solvable model of the two-dimensional electrical double layer

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