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arXiv · 1906.01909

Boundary entropy of integrable perturbed $SU(2)_k$ WZNW

Ivan Kostov·Didina Serban·Dinh-Long Vu
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Abstract

We apply the recently developped analytical methods for computing the boundary entropy, or the g-function, in integrable theories with non-diagonal scattering. We consider the particular case of the current-perturbed $SU(2)_k$ WZNW model with boundary and compute the boundary entropy for a specific boundary condition. The main problem we encounter is that in case of non-diagonal scattering the boundary entropy is infinite. We show that this infinity can be cured by a subtraction. The difference of the boundary entropies in the UV and in the IR limits is finite, and matches the known g-functions for the unperturbed $SU(2)_k$ WZNW model for even values of the level.

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Ivan Kostov, Didina Serban, Dinh-Long Vu. 2019-06-05. Boundary entropy of integrable perturbed $SU(2)_k$ WZNW. https://arxiv.org/abs/1906.01909

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