Approaching the self-dual point of the sinh-Gordon model

DOI10.1007/JHEP01(2021)014zbMATH Open1459.81118arXiv2007.00154MaRDI QIDQ2024186

Author name not available (Why is that?)

Publication date: 3 May 2021

Published in: (Search for Journal in Brave)

Abstract: One of the most striking but mysterious properties of the sinh-Gordon model (ShG) is the $bightarrow1/b$ self-duality of its $S$-matrix, of which there is no trace in its Lagrangian formulation. Here $b$ is the coupling appearing in the model's eponymous hyperbolic cosine present in its Lagrangian, $cosh(bphi)$. In this paper we develop truncated spectrum methods (TSMs) for studying the sinh-Gordon model at a finite volume as we vary the coupling constant. We obtain the expected results for $bll1$ and intermediate values of $b$, but as the self-dual point $b=1$ is approached, the basic application of the TSM to the ShG breaks down. We find that the TSM gives results with a strong cutoff $E_c$ dependence, which disappears according only to a very slow power law in $E_c$. Standard renormalization group strategies -- whether they be numerical or analytic -- also fail to improve upon matters here. We thus explore three strategies to address the basic limitations of the TSM in the vicinity of $b=1$. In the first, we focus on the small-volume spectrum. We attempt to understand how much of the physics of the ShG is encoded in the zero mode part of its Hamiltonian, in essence how `quantum mechanical' vs `quantum field theoretic' the problem is. In the second, we identify the divergencies present in perturbation theory and perform their resummation using a supra-Borel approximate. In the third approach, we use the exact form factors of the model to treat the ShG at one value of $b$ as a perturbation of a ShG at a different coupling. In the light of this work, we argue that the strong coupling phase $b>1$ of the Lagrangian formulation of model may be different from what is na"ively inferred from its $S$-matrix. In particular, we present an argument that the theory is massless for $b>1$.

Full work available at URL: https://arxiv.org/abs/2007.00154

zbMATH Keywords

No records found.

Mathematics Subject Classification ID

No records found.

This page was built for publication: Approaching the self-dual point of the sinh-Gordon model

Report a bug (only for logged in users!)Click here to report a bug for this page (MaRDI item Q2024186)