2d Sinh-Gordon model on the infinite cylinder
Colin Guillarmou, Trishen S. Gunaratnam, Vincent Vargas
TL;DR
The paper provides a rigorous probabilistic construction of the massless Sinh-Gordon model on the infinite cylinder by marrying Gaussian Free Field dynamics with Gaussian multiplicative chaos. It defines a self-adjoint Sinh-Gordon Hamiltonian ${\\bf H}$ with discrete spectrum and a positive ground state, and reduces general $R$-dependent constructions to the $R=1$ case via scaling. The main results include a rigorous path integral measure on $C(\mathbb{R}, H^{-s}(\mathbb{T}_R))$, the existence and scaling of vertex correlations, and exponential decay of two-point vertex functions governed by the mass gap $(\\lambda_1-\\lambda_0)/R$. The work advances constructive QFT in 2d by providing explicit PMC-driven potentials and spectral data, with detailed open problems about the full spectrum and the $R\to\infty$ limit, and links to known CFT/Lukyanov–Zamolodchikov results in the massless regime.
Abstract
For $R>0$, we give a rigorous probabilistic construction on the cylinder $\mathbb{R} \times (\mathbb{R}/(2πR\mathbb{Z}))$ of the (massless) Sinh-Gordon model. In particular we define the $n$-point correlation functions of the model and show that these exhibit a scaling relation with respect to $R$. The construction, which relies on the massless Gaussian Free Field, is based on the spectral analysis of a quantum operator associated to the model. Using the theory of Gaussian multiplicative chaos, we prove that this operator has discrete spectrum and a strictly positive ground state.
