Gradient Gibbs measures with non-convex potentials and the universality class of the Gaussian Free Field

Simon Buchholz, Codina Cotar, Florian Schweiger

We study a general class of gradient interface models with Hamiltonian $H=\beta \sum V(\nabla \varphi )$, $\beta >0$, assuming essentially that the potential $V$ is even, $V^{\prime }(s)\ge \alpha s$ on $[0,\infty…