The discrete Gaussian model is a random lattice field model imitating the Gaussian free field but restricted to taking integer values. Given a lattice, assigning an integer value to each lattice site would give a configuration, and the probability of exhibiting a certain configuration is weighted by measuring the total amount of gradients of the configuration. Because of its relation with some fundamental problems in physics, such as the Kosterlitz-Thouless phase transition in the XY model, this model had drawn the attention of a number of mathematical physicists.
Despite the growing understanding of the topic recently, studying the exact limiting behaviour of related models often turn out to be challenging. In this talk, I will describe why the scaling limit of the 2D discrete Gaussian model can be studied with great precision.