2019/08/24 by Gourab Ray, Yinon Spinka
Mathematics · Physics and Astronomy · #Bounded function #Combinatorics #Condensed matter physics #Finitary #Function (biology) #Graph #Ising model #Markov Chains and Monte Carlo Methods #Mathematical analysis #Mathematics #Physics #Potts model #Pure mathematics #Representation (politics) #Spins #Square-lattice Ising model #Statistical physics #Stochastic processes and statistical mechanics #Theoretical and Computational Physics #Vertex (graph theory) #math.PR
paper · pdf · doi:10.1002/rsa.21032
published as Random Structures and Algorithms, 2021 · 39 pages, 8 figures
openalex publication_date 2019/08/24 · openalex created_date 2021/08/02 · arxiv created 2022/01/31 · arxiv updated 2022/02/01 · openalex updated_date 2026/08/05
It is known that the Ising model on \mathbb Zd at a given temperature is a finitary factor of an i.i.d. process if and only if the temperature is at least the critical temperature. Below the critical temperature, the plus and minus states of the Ising model are distinct and differ from one another by a global flip of the spins. We show that it is only this global information which poses an obstruction for being finitary by showing that the gradient of the Ising model is a finitary factor of i.i.d. at all temperatures. As a consequence, we deduce a volume-order large deviation estimate for the energy. A similar result is shown for the Potts model. A result in the same spirit is also shown for the six-vertex model, which is itself the gradient of a height function, with parameter c \gtrapprox 6.4. We show that the gradient of the height function is not a finitary factor of an i.i.d. process, but that its "Laplacian" is. For this, we introduce a coupling between the six-vertex model with c≥ 2 and a new graphical representation of it, reminiscent of the Edwards--Sokal coupling between the Potts and random-cluster models. We believe that this graphical representation may be of independent interest and could serve as a tool in further understanding of the six-vertex model. To provide further support for the ubiquity of this type of phenomenon, we also prove an analogous result for the so-called beach model. The tools and techniques used in this paper are probabilistic in nature. The heart of the argument is to devise a suitable tree structure on the clusters of the underlying percolation process (associated to the graphical representation of the given model), which can be revealed piece-by-piece via exploration.