A note on the 3D Ising model as a string theory

Abstract

It has long been argued that the continuum limit of the 3D Ising model is equivalent to a string theory. Unfortunately, in the usual starting point for this equivalence -- a certain lattice theory of surfaces -- it is not at all obvious how to take the continuum limit. In this note, I reformulate the lattice theory of surfaces in a fashion such that the continuum limit is straightforward. I go on to discuss how this new formulation may overcome some fundamental objections to the notion that the Ising model is equivalent to a string theory. In an appendix, I also discuss some aspects of fermion doubling, and the lattice fermion formulation of the 2D Ising model.