Haldane relation for interacting dimers

TL;DR

This paper proves a Haldane relation linking critical exponents and Gaussian field amplitudes in an interacting dimer model, confirming the effective field theory description and connecting to universality conjectures.

Contribution

It rigorously establishes the Haldane relation for interacting dimers, validating the Gaussian free field description and extending universality concepts to this lattice model.

Findings

Proved the identity between two-point correlation exponent and Gaussian field amplitude.

Confirmed the Gaussian field description of the interacting dimer model.

Suggested convergence of a lattice curve to SLE$_\kappa$ process.

Abstract

We consider a model of weakly interacting, close-packed, dimers on the two-dimensional square lattice. In a previous paper, we computed both the multipoint dimer correlations, which display non-trivial critical exponents, continuously varying with the interaction strength; and the height fluctuations, which, after proper coarse graining and rescaling, converge to the massless Gaussian field with a suitable interaction-dependent pre-factor (`amplitude'). In this paper, we prove the identity between the critical exponent of the two-point dimer correlation and the amplitude of this massless Gaussian field. This identity is the restatement, in the context of interacting dimers, of one of the Haldane universality relations, part of his Luttinger liquid conjecture, originally formulated in the context of one-dimensional interacting Fermi systems. Its validity is a strong confirmation of the effective massless Gaussian field description of the interacting dimer model, which was guessed on the basis of formal bosonization arguments. We also conjecture that a certain discrete curve defined at the lattice level via the Temperley bijection converges in the scaling limit to an SLE$_\kappa$ process, with $\kappa$ depending non-trivially on the interaction and related in a simple way to the amplitude of the limiting Gaussian field.