## Electronic Journal of Probability

### Height representation of XOR-Ising loops via bipartite dimers

#### Abstract

The XOR-Ising model on a graph consists of random spin configurations on vertices of the graph obtained by taking the product at each vertex of the spins of two independent Ising models. In this paper, we explicitly relate loop configurations of the XOR-Ising model and those of a dimer model living on a decorated, bipartite version of the Ising graph. This result is proved for graphs embedded in compact surfaces of genus $g$. Using this fact, we then prove that XOR-Ising loops have the same law as level lines of the height function of this bipartite dimer model. At criticality, the height function is known to converge weakly in distribution to $\frac{1}{\sqrt{\pi}}$ a Gaussian free field. As a consequence, results of this paper shed a light on the occurrence of the Gaussian free field in the XOR-Ising model. In particular, they provide a step forward in the solution of Wilson's conjecture, stating that the scaling limit of XOR-Ising loops are level lines of the Gaussian free field.

#### Article information

Source
Electron. J. Probab., Volume 19 (2014), paper no. 80, 33 pp.

Dates
Accepted: 4 September 2014
First available in Project Euclid: 4 June 2016

https://projecteuclid.org/euclid.ejp/1465065722

Digital Object Identifier
doi:10.1214/EJP.v19-2449

Mathematical Reviews number (MathSciNet)
MR3256880

Zentralblatt MATH identifier
1302.82014

Rights

#### Citation

Boutillier, Cédric; de Tilière, Béatrice. Height representation of XOR-Ising loops via bipartite dimers. Electron. J. Probab. 19 (2014), paper no. 80, 33 pp. doi:10.1214/EJP.v19-2449. https://projecteuclid.org/euclid.ejp/1465065722

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