A bijection theorem for domino tiling with diagonal impurities

Abstract

We consider the dimer problem on a non-bipartite graph $G$, where there are two types of dimers one of which we regard impurities. Results of simulations using Markov chain seem to indicate that impurities are tend to distribute on the boundary, which we set as a conjecture. We first show that there is a bijection between the set of dimer coverings on $G$ and the set of spanning forests on two graphs which are made from $G$, with configuration of impurities satisfying a pairing condition. This bijection can be regarded as a extension of the Temperley bijection. We consider local move consisting of two operations, and by using the bijection mentioned above, we prove local move connectedness. We further obtained some bound of the number of dimer coverings and the probability finding an impurity at given edge, by extending the argument in our previous result.