Exact densities of loops in O(1) dense loop model and of clusters in critical percolation on a cylinder II: rotated lattice

Abstract

This work continues the study started in \cite{Povolotsky2021}, where the exact densities of loops in the O(1) dense loop model on an infinite strip of the square lattice with periodic boundary conditions were obtained. These densities are also equal to the densities of critical percolation clusters on the forty five degree rotated square lattice rolled into a cylinder. Here, we extend those results to the square lattice with a tilt. This in particular allow us to obtain the densities of critical percolation clusters on the cylinder of the square lattice of standard orientation extensively studied before. We obtain exact densities of contractible and non-contractible loops or equivalently the densities of critical percolation clusters, which do not and do wrap around the cylinder respectively. The solution uses the mapping of O(1) dense loop model to the six-vertex model in the Razumov-Stroganov point, while the effective tilt is introduced via the the inhomogeneous transfer matrix proposed by Fujimoto. The further solution is based on the Bethe ansatz and Fridkin-Stroganov-Zagier's solution of the Baxter's T-Q equation. The results are represented in terms of the solution of two explicit systems of linear algebraic equations, which can be performed either analytically for small circumferences of the cylinder or numerically for larger ones. We present exact rational values of the densities on the cylinders of small circumferences and several lattice orientations and use the results of high precision numerical calculations to study the finite-size corrections to the densities, in particular their dependence on the tilt of the lattice.