Classical O(n) lattice model
= Classical O(n) lattice model
{c}
{title2=$O(n)$}
The classical O(n) lattice model assigns a unit vector $\sigma_x\in S^{n-1}$ to each lattice site and gives ferromagnetic nearest-neighbour configurations weight proportional to $\exp(\beta\sum_{xy}\sigma_x\cdot\sigma_y+h\sum_x\sigma_x\cdot e)$.