  We consider Gibbs distributions on permutations of a locally finite infinite
set $X\subset\mathbb{R}$, where a permutation $\sigma$ of $X$ is assigned
(formal) energy $\sum_{x\in X}V(\sigma(x)-x)$. This is motivated by Feynman's
path representation of the quantum Bose gas; the choice $X:=\mathbb{Z}$ and
$V(x):=\alpha x^2$ is of principal interest. Under suitable regularity
conditions on the set $X$ and the potential $V$, we establish existence and a
full classification of the infinite-volume Gibbs measures for this problem,
including a result on the number of infinite cycles of typical permutations.
Unlike earlier results, our conclusions are not limited to small densities
and/or high temperatures.
