Statistical mechanics of lattice tubes

Abstract
A system of lattice tubes which provides a simplified model for the pair correlation of a uniaxial ferromagnet and the loop-loop correlation of a lattice gauge theory is introduced and studied. The system is shown to exhibit a melting transition. Two distinct tube-roughening transitions are proposed. Ornstein-Zernike scaling of the pair correlation is established outside the critical regime. This scaling is used to determine the asymptotic behavior of the number of lattice tubes.