Journal of Statistical Physics, Vol. 52, Nos. 3/4, 1988. p. 815-827.
The dispersion expansion for the spin correlation function in the two-dimensional Ising model with linear defects above Tc is derived. The asymptotic behavior is computed by a steepest descent analysis. The lattice is divided into four domains with different asymptotic behaviors. In particular, the correlation length inside certain domains is a function of the defect.