Journal of Statistical Physics, Vol. 52, Nos. 3/4, 1988, p. 795-813.
The dispersion expansion for the spin correlation function in the two-dimen-
sional Ising model with linear defects below 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.