A general approach due to J. Delves [J. Inst. Math. Appl. 20, 173- 182 (1977; Zbl 0404.65062)] for solving operator equations iteratively by Galerkin methods is elaborated for Fredholm integral equations of the first kind whose kernels have a logarithmic principle part. Essentially, the method consists of splitting the matrix A resulting from the Fourier- Galerkin approach, with , computing the Cholesky decomposition , and applying Jacobi iteration preconditioned by the inverse of B.
The method is here in particular applied to G. T. Symm’s integral equation for computing the conformal mapping of a simply connected region onto the unit disk [Numer. Math. 9, 250-258 (1966; Zbl 0156.169)] and to corresponding integral equations for doubly and multiply connected regions. In the simply connected case the method generalizes one proposed by P. Henrici [SIAM Rev. 21, 481-527 (1979; Zbl 0416.65022)], where B is the diagonal matrix corresponding to the logarithmic principle part of the kernel.