High Accuracy Method for Integral Equations with Discontinuous Kernels

A new highly accurate numerical approximation scheme based on a Gauss type Clenshaw-Curtis Quadrature for Fredholm integral equations of the second kind, whose kernel is either discontinuous or not smooth along the main diagonal, is presented. This scheme is of spectral accuracy when the kernel is infinitely differentiable away from the main diagonal, and is also applicable when the kernel is singular along the boundary, and at isolated points on the main diagonal. The corresponding composite rule is described. Application to integro-differential Schroedinger equations with non-local potentials is given.