A weak approximation for the Wiener–Hopf factorization

The Wiener–Hopf factorization plays a crucial role in studying various mathematical problems. Unfortunately, in many situations, the Wiener–Hopf factorization cannot provide closed form solutions and one has to employ some approximation techniques to find its solutions. This article provides several weak, approximation for a given Wiener–Hopf factorization problem. Application of our finding in spectral factorization and Lévy processes have been given