Abstract
The objective of this work is to study some evolution problems involving the Riesz fractional derivative with singular initial data which can be distributions. It is a question of proving the existence and uniqueness of the solutions of these problems in the extended Colombeau algebra GeR . It is established that the existence and uniqueness generalized solutions hold for both evolution problems associated to the Schr¨odinger equation and the heat equation involving the corresponding Riesz fractiononal operators derivatives.