There is showed how to define the second analytic wave front set in order to obtain propagation properties for differentiable, Gevrey, or analytic singularities of distributions without second analytic support.
Cite this article
Patrick Esser, Second Microlocalization and Propagation Theorems for the Wave Front Sets. Z. Anal. Anwend. 6 (1987), no. 6, pp. 505–515