Partial Differential Operators and Fourier Integral Operators in the Gevrey setting and applications

Abstract: We state and prove here semiclassical results about the construction of asymptotic solutions by the WKB method for pseudo-differential equations of real principal type. It is a Gevrey version; the smooth $C^\infty$ and the analytic ones may be found in H\"ormander (Hormander1985) and Sj\"ostrand (Sj\"ostrand1982). We present here three versions depending on the degree of entrance in the complex domain.