Lagrangian intersections and glancing points: typical transitions of phase in semiclassical approximations

Abstract

Given a semiclassical distribution $f_h$ microlocalized on a Lagrangian manifold $\Lambda_0$, $H\in C^\infty( T^\ast {\bf R}^n)$, and $H=E$ a regular energy surface, we find asymptotic solutions of the PDE $(H(x,\widehat{p})-E) \, u_h (x,E)=f_h(x)$ in terms of the Maslov canonical operator, when the Hamilton vector field $v_H$ fails to be transverse to $\Lambda_0$ at some points.