Lagrangian Manifolds and the Maslov Operator

This book presents the topological and analytical foundations of the theory of Maslov's canonical operator for finding asymptotic solutions of a wide class of pseudodifferential equations. The topology and geometry of Lagrangian manifolds are studied in detail and the connections between Fourier integral operators and canonical operators established. Applications are proposed for the asymptotic solutions to the Cauchy problem and for the asymptotics of the spectra of non-self-dual operators. The authors set out to make more accessible to a wider readership - of specialists in topology, differential equations and functional analysis, including research students - the ideas of Maslov which were much more difficult and opaque in their original published form (1965). The book has been updated, as compared with the Russian edition, by numerous revisions within the text and the addition of two new chapters on more recent work.