Description
Book SynopsisThis book presents Maslov's canonical operator method for finding asymptotic solutions of pseudo differential equations. The classical WKB method, so named in honor of its authors: Wentzel, Kramers and Brillouin, was created for finding quasi classical approximations in quantum mechanics. The simplicity, obviousness and "physicalness" of this method quickly made it popular: specialists in mathematical physics accepted it unequivocally as one of the weapons in their arsenal. The number of publications which are connected with the WKB method in one way or another can probably no longer be counted. The alternative name of the WKB method in diffraction problem- the ray method or the method of geometric optics - indicates that the approximations in the WKB method are constructed by means of rays. More precisely, the first approximation of the WKB method is constructed by means of rays (isolating the singular part), after which the usual methods of the (regular) theory of perturbations are applied. However, the ray method is not applicable at the points of space where the rays focus or form a caustic. Mathematically this fact expresses itself in the fact that the amplitude of the waves at such points become infinite.
Table of ContentsI. The Topology of Lagrangian Manifolds.- 1. Some Topological Considerations.- 1.1 Manifolds and Bundles.- 1.2 Theorems on Transversal Regularity.- 1.3 The Index of Intersection of Submanifolds.- 1.4 Homotopy Groups.- 2. The Geometry of Real Lagrangian Manifolds.- 2.1 Lagrangian Manifolds in Hamiltonian Space.- 2.2 The Cohomology of the Lagrangian Grassmannian.- 2.3 Characteristic Classes of Lagrangian Manifolds.- 2.4 Lagrangian Manifolds in General Position.- 3. Complex Lagrangian Manifolds.- 3.1 The Grassmannian of Positive Lagrangian Planes.- 3.2 The Maslov Index of Complex Lagrangian Manifolds.- 3.3 Analysis on s-Analytic Manifolds.- 3.4 Positive Lagrangian s-Analytic Manifolds.- II. Maslov’s Canonical Operator on a Real Lagrangian Manifold.- 4. Maslov’s Canonical Operator (Real Case).- 4.1 The Construction of Maslov’s Elementary Canonical Operator.- 4.2 Commutation of Maslov’s Canonical Operator and the Hamiltonian Operator.- 5. The Asymptotics of Integrals of Rapidly Oscillating Functions with a Complex Phase.- 5.1 The Formula for Asymptotic Expansion of the Integral of a Rapidly-Oscillating Function.- 5.2 Proof of Proposition 1.2.- 6. Maslov’s Canonical Operator (Complex Case).- 6.1 Maslov’s Elementary Operator on a Complex Lagrangian Manifold.- 6.2 Commutation of the Canonical Operator and the Hamiltonian (Elementary Theory).- 6.3 Commutation of Maslov’s Canonical Operator and the Hamiltonian (General Theory).- 6.4 Other Approaches.- 6.5 Appendix. The 1/h-Fourier Transform.- 7. Some Applications.- 7.1 Asymptotic Solutions of the Cauchy Problem.- 7.2 Asymptotics of the Spectrum of 1/h-Pseudodifferential Operators.- 7.3 Systems of Equations.- Appendix. Fourier-Maslov Integral Operators (The Smooth Theory of Maslov’s Canonical Operator).- Notation Index.
