The Boundary-Layer Method in Diffraction Problems

Translator's Introduction.- 1 Introduction.- 2 The Ray Method.- 2.1 The Starting Point: Formulas for the Scalar Case.- 2.2 The Eikonal Equation; Rays; Wave Fronts.- 2.3 Ray Coordinates.- 2.4 Fundamental Recurrence Formulas.- 2.5 Reflection of a Wave Given by a Ray Expansion.- 3 The Caustic Problem.- 3.1 Ray Expansion in the Neighborhood of a Caustic.- 3.2 The Analytic Nature of the Eikonal for Incoming and Outgoing Waves Near a Caustic.- 3.3 Ray Series in (s,n) and (s,?) Coordinates.- 3.4 The Field in a Boundary Layer Surrounding the Caustic.- 3.5 Fundamental Formulas.- 4 Whispering Gallery and Creeping Waves.- 4.1 Whispering Gallery Waves.- 4.2 Whispering Gallery Quasimodes.- 4.3 Creeping Waves.- 4.4 The Friedlander-Keller Solution (Diffraction Rays).- 4.5 Matching of Creeping Waves and Diffraction Rays.- 5 Oscillations Concentrated in the Neighborhood of a Ray (Gaussian Beams).- 5.1 Rays in the First Approximation.- 5.2 Derivation of the Boundary-Layer Equation.- 5.3 Solution of the System of Recurrence Equations for Vj.- 5.4 Stability of an Extremal Diameter of a Region.- 5.5 Quasimodes of the "Bouncing-Ball" Type in the First Approximation.- 5.6 Construction of Higher Approximations.- 6 Shortwave Diffraction from a Smooth Convex Body.- 6.1 The Parabolic Equation Method.- 6.2 The Analytic Nature of the Functions $$ {{rm{bar V}}_{rm{j}}} $$ and Vj..- 6.3 The Boundary Layer in the Deep Shadow Zone.- 6.4 Continuation of the Solution from the Vicinity of the Point C into the Transition Region.- 6.5 Analytic Representation of the Incident Wave in the Neighborhood of the Limiting Ray.- 6.6 System of Recurrence Equations for the Neighborhood of the Limiting Ray.- 6.7 Extension of the Transition Region Formulas into the Neighborhood of the Limiting Ray.- 6.8 Formulas for the Field in the Shadow and in the Penumbra.- 7 The Problem of an Oscillating Point Source.- 7.1 The Ray Method for a Central Field of Rays.- 7.2 Expansion in the Transition Region.- 7.3 Expansions in the Neighborhood of the Origin.- 8 Survey of Literature.- References.