BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Contour integral solutions of the parabolic wave equation and appl
 ications to canonical scattering problems - David Hewett (University Colle
 ge London)
DTSTART:20230207T153000Z
DTEND:20230207T161500Z
UID:TALK194767@talks.cam.ac.uk
DESCRIPTION:We present a simple\, systematic construction and analysis of 
 solutions of the two dimensional parabolic (or paraxial) wave equation tha
 t exhibit far-field localisation near certain algebraic plane curves. Our 
 solutions are complex contour integral superpositions of elementary plane 
 wave solutions with polynomial phase\, the desired localisation being asso
 ciated with the coalescence of saddle points. Our solutions provide a unif
 ied framework in which to describe some classical phenomena in two-dimensi
 onal high frequency wave propagation\, including smooth and cusped caustic
 s\, whispering gallery and creeping waves\, and tangent ray diffraction by
  a smooth boundary. We also study a subclass of solutions exhibiting local
 isation near a cubic parabola\, and discuss their possible relevance to th
 e study of the canonical inflection point problem governing the transition
  from whispering gallery waves to creeping waves.
LOCATION:Seminar Room 1\, Newton Institute
END:VEVENT
END:VCALENDAR