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CATEGORIES:Isaac Newton Institute Seminar Series
SUMMARY:Computational Wave Propagation in the Spirit of th
e Geometrical Theory of Diffraction - Dave Hewett
(University College London)
DTSTART;TZID=Europe/London:20170303T094500
DTEND;TZID=Europe/London:20170303T100500
UID:TALK71225AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/71225
DESCRIPTION:Geometrical (ray-based) techniques for high freque
ncy wave scattering have been with us for centurie
s\, but until relatively recently were applicable
only to smooth scatterers. The Geometrical Theory
of Diffraction (GTD)\, pioneered by Joe Keller and
developed by numerous others since the 1960s\, pr
ovided a powerful new methodology for scatterers w
ith corners and sharp edges. It is a beautiful\, w
ide-ranging and highly intuitive theory\, inspired
by physics but mathematically grounded in the the
ory of matched asymptotic expansions. GTD is an as
ymptotic theory. But it has also had significant i
nfluence on the direction of research into computa
tional methods. Indeed\, the past decade has seen
exciting new developments in `hybrid numerical-asy
mptotic'\; (HNA) methods\, which use FEM or BEM
approximation spaces built from oscillatory basis
functions\, which are chosen by reference to the
GTD. (In fact\, Keller himself published a paper d
escribing such a method.) For many basic scatterin
g problems HNA methods achieve the `holy grail'
\; of providing fixed accuracy with frequency-inde
pendent computational cost. In this talk I will ou
tline the HNA approach and celebrate the ongoing r
ole that Keller'\;s GTD is playing in its devel
opment.
LOCATION:Seminar Room 1\, Newton Institute
CONTACT:INI IT
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