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SUMMARY:Gaussian beams on Lorentzian manifolds - Jan Sbierski (Cambridge)
DTSTART:20140512T140000Z
DTEND:20140512T150000Z
UID:TALK52276@talks.cam.ac.uk
CONTACT:Prof. Neshan Wickramasekera
DESCRIPTION:In this talk we first briefly review how one can use the Gauss
 ian beam approximation for constructing solutions to the wave equation on 
 general globally hyperbolic Lorentzian manifolds whose energy is localised
  along a given null geodesic for a finite\, but arbitrarily long time. In 
 the very special case that the Lorentzian manifold admits a timelike Killi
 ng vector field\, one can easily show that the energy of waves is a conser
 ved quantity. For general Lorentzian manifolds however\, the energy of wav
 es varies in time. \nIn this talk we present a geometric characterisation 
 of the temporal behaviour of the energy of the above mentioned Gaussian be
 ams. We conclude the talk with applications to the study of the wave equat
 ion on black hole spacetimes which arise in general relativity.\n
LOCATION:CMS\, MR13
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