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SUMMARY:Gunther Uhlmann (University of Washington\, USA)
DTSTART:20201013T123000Z
DTEND:20201013T133000Z
DTSTAMP:20260423T022726Z
UID:WOPARA/7
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/WOPARA/7/">S
 eeing Through Space Time</a>\nby Gunther Uhlmann (University of Washington
 \, USA) as part of Webinar on PDE and related areas\n\n\nAbstract\ne consi
 der inverse problems for the Einstein equation with a time-depending metri
 c on a 4-dimensional globally hyperbolic Lorentzian manifold.We formulate 
 the concept of active measurements for relativistic models.  Wedo this by 
 coupling Einstein equations with equations for scalar fields.The inverse p
 roblem we study is the question of whether the observationsof the solution
 s of the coupled system in an open subset of the space-time withthe source
 s supported in this set determines the metric in a larger domain.  Tostudy
   this  problem  we  define  the  concept  of  light  observation  sets  a
 nd  showthat knowledge of these sets determine the conformal class of the 
 metric.  Thiscorresponds to passive observations from a distant area of sp
 ace which is filledby light sources.We will start by considering inverse p
 roblems for scalar non-linear hyperbolicequations to explain our method. N
 o previous knowledge of Lorentzian geometryor general relativity will be a
 ssumed.This is based on joint work with P. Hinz\, Y. Kurylev\, M. Lassas\,
  Y. Wangand J. Zhai\n
LOCATION:https://researchseminars.org/talk/WOPARA/7/
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