__________________________________________________________________________
_______________ Uniqueness in Inverse Obstacle Scattering.
_____________________ Rainer Kress  (University of Goettingen, Germany)
_______________________________________________________________ Wednesday, 16h00: November 3, 2004
_______________________________________________________________________________Sala 3.10
___________________Abstract: 
___________________ The inverse problem we consider in this survey is to determine the shape of an obstacle from 
___________________ the knowledge of the far field pattern for the scattering of time-harmonic waves. We will 
___________________ concentrate on uniqueness issues, i.e., we will investigate under what conditions an obstacle 
___________________ and its boundary condition can be identified from a knowledge of its far field patterns for incident 
___________________ plane waves. We will review some classical and some recent results and draw attention to 
___________________ open problems.
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Previous seminars:
__________________________________________________________________________
_______________ Helmholtz Problems in a Halfspace with an Impedance Condition.
_____________________ Jean Claude Nédélec  (Ecole Polytechnique, France)
______________________________________________________________________ Friday, 16h30: July 23, 2004
_______________________________________________________________________________Sala P4.35
___________________Abstract: 
___________________ We will discuss the radiation condition to impose in this kind of problems.
___________________
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__________________________________________________________________________
_______________ The essence of TQFT
_____________________ Roger Picken  (CEMAT- IST)
__________________________________________________________________ Wednesday, 16h00: June 30, 2004
_______________________________________________________________________________Anfiteatro PA.1
___________________Abstract: 
___________________TQFT, the acronym for Topological Quantum Field Theory, is a 
___________________construction which arose in physics, but has found applications in
___________________several areas of mathematics, in particular the theory of knots, braids 
___________________and similar objects. The purpose of this talk is to explain some of the 
___________________underlying notions, in such a way as to be accessible to people with a 
___________________wide range of mathematical backgrounds.
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