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`Simple calculations of loop operators in supersymmetric gauge theories'

Abstract: I will review recent development in the calculation of Wilson 
loops in 4d gauge theories with N=4 and N=2 supersymmetry. With N=4 SUSY
the result is very simple and can be compared to classical string 
calculations. With N=2 SUSY, the calculation is given in terms of a 
2d CFT: Liouville field theory. Lastly I will explain how these results 
can be extended to calculate a very interesting non-perturbative 
observable in gauge theories: 't Hooft loops.
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