
In this talk I will present the construction of enveloping Lie algebras via constructible fonctions on a stack of representation of a quiver (by Lusztig), as well as the geometric construction of the crystal (by Kashiwara-Saito).
I will then present how this techniques can be translated in the framework of Higgs bundles on a curve, in order to obtain loop Lie algebras.
Links:
[1] http://www.mpim-bonn.mpg.de/taxonomy/term/39
[2] http://www.mpim-bonn.mpg.de/node/3444
[3] http://www.mpim-bonn.mpg.de/node/158