100, rue des maths 38610 Gières / GPS : 45.193055, 5.772076 / Directeur : Louis Funar

Juan Souto

Ergodicty of the mapping class group action on a component of the character variety.
Jeudi, 23 Octobre, 2014 - 14:00
Résumé : 

Goldman proved that the variety Xg of conjugacy classes of representations of a surface group of genus g into PSL2R has 4g3
connected components Xg(22g),,Xg(2g2) indexed by the Eulernumber of the representations therein. The two extremal components Xg(22g) and
Xg(2g2) correspond to Teichmueller spaces on which the mapping class group acts discretely. On the other hand Goldman conjectured that the action on
each one ofl the other components is ergodic. I will explain why this is indeed the case the component Xg(0) consisting of representations with
Eulernumber 0 and for all g3. The basic technical result is a formula relating the euler number of a representation and the infimum of the
energies of equivariant harmonic maps where the infimum is taken over all maps and all conformal structures on the surface of genus g.

Institution de l'oratrice / orateur: 
Rennes
Thème de recherche : 
Théorie spectrale et géométrie
Salle : 
4
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