20 février 2020


Radhika Gupta (University of Bristol)
Non-uniquely ergodic arational trees in the boundary of Outer space

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Lieu : IMO, salle 2L8

Résumé : The mapping class group of a surface is associated to its Teichmüller space. In turn, its boundary consists of projective measured laminations. Similarly, the group of outer automorphisms of a free group is associated to its Outer space. Now the boundary contains equivalence classes of arational trees as a subset. There exist distinct projective measured laminations that have the same underlying geodesic lamination, which is also minimal and filling. Such geodesic laminations are called `non-uniquely ergodic’. I will talk briefly about laminations on surfaces and then present a construction of non-uniquely ergodic phenomenon for arational trees. This is joint work with Mladen Bestvina and Jing Tao.

Notes de dernières minutes : L’exposé sera précédé d’un café culturel assuré à 13h par Camille Horbez.

Non-uniquely ergodic arational trees in the boundary of Outer space  Version PDF