Tuesday Seminar on Topology

Seminar information archive ～10/07｜Next seminar｜Future seminars 10/08～

Date, time & place Tuesday 16:00 - 17:30 056Room #056 (Graduate School of Math. Sci. Bldg.)
Organizer(s) IKE Yuichi, KONNO Hokuto, SAKASAI Takuya

Future seminars

2026/10/13

16:00-17:30   Room #hybrid/123 (Graduate School of Math. Sci. Bldg.)
Pre-registration required. See our seminar webpage.
Léo Bénard (Aix-Marseille Université)
On a Langlands duality conjecture for character varieties of 3 manifolds (ENGLISH)
[ Abstract ]
Inspired by a similar conjecture for skein modules of 3 manifolds formulated by Ben-Zvi, Gunningham, Jordan and Safronov, we conjecture that for G complex reductive group and L(G) its Langlands dual, for a 3 manifold M, if the character varieties X(M, G) and X(M, L(G)) are finite, then they have the same cardinality counted with multiplicity. We will discuss examples, non-examples, non-reduced points, and describe the cases where we can prove this statement. This is joint work with Renaud Detcherry (Dijon).
[ Reference URL ]
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html

2026/10/20

17:30-18:30   Room #hybrid/056 (Graduate School of Math. Sci. Bldg.)
Pre-registration required. See our seminar webpage.
Ken’ichi Ohshika (Gakushuin University)
Structures of unit tangent spheres of Thurston’s metric (JAPANESE)
[ Abstract ]
Thurston introduced in the 1980s a new metric on Teichmüller space using best Lipschitz maps instead of best quasi-conformal maps. Thurston’s metric is Finsler, and so we can consider the associated norm on tangent spaces of Teichmüller space. In this talk, we show how the unit sphere of this norm looks, regarded as a convex sphere. We in particular give a formula for dimensions of faces. This is a part of joint work with A. Papadopoulos.
[ Reference URL ]
https://park.itc.u-tokyo.ac.jp/MSF/topology/TuesdaySeminar/index_e.html