## Tuesday Seminar on Topology

Date, time & place Tuesday 17:00 - 18:30 056Room #056 (Graduate School of Math. Sci. Bldg.) KOHNO Toshitake, KAWAZUMI Nariya, KITAYAMA Takahiro, SAKASAI Takuya Tea: 16:30 - 17:00 Common Room

### 2020/07/28

17:00-18:00   Online
Pre-registration required. See our seminar webpage.
Anderson Vera (RIMS, Kyoto University)
A double filtration for the mapping class group and the Goeritz group of the sphere (ENGLISH)
[ Abstract ]
I will talk about a double-indexed filtration of the mapping class group and of the Goeritz group of the sphere, the latter is the group of isotopy classes of self-homeomorphisms of the 3-sphere which preserves the standard Heegaard splitting of $S^3$. In particular I will explain how this double filtration allows to write the Torelli group as a product of some subgroups of the mapping class group. A similar study could be done for the group of automorphisms of a free group. (work in progress with K. Habiro)
[ Reference URL ]
https://zoom.us/webinar/register/WN_oS594Z6BRyaKNCvlm3yCoQ