[Binghamton Geometry Topology Seminar] Seminar This Week

[Matthew R Haulmark]

Hi everyone,

This week our speaker is Rylee Lyman of Rutgers University. Links and
details are below.

Zoom link for the seminar, 2:50 - 3:50:
https://binghamton.zoom.us/j/94057178271

Zoom link for the coffee, 12:30 - 1:30:
https://binghamton.zoom.us/j/96674397432

*Title:  *Nielsen realization for infinite-type surfaces

*Abstract: * We learn the classification of surfaces early in our
mathematical careers: the homeomorphism type of an orientable surface
with finitely generated fundamental group is determined by genus,
punctures and boundary components. Without the finite generation
assumption, there is still a classification, due to Kerékjártó and
Richards. These surfaces are of infinite type. Associated to any
surface is its mapping class group. A famous theorem of Kerckhoff from
1983 solves the "Nielsen realization" problem posed in 1932: finite
subgroups of the mapping class group of a finite-type surface of
negative Euler characteristic are exactly the groups of isometries of
some hyperbolic metric on the surface. Recently, joint with Santana
Afton, Danny Calegari and Lvzhou Chen, I extended Kerckhoff's theorem to
orientable, infinite-type surfaces. I'd like to introduce infinite-type
surfaces and discuss the theorem and some of its consequences.


See you on Thursday!

Best,

Matt
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