The GT seminar meets on Fridays
in Math
520, at 2 PM (overflow seminars Thursday 2:40pm Room 507).

Organizer:
Walter Neumann.

Other
area seminars. Our e-mail
list. Archive of previous semesters

Date | Speaker | Title |
---|---|---|

January 20 | Organizational Meeting | Room 520, 2pm |

February 3 | Victoria Akin, Chicago | Point-pushing in the mapping class group |

February 10 | Jonah Gaster, Boston College | TBA |

February 17 | Sarah Mousley, U. Illinois | TBA |

February 24 | Carolyn Abbott, CUNY and Wisconsin | Universal acylindrical actions |

March 3 | Feng Luo, Rutgers | TBA |

March 10 | Anh Tran, UT Dallas | TBA |

March 17 | No seminar | Spring break |

March 24 | Xinghua Gao, Illinois | TBA |

March 31 | Ilya Kofman, CUNY | TBA |

April 7 | Matthew Stover | TBA |

April 14 | TBA | TBA |

April 21 | Kevin Kordek, TAMU | TBA |

April 28 | TBA | TBA |

## Abstracts

**Victoria Akin**, Chicago

February 3

**Title**: Point-pushing in the mapping class group

The point-pushing subgroup of the mapping class group of a surface
with a marked point can be considered topologically as the subgroup
that pushes the marked point about loops in the surface. Birman, who
discovered the point-pushing map, showed that this subgroup is
abstractly isomorphic to the fundamental group of the surface,
\pi_1(S). We can characterize this point-pushing subgroup
algebraically as the only normal subgroup inside of the mapping class
group isomorphic to \pi_1(S). This uniqueness allows us to recover a
description of the outer automorphism group of the mapping class
group.

**Jonah Gaster**, Boston College

February 10

**Title**:

**Sarah Mousley**, U. Illinois

February 17

**Title**:

**Carolyn Abbott**, CUNY and Wisconsin

February 24

**Title**:Universal acylindrical actions

The class of acylindrically hyperbolic groups, which are groups
that admit a certain type of non-elementary action on a hyperbolic
space, contains many interesting groups such as non-exceptional
mapping class groups and Out(F_n) for n>1. In such a group, a
generalized loxodromic element is one that is loxodromic for some
acylindrical action of the group on a hyperbolic space. Given a
finitely generated group, one can look for an acylindrical action on a
hyperbolic space in which all generalized loxodromic elements act
loxodromically; such an action is called a universal acylindrical
action. I will discuss recent results in the search for universal
acylindrical actions, describing a class of groups for which it is
always possible to construct such an action as well as an example of a
group for which no such action exists.

**Feng Luo**, Rutgers

March 3

**Title**:

**Ahn Tran**, UT Dallas

March 10

**Title**:

**Xinghua Gao**, Illinois

March 24

**Title**:

**Ilya Kofman**, CUNY

March 31

**Title**:

**Matthew Stover**, Temple

April 7

**Title**:

**Kevin Kordek**, TAMU

April 21

**Title**:

# Other relevant information.

## Previous semesters:

Fall 2016, Spring 2016, Fall 2015, Spring 2015, Fall 2014, Spring 2014, Fall 2013, Spring 2013, Fall 2012, Spring 2012, Fall 2011, 2010/11, Spring 2010, Fall 2009, Spring 2009, Fall 2008, Spring 2008, Fall 2007, Spring 2007, Fall 2006.## Other area seminars.

- Columbia Symplectic Geometry/Gauge Theory Seminar
- All Columbia Math Dept Seminars
- CUNY Geometry and Topology Seminar
- CUNY Complex Analysis & Dynamics Seminar
- CUNY Magnus Seminar
- Princeton Topology Seminar.