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Friday, October 7, 2016 - 14:00 ,
Location: Skiles 006 ,
Jennifer Hom ,
Georgia Tech ,
Organizer: Jennifer Hom

The knot concordance group consists of knots in the three-sphere modulo the equivalence relation of smooth concordance. We will discuss varies ways to weaken the equivalence relation (e.g., considering locally flat concordances or concordances in more general four-manifolds) and what is known and unknown about the differences between the resulting groups.

Wednesday, October 5, 2016 - 10:05 ,
Location: Skiles 005 ,
Shane Scott ,
Georgia Tech ,
Organizer: Justin Lanier

In this lecture series, held jointly (via video conference) with the
University of Buffalo and the University of Arkansas, we aim to
understand the lecture notes by Vincent Guirardel on geometric small
cancellation. The lecture notes can be found here: https://perso.univ-rennes1.fr/vincent.guirardel/papiers/lecture_notes_pcmi.pdf This week we will begin Lecture 4.

Monday, September 26, 2016 - 10:05 ,
Location: Skiles 005 ,
Justin Lanier ,
Georgia Tech ,
Organizer: Justin Lanier

In this lecture series, held jointly (via video conference) with the University of Buffalo and the University of Arkansas, we aim to understand the lecture notes by Vincent Guirardel on geometric small cancellation. The lecture notes can be found here: https://perso.univ-rennes1.fr/vincent.guirardel/papiers/lecture_notes_pcmi.pdf

Friday, September 23, 2016 - 14:00 ,
Location: Skiles 006 ,
John Etnyre ,
Georgia Tech ,
Organizer: John Etnyre

I will discuss a process called a cork twist for relating homeomorphic but not diffeomorphic smooth 4-manifolds. This involves finding a contractible submanifold of a given 4-manifold, removing it, and re-gluing by a diffeomorphism of the boundary. This is a surprisingly simple way of relating non-diffeomorphic manifold that was discovered in the 1990s but has recently been getting a lot of attention.

Wednesday, September 21, 2016 - 10:05 ,
Location: Skiles 005 ,
Justin Lanier ,
Georgia Tech ,
Organizer: Justin Lanier

In this lecture series, held jointly (via video conference) with the
University of Buffalo and the University of Arkansas, we aim to
understand the lecture notes by Vincent Guirardel on geometric small
cancellation. The lecture notes can be found here: https://perso.univ-rennes1.fr/vincent.guirardel/papiers/lecture_notes_pcmi.pdf This week we will compete the first of two steps in proving the small cancellation theorem (Lecture 3).

Monday, September 12, 2016 - 10:05 ,
Location: Skiles 005 ,
Justin Lanier ,
Georgia Tech ,
Organizer: Justin Lanier

In this lecture series, held jointly (via video conference) with the
University of Buffalo and the University of Arkansas, we aim to
understand the lecture notes by Vincent Guirardel on geometric small
cancellation. The lecture notes can be found here: https://perso.univ-rennes1.fr/vincent.guirardel/papiers/lecture_notes_pcmi.pdf This week we will finish the section on rotating families (Lecture 3).

Friday, September 9, 2016 - 14:05 ,
Location: Skiles 006 ,
Dan Margalit ,
Georgia Institute of Technology ,
Organizer: Dan Margalit

A celebrated theorem of Nikolai Ivanov states that the automorphism group of the mapping class group is again the mapping class group. The key ingredient is his theorem that the automorphism group of the complex of curves is the mapping class group. After many similar results were proved, Ivanov made a metaconjecture that any “sufficiently rich object” associated to a surface should have automorphism group the mapping class group. In joint work with Tara Brendle, we show that the typical normal subgroup of the mapping class group (with commuting elements) has automorphism group the mapping class group. To do this, we show that a very large family of complexes associated to a surface has automorphism group the mapping class group.

Tuesday, September 6, 2016 - 11:05 ,
Location: Skiles 005 ,
Justin Lanier ,
Georgia Tech ,
Organizer: Justin Lanier
In this lecture series, held jointly (via video conference) with the University of Buffalo and the University of Arkansas, we aim to understand the lecture notes by Vincent Guirardel on geometric small cancellation. The lecture notes can be found here: https://perso.univ-rennes1.fr/vincent.guirardel/papiers/lecture_notes_pcmi.pdf

Friday, September 2, 2016 - 14:05 ,
Location: Skiles 256 ,
Dan Margalit ,
Georgia Institute of Technology ,
Organizer: Dan Margalit
A celebrated theorem of Nikolai Ivanov states that the automorphism group of the mapping class group is again the mapping class group. The key ingredient is his theorem that the automorphism group of the complex of curves is the mapping class group. After many similar results were proved, Ivanov made a metaconjecture that any “sufficiently rich object” associated to a surface should have automorphism group the mapping class group. In joint work with Tara Brendle, we show that the typical normal subgroup of the mapping class group (with commuting elements) has automorphism group the mapping class group. To do this, we show that a very large family of complexes associated to a surface has automorphism group the mapping class group.