## Seminars and Colloquia by Series

### The Arc Complex and Open Book Decompositions

Series
Geometry Topology Student Seminar
Time
Wednesday, January 30, 2013 - 13:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Meredith CaseyGeorgia Tech
This is an expository talk on the arc complex and translation distance of open book decompositions. We will discuss curve complexes, arc complex, open books, and finally the application to contact manifolds.

### Knots and Dynamics II

Series
Geometry Topology Student Seminar
Time
Wednesday, January 23, 2013 - 13:05 for 1 hour (actually 50 minutes)
Location
Skiles 006.
Speaker
Amey KalotiGeorgia Tech
This is continuation of talk from last week. Periodic orbits of flows on $3$ manifolds show very rich structure. In this talk we will try to prove a theorem of Ghrist, which states that, there exists vector fields on $S^3$ whose set of periodic orbits contains every possible knot and link in $S^3$. The proof relies on template theory.

### Knots and Dynamics

Series
Geometry Topology Student Seminar
Time
Wednesday, January 16, 2013 - 13:00 for 1 hour (actually 50 minutes)
Location
Skiles 006.
Speaker
Amey KalotiGeorgia Tech

### Braid Groups and Hodge Theory

Series
Geometry Topology Student Seminar
Time
Wednesday, November 14, 2012 - 14:05 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Becca WinarskiGeorgia Tech
We look at a paper of McMullen "Braid Groups and Hodge Theory" exploring representations of braid groups and their connections to arithemetic lattices.

### Stein fillings of planar open books.

Series
Geometry Topology Student Seminar
Time
Wednesday, October 31, 2012 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 006.
Speaker
Amey KalotiGeorgia Tech
The goal of this talk is to study geography and classification problem for Stein fillings of contact structures supported by planar open books. In the first part we will prove that for contact structures supported by planar open books Stein fillings have a finite geography. In the second part we will outline an approach to classify Stein fillings of manifolds supported by planar open books.

### Talk in Geometry-Topology Research Seminar Today

Series
Geometry Topology Student Seminar
Time
Wednesday, October 24, 2012 - 14:00 for 1 hour (actually 50 minutes)
Location
none
Speaker
nonenone

### Toric Manifolds - Four Dimensions from Two

Series
Geometry Topology Student Seminar
Time
Wednesday, September 12, 2012 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Jamie ConwayGeorgia Tech
We will investigate a method of "seeing" properties of four dimensional symplectic spaces by looking at two dimensional pictures. We will see how to calculate the Euler characteristic, identify embedded surfaces, see intersection numbers, and how to see induced contact structures on the boundary of these manifolds.

### Topological entropy of automorphisms of free groups

Series
Geometry Topology Student Seminar
Time
Wednesday, September 5, 2012 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Hyunshik ShinSchool of Mathematics
The main goal is to characterize the dilatation of an outer automorphisms of free groups. It is known that for any automorphism, its dilatation is a weak Perron number. The converse was recently shown by Thurston; for every weak Perron number, there is an automorphism represented by a train track map. We will discuss Thurston's theorem and its proof.

### Train track and automorphisms of free groups

Series
Geometry Topology Student Seminar
Time
Wednesday, August 29, 2012 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Hyunshik ShinSchool of Mathematics, Georgia Tech
We will discuss the basics of automorphisms of free groups and train track structure. We will define the growth rate which is a topological entropy of the train track map.

### Gel'fand Duality

Series
Geometry Topology Student Seminar
Time
Wednesday, February 8, 2012 - 14:05 for 1 hour (actually 50 minutes)
Location
Skiles 169
Speaker
Jonathan PaprockiGeorgia Tech
We will prove a duality between locally compact Hausdorff spaces and the C*-algebra of continuous complex-valued functions on that space. Formally, this is the equivalence of the opposite category of commutative C*-algebras and the category of locally compact Hausdorff spaces.