Current Math Seminar
Fall 2009 - Spring 2010



Organizers: Prudence Heck and Sevak Mkrtchyan
E-mail: ptheck@indiana.edu , sevak.mkrtchyan@rice.edu

Time and place: Thursdays, 2:30-3:30 pm in 227 Brown Hall

Calendar:

Fall 2009

August
27

Organizational meeting
September
3
Darren Ong
Quasiconformal Maps and Gr\"{o}tzsch's Problem
10
Dan Tanner
Introduction to Riemann Surfaces and Teichmuller Space
17
Evelyn Lamb
Harmonic Maps and Teichmüller Space
24
Renee Laverdiere
Complex Projective Structures and Schwarzian Derivatives
October
01
James Cooper, Derek Goto
An Introduction to Cellular Homology, Covering Spaces
08
Chris Davis
Title
15
Bridget Franklin
Introduction to Contact Homology
22
Andrew Elliott
Introduction to Khovanov Homology
29
Natalie Durgin, Paul Munger
Title
November
05
Ben Waters
Locating the Algebra and the Geometry in Algebraic Geometry
12
Zhiyuan Li Title
19
Janine Dahl
Title
26

Thanksgiving
December
03
Zheng Gan
Title

Spring 2010

January
14
Taylor McNeill
The h-Cobordism Theorem Part I: Handle Decompositions
21
Taylor Coon
The h-Cobordism Theorem Part II
28
Carolyn Otto
The h-Cobordism Theorem: Part III
February
4
Ryan Scott
Hausdorff measure, hausdorff dimension, and self-similar sets
11
Colin Carroll, Zhi Zhang
Title
18
Robert Vance, Aru Ray
Title
25
Jon Chaika
Uniform Distribution
March
04

Spring Break
11
Helge Kruger
Cancelled
18
Jon Fickenscher
Ergodic Decomposition of G-invariant Measures
25
Letao Zhang
Representable Functors and Yoneda Lemma
April
1

Midterm Recess
8
Shuijing Li Title
15
Fei Xu
Title
22
Thomas McGaffey
Title

September 3: Darren Ong, Quasiconformal Maps and Gr\"{o}tzsch's Problem
There is no conformal map taking a square to a non-square rectangle. H.Gr\"{o}tzsch posed a problem in the 1920s, asking for the map of this kind that is ``closest" to being conformal. This question led to the discovery of quasiconformal maps, which now play an essential role in several branches of analysis, and in Teichm\"{u}ller Theory in particular.

September 10: Dan Tanner, Introduction to Riemann Surfaces and Teichmuller Space
The fundemental objects in Teichmuller Space are closed Riemann Surfaces. I will define Reimann Surfaces and give several equivallent definitions on Teichmuller Space. With a focus on examples, we will see the Teichmuller space of genus zero and one. Time permitting I will state Teichmuller's Theorem which gives the structure of Teichmuller Space of larger genus surfaces.

September 17: Evelyn Lamb, Harmonic Maps and Teichmüller Space
We continue where last week's lecture left off with further explanation of Teichmüller's theorem. We then show the parametrization of Teichmüller space by harmonic maps due to Wolf. We define the representation space of Riemann surfaces, of which Teichmüller space is one component, and discuss a possible extension of Wolf's parametrization to other components of representation space.

September 24: Renee Laverdiere, Complex Projective Structures and Schwarzian Derivatives
A fibre of marked complex projective structures over a point in Teichmuller space has both an analytic and geometric parameterization. The former is via bounded holomorphic quadratic differentials, and the later is via grafting. An interesting question to pursue is the interplay between the two parameterizations. This last Teichmuller Theory seminar will focus on defining complex projective structures and giving the analytic parameterization, with an introduction to the geometric parameterization if time allows.

October 1: James Cooper, Derek Goto, An Introduction to Cellular Homology, Covering Spaces
James Cooper: Homology is a tool that we use to find the higher dimensional holes that the fundamental group fails to find. This provides us another topological invariant we may use to distinguish between spaces. I define a cellular complex and n-chains on that complex. With a boundary operator, we form a chain of abelian groups of these chains. We then use this sequence of groups to define homology. I will end with examples of computing homology and, time permitting, the statement of the Mayer–Vietoris sequence.
Derek Goto: The correspondence between covering spaces and deck groups is basically Galois theory in another category. I will talk about this and go over some relevant examples. If there is time, I will say a bit about Cayley complexes.

October 8: Chris Davis, Title
Abstract

October 15: Bridget Franklin, Introduction to Contact Homology
Contact Homology, one specialized version of Floer Homology, is currently a very active area of research in Topology. In this talk, I will be following notes of a talk given by John Etnyre at the 2009 GITC as well as discussing some of what I learned at the MSRI Workshop in Symplectic and Contact Geometry and Topology. I will give a general discussion Contact Homology which studies the properties of M, a compact, oriented, 2n-1 dimensional manifold endowed with a contact structure. I will specialize this to the discussion of Legendrian Contact Homology which gives an invariant of Legendrian submanifolds of M, which is useful in the study of the isotopy classes of Legendrian knots in R^3 given the standard contact structure. If time permits, we will look at relationships between Contact Homology and other Floer Homology Theories.

October 22: Andrew Elliot, Introduction to Khovanov Homology
Khovanov homology is a categorification of the Jones polynomial, a polynomial knot invariant discovered in the mid 80s. I will discuss what this statement means, in the context of constructing the Khovanov chain complex. I will also talk about how we measure the amount of new information Khovanov homology can bring to the table, and how similar features show up in other categorifications of knot polynomials.

October 29: Natalie Durgin, Paul Munger, Title
Abstract

November 5: Ben Waters, Locating the Algebra and the Geometry in Algebraic Geometry
The main purpose of my talk will be to develop some of the elementary theory around sheaves and varieties in Algebraic Geometry. I will conclude my talk with a demonstration of how to view projective space as a variety.

November 12: Zhiyuan Li, Title
Abstract

November 19: Janine Dahl, Title
Abstract

December 3: Zheng Gan, Title
Abstract

January 14: Taylor McNeill, The h-Cobordism Theorem Part I: Handle Decompositions
I will give an introduction to handles, including handle decompositions, handle cancellation, and obtaining homology from handles. This will be useful in proving the h-cobordism theorem later in the series.

January 21: Taylor Coon, The h-Cobordism Theorem Part II
I will give some background needed to state and understand the h-Cobordism theorem and outline its proof.

January 28: Carolyn Otto, The h-Cobordism Theorem: Part III
I will discuss the more technical details of the proof of the h-cobordism theorem, specifically the "Whitney Trick". The Whitney trick will demonstrate why this theorem does not work for dimension n=4. I will also give a similar theorem for when our manifolds are not simply connected.

February 5: Ryan Scott, Hausdorff measure, hausdorff dimension, and self-similar sets
Abstract

February 12: Colin Carroll, Zhi Zhang, Title
Abstract

February 19: Robert Vance, Aru Ray, Title
Abstract

February 26: Jon Chaika, Uniform Distribution
This talk will introduce the notion of uniform distribution. Weyl's criterion and Van der Corput's difference theorem will be stated. Examples and non-examples will be presented. If time permits variants of uniform distribution will be discussed.

March 11: Helge Kruger, Cancelled
Cancelled

March 18: Jon Fickenscher, Ergodic Decomposition of G-invariant Measures
Abstract

March 25: Letao Zhang, Representable Functors and Yoneda Lemma
Abstract

April 8: Shuijing Li, Title
Abstract

April 15: Fei Xu, Title
Abstract

April 22: Thomas McGaffey, Title
Abstract