Current contact: Thomas Ng and Zachary Cline.

The seminar takes place on Fridays (from 1:00-2:00pm) in Room 617 on the sixth floor of Wachman Hall. Pizza and refreshments are available beforehand in the lounge next door.

• Friday February 3, 2017 at 13:00, Wachman 617
Introduction to Deformation Theory

Elif Altinay-Ozaslan, Temple University

• Friday February 10, 2017 at 13:00, Wachman 617
Studying fundamental groups through representation theory

Timothy Morris, Temple University

• Friday February 17, 2017 at 13:00, Wachman 617
Growth of groups: an introduction to geometric group theory

Thomas Ng, Temple University

• Friday March 10, 2017 at 13:00, Wachman 617
What are Hopf algebras and why should you care?

Zachary Cline, Temple University

• Friday March 24, 2017 at 13:00, Wachman 617
TBA

• Friday April 21, 2017 at 13:00, Wachman 617
TBA

Kathryn Lund, Temple University

• Friday September 15, 2017 at 13:00, Wachman 617
The complex of curves of a surface

Thomas Ng, Temple University

We will explore the definition and properties of this object and its role in studying 2 and 3 dimensional topology. With some luck we will see the definition of a simplicial complex, hear a little about the mapping class group (the group of homeomorphisms of a surface... sorta), or stumble across a unicorn or two (provided we are punctured).

• Friday September 29, 2017 at 13:00, Wachman 617
Representations from roots of the Alexander polynomial

Timothy Morris, Temple University

• Friday October 13, 2017 at 13:00, Wachman 617
Partitions of equiangular tight frames

Presentation on a new efficient algorithm to construct partitions of a special class of equiangular tight frames (ETFs) that satisfy the operator norm bound established by a theorem of Marcus, Spielman, and Srivastava (MSS), which they proved as a corollary yields a positive solution to the Kadison–Singer problem.

• Friday October 20, 2017 at 13:00, Wachman 617

Operads are, loosely speaking, gadgets that encode various flavors of algebras: associative, commutative, Lie, A-infinity, etc., and they have a wide range of applications: deformation theory, algebraic topology, and mathematical physics, to name a few. While the formal definition of an operad may look daunting, we’ll see that it is really quite intuitive. To begin, we’ll have a brief discussion of symmetric monodical categories (which are needed to define operads) and then proceed to define and look at examples of operads.

• Friday October 27, 2017 at 13:00, Wachman 617
2 is an algebra!: a bit of abstract nonsense

Zachary Cline, Temple University

• Friday November 10, 2017 at 13:00, Rm 617
Construction of solutions of a functional system of ODEs with applications to bichromatic lens design

In this talk we will consider the following system of ODE $$Z'(t) = H(t; Z(t), Z(z_1(t)), Z'(t), Z'(z_1(t))), \qquad Z(0) = 0$$ with $Z=(z_1, \dots, z_n) \in \mathbb{R}^n$ and $H(\mathbb{R}^{4n+1} \to \mathbb{R}^n)$ a given Lipschitz continuous function. We show using a fixed point argument that under some conditions on $H$ the system has a unique local solution. We use this result to construct lenses that refract bichromatic rays (2 colors) emitted from a point source into a parallel beam.