# Graduate Student Advisory Committee (GSAC) Colloquium

**(**

Tuesdays, 4:35–5:35 PM, JWB 335

Math 6960–001

## Graduate Colloquium

Spring 2019Tuesdays, 4:35–5:35 PM, JWB 335

Math 6960–001

*credit hours available!*)

GSAC Home | Past Graduate Colloquia

## Quivers, representations, stability, and moduli spaces

Marin PetkovicNote the special date. Classification problem is one of the biggest open problems in
algebraic geometry. In some cases, this problem is equivalent to
classifying quiver representations. In this talk I will give a brief
introduction to quivers, their representations, and a notion of
stability. If time permits, I will illustrate the connection to
geometry with some examples.

## Poetry That Computes

China MauckNote the special date. Poetry and mathematics share many elements. Both require a
certain amount of elegance, are sometimes formulaic, and are often
riddled with hidden meanings. Some would argue that poets and
mathematicians even share an overarching goal. We will consider the
history of this interweaving of two seemingly opposing subjects and
their surprising common ground.

## Graduate student forum on teaching

Kelly MacArthurThis event is an open dialogue with Kelly MacArthur for
feedback, questions, and concerns about the teaching requirement for
PhD students. The goal of this dialogue is to discuss things that are
or are not working, and how the department might improve things going
forward. This is also an opportunity to ask why the department does
things in a certain way (for example, ""Why are the classes so tightly
supervised/coordinated?"), assuming that Kelly knows the answer. If
you're nervous to voice a particular opinion or you have a question
that you don't feel comfortable asking in front of everyone, please
write your comment or question on a sheet of paper and put it in
Kelly's box anonymously.

## Periodic Trajectories in Polygonal Billiards

Matt SmithA billiard is a classical system consisting of a point
particle confined to a region with no external forces. When the region
is a polygon, surprisingly little is known about the possible
behaviors. In fact, whether every polygon has a periodic billiard
trajectory has been open for over 200 years! Our goal is to give an
elementary introduction to this problem and the methods that have been
used to attack it in the past few decades.

## The topology of impossible shapes

Christian KlevdalAn impossible is two dimensional shape that is interpreted as
the projection of a three dimensional object that cannot exist. A key
example is the Penrose triangle, and other examples feature prominently
in the art of MC Escher. In this talk, we will discuss what makes an
impossible shape impossible, and how to precisely quantify the
impossibility of a shape through a cohomology class.

## Let There Be Light!

George DomatNote the different date: Thursday, February 14th. Imagine a room with mirrored walls and a single lamp. Will
the entire room be illuminated by this single lamp? This question was
first posed in the 1950s and has generated lots of research in dynamics
and the geometry of surfaces. We will explore the history of the
problem throughout the years. Along the way we will see how to rephrase
the question in terms of surfaces and how the work of Maryam Mirzakhani
was recently used to explore this question in rational polygons.

## AWM Lecture series

Adriana SalernoUtah's student chapter of the Association for Women in
Mathematics is pleased to announce the Spring 2019 lecture of our
speaker series. This series brings prominent female mathematicians
from across the country to Utah to share their career experiences.
This special talk will consist of an open discussion of career issues
in mathematics. All are welcome to attend. Come with questions!

## How Do Bacteria Talk? Understanding Bacterial Quorum Sensing by Mathematical Modeling

Bridget FanBacterial quorum sensing (QS) is a form of
intercellular communication that relies on the production and detection
of diffusive signaling molecules called auotinducers (AIs). Such a
mechanism allows the bacteria to track their cell density in order to
regulate group behavior, such as biolm formation and bioluminescence.
In a number of bacterial QS systems, including V. harveyi, multiple
signaling pathways are integrated into a single phosphorylation-
dephosphorylation cycle (PdPC). Through mathematical modeling, we will
explore how QS uses feedback loops to `decode' the integrated signals
by actively changing the sensitivity in different pathways.

## Fun Fluid Facts

Nathan WillisI will present several classical fluid problems that
demonstrate interesting and possibly unexpected phenomena. For each
example we will watch an experiment and I will provide minimal
explanation and analysis to justify the observed phenomenon. Among the
examples presented will be the Weissenberg Effect and the fact that
Stokes flow is time reversible. No expected knowledge passed calculus
and differential equations is necessary.

## Cold Fusion: Utah's (Academic) Scandal of the Century

Cody FitzgeraldIn 1989, Professor Stanley Pons was the Chairman of the
University of Utah Chemistry Department. His research on cold fusion
created one of the largest scandals in university history. This talk
will trace the history of Stanley Pons, the Fleischmann-Pons
experiment, and the international fallout that ensued.

## The Mathematics Of Dating

Rebekah EichbergPopular dating apps such as OkCupid, Tinder and Bumble
promise to use an algorithm to help suggest people we could potentially
date. Have you ever wondered how this works? Or why it doesn’t seem to
work for you? In this talk, I will give an overview on the underlying
algorithms of these apps. Hopefully, we will understand how the
algorithms work and in particular, whether there is math involved, and
whether they help us find “the one”. Please come with ideas and
opinions — anecdotes are also welcome!

## Paradoxes of Probability and Belief

Sean GroathouseProbability is often not intuitive, and even seemingly simple
questions can become paradoxical. We will explore a few paradoxes bout
probability and knowledge, hopefully bewildering ourselves a bit along
the way. After we get some practice, we will attempt to resolve a
paradox about probability and belief that continues to spark debate
today. No background in probability is necessary.