# Graduate Student Advisory Committee (GSAC) Colloquium

**(**

Wednesdays (until Feb. 1), 4:35–5:35 PM, JFB B-1

Tuesdays (from Feb. 7), 4:35–5:35 PM, JWB 335

Math 6960–001

## Graduate Colloquium

Spring 2017Wednesdays (until Feb. 1), 4:35–5:35 PM, JFB B-1

Tuesdays (from Feb. 7), 4:35–5:35 PM, JWB 335

Math 6960–001

*credit hours available!*)

GSAC Home | Past Graduate Colloquia

The goal of this Colloquium is to encourage interaction among graduate students, specifically between graduate students who are actively researching a problem and those who have not yet started their research. Speakers will discuss their research or a related introductory topic on a level which should be accessible to nonspecialists. The discussions will be geared toward graduate students in the beginning of their program, but all are invited to attend. This invitation explicitly includes undergraduate students.

## Grad Student Forum Regarding Teaching

Kelly MacArthurThis will be an open dialogue for me to hear your feedback, concerns, questions, etc. regarding the teaching requirements as part of your PhD program in our department. I'm very interested in knowing your opinions about what is/is not working and to know how you think we might improve things going forward, as well as answer any questions you have about why we do things the way we do (assuming I know 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 my box anonymously.

## Rational approximation from dynamical systems

Leonard CarapezzaSuppose you want to arrange leaves around a stalk with equal angle between each so as to minimize overlap. What angle is best? Investigating this question naturally leads one to consider continued fraction expansions and one eventually sees that the answer involves the Fibonacci sequence and the golden ratio. In this talk I will introduce some basic concepts from ergodic theory and show how they can be applied in this situation.

## Games of No Chance

Derrick WigglesworthIn this talk, I'll introduce the basics of combinatorial game theory. Together, we'll find a winning strategy for a classical game. Then we'll discuss the Sprague-Grundy Theorem and some more difficult games. Finally, we'll end with some open problems and fun results from this subject.

## Understanding Discrimination Policies

TBASomeone from Office of Equal Opportunity and Affirmative Action will come and give a short training about information related to discrimination, sexual harassment, and the Americans with Disabilities Act (ADA). This will include important information on reporting obligations and Title IX. They will also discuss freedom of speech and what we can and cannot say in our classrooms and to students as employees of the University of Utah. This is information we should all know in order to best serve our students and to ensure we create a safe environment in our classrooms for students to flourish and learn.

## Estimating Utah's Gender Gap in Wages

Curtis MillerIn 2015, Utah had the fourth largest gender gap in wages in the country; among full-time year-round workers, women nationally earned $0.80 per men's $1, while Utah women earned $0.71. We discuss other gender gap metrics that give a fuller story. Additionally, we discuss two econometric methods relevant to the discussion. First, Oaxaca-Blinder (OB) decomposition allows us to separate the wage gap into an "endowment effect" (based on differences in individual characteristics) and a "treatment effect" (based on being paid differently for the "same" work). Second, Heckman regression allows us to handle selection bias and thus obtain regression results that apply to the actual population of interest: "all" women (not just working women). We discuss some of the theory behind these methods and apply them to Utah to see to why Utah's wage gap is large and closing slowly.

## Sorting and Indexing in Oracle

Prem NarayananManaging big data sets requires one of the most common operations in a database - sorting. Most SQL statements either implicitly or explicitly use sorts. Oracle uses a sort algorithm that claims significantly improved performance of in-database sorts since 10g-Rel2 (2010) Indexes provide faster access to data for operations, but can be costly if not managed properly.It is important to determine an appropriate storage and index optimization strategy. We will look at the sort algorithm and ways to improve performance by letting the Oracle Cost-Based Optimizer (CBO) do its job.

## Dr. SchrÃ¶dinger's Cat in the Hat

Matteo AltavillaQuantum Mechanics was born in the 1920's and to this day it is still one of the most fascinating and mysterious-looking theories of modern physics. In this talk we will briefly go over the historical motivation that led to the development of this theory, its mathematical formalization with the use of the -at the time - brand new concepts of Hilbert spaces and self-adjoint operators, and the tangible meaning of its results. SchrÃ¶dinger's cat will (and will not) make its appearance.

## Implicit Bias Workshop

Mary Anne BerzinsAt this event, Mary Anne Berzins will present an interactive workshop on understanding and mitigating implicit bias. Berzins is the Assistant Vice President of Workforce Planning for Human Resources at the University of Utah, and she was awarded in 2015 with the Linda K. Amos Award for Distinguished Service to Women.

## Topological Data Analysis: A new frontier (for sheaves)

Adam BrownTopological Data Analysis (TDA) is an emerging field of applied math which aims to study the "shape" of point cloud data sets. Many of the foundational successes of TDA were attained by adapting the abstract theory of topology to the realm of data and computation. In this talk we will describe how we can adapt the topological principle of homology to study point clouds. We will conclude with an exploration of new directions of research in TDA. In particular, we will consider potential applications of sheaf theory to computational data analysis and the role of local homology transfer in stratification learning. This talk will aim to give an intuitive introduction to the subject, and no prior knowledge of algebraic topology will be required.

## Understanding the Sphere and Hyperbolic Plane From Our Knowledge of Euclidean Space

Elizabeth WinkelmanWe will use our familiarity with Euclidean space to understand the sphere and hyperbolic plane. We can construct 3-dimensional models of these spaces by using a tiling with pieces of Euclidean space. We can also project the sphere and hyperbolic plane to the real plane, allowing us to view them on a sheet of paper (or other flat surface). We will finish by looking at some tessellations of the plane and at the series of wood engravings Circle Limit I-IV by M.C. Escher which give a tiling of the hyperbolic plane.

Accompanying slides

## Writing Effective Letters of Recommendation

Amy WildermuthThis seminar is designed to help you think about what you should consider when you are asked to write a letter of recommendation. This includes ensuring that you have all the information you need to make a good decision about when you agree to write a letter as well as reflecting on what the language you use in a letter conveys, with a particular focus on avoiding the use of gendered and other stereotypical language. *Special time: 4-5:30pm

## Randomly switching dynamical systems: analysis and behavior

Sean LawleySeveral recent biological models involve randomly switching dynamical systems. Examples include ODEs with randomly switching righthand sides and PDEs or SDEs with randomly switching boundary conditions. In this talk, I will describe the tools for analyzing these systems and highlight the interesting behavior that they can exhibit. The talk will be accessible to a broad audience of mathematics students.

## Micro Talks

VariousNine mathematicians will have no more than five minutes to present their research as thoroughly and accessibly as possible. Topics will run the gamut from pure math, math biology, and other applied math topics. Knowledge of calculus and analytic thinking are required.