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# Graduate Student Seminar

**DMS Graduate Student Seminar**

Mar 22, 2023 03:00 PM

108 ACLC

Speaker:

**Colby Muir**Title : Word Representability and Hasse Diagrams

Abstract: Kitaev and Pyatkin posed several open problems regarding word representability and semi-transitive graphs during a talk in October 2022. We answer one of these problems and introduce a unique algorithm which was utilized in our solution.

This is joint work with Dr. Paul Horn (University of Denver), Dr. Andrew Owens (Widener University), and Zion Hefty (Grinnell College).

**DMS Graduate Student Seminar**

Mar 15, 2023 03:00 PM

108 ACLC

Speaker:

**Matthew Speck**Title: Determinants of Sums of Normal Matrices

Abstract: Much of the research process in pure mathematics is invisible and mysterious, involving experimentation and partial results which do not appear in published papers. The goal of this talk is to demystify the research process in the context of the following algebraic problem: Given a pair of normal matrices with prescribed eigenvalues, what can the determinant of their sum be? Marcus (1972) and de Oliveira (1982) independently conjectured bounds on this determinantal set within the complex plane. We outline the steps we took to obtain a stronger statement which gives a complete geometric description of this set as a flattened twisted permutahedron.

This is joint work with Luke Oeding.

**DMS Graduate Student Seminar**

Mar 01, 2023 03:00 PM

108 ACLC

Speaker:

**Ridvan Ozdemir**(PhD student under the guidance of Junshan Lin)Title: Topologically Protected Interface Modes in Mechanical Systems

Abstract: In this talk, we present an approach to topologically protected edge states. The study is based on breaking the inversion symmetry of a periodic media that is constructed via setting unit cells and joining periodic aggregations that are reflections of each other with respect to a unit cell or a group of cells. This construction reveals some topological structures with some dispersion topological invariants, which are Zak phase and Chern numbers in our case. We study both 1D lattice and 2D hexagonal lattice problems in topological photonic structure and existence of interface states when two sides of the system have some certain characteristics.

**DMS Graduate Student Seminar**

Feb 22, 2023 03:00 PM

108 ACLC

Speaker:

**Dr. Rob Molinari**Title: Robust and Scalable Inference for Stochastic Processes

Abstract: Stochastic processes are broadly used in many applications and fields of research going

from astronomy, engineering, and physics to healthcare and social sciences. One of the main purposes for which they are used is to obtain inference on parameters, interpretable predictions, and reliable uncertainty quantification. Their use is however challenged by the growing size of data and the presence of different forms of contamination in parts of the data (including missingness) which severely limit the use of commonly employed statistical approaches. To address this, we make use of a moment-based method built upon a wavelet-decomposition of the data where it is possible to adapt and limit the impact of these different forms of contamination while preserving reasonable computational efficiency as data scales. We present the theoretical and applied properties of this framework and discuss the ongoing extensions to different tasks of robust inference on large-scale stochastic processes.
**DMS Graduate Student Seminar**

Feb 15, 2023 03:00 PM

108 ACLC

Speaker:

**Dr. Le Chen**Title: Sharpening your saw before cutting down the tree -- Personal development environment (PDE)

Abstract:

**Pursuing a Ph.D. is a major commitment that requires a lot of hard work and dedication. During this journey, students will have the opportunity to develop important skills that are essential for research, such as critical thinking, problem-solving, writing, programming, time management, collaboration, and communication. In addition to these skills, I would encourage students to take the time to develop their personal development environment (PDE) and refine their optimal workflow. To help with this, I will showcase some useful tools such as a text editor (e.g., Neovim), AI tools like ChatGPT and Github Copilot, and various utilities that can automate your workflow and do your research and teaching more efficiently.****DMS Graduate Student Seminar**

Feb 08, 2023 03:00 PM

108 ACLC

Speaker:

**Professor Nedret Billor**Title:

**Statistics and Data Science Programs**Abstract:

**In this seminar, we introduce Statistics and Data Science programs and my research areas, specifically focusing on the Data Science program and its backbone, Capstone Project Course. We give information on how this course is run and present a sample of the past project descriptions. We explain how graduate students can benefit from taking this course.****DMS Graduate Student Seminar**

Feb 01, 2023 03:00 PM

108 ACLC

Speaker:

**Eric Harshbarger**Title: Latest Improvements on "Go First Dice"

Abstract: This talk will focus on the history of the "Go First Dice" problem and highlight improvements that have been made in the past two months.

**DMS Graduate Student Seminar**

Jan 25, 2023 03:00 PM

108 ACLC

Speaker:

**Dr. Hannah Alpert**Title: Routing on higher-dimensional convex grid pieces

Abstract: Can you distort an arbitrary convex polygon to fit into a rectangle of about the same area, without stretching or squishing it too much? This question is open in the precise formulation I have in mind, and I hope you will be inspired to solve it. It comes from my students' REU project about routing tokens on graphs, which comes from my research about topology of configuration spaces of disks. We'll talk about how one question leads to another.

**DMS Graduate Student Seminar**

Jan 18, 2023 03:00 PM

108 ACLC

Speaker:

**Dr. Le Chen**Title: Introduction to the stochastic heat equation

Abstract: In this talk, I will delve into the intricacies of the stochastic heat equation (SHE), a mathematical model that captures the delicate balance between the smoothing effect of the Laplacian and the roughening effect of multiplicative noise. The interplay of these opposing forces can be observed in a wide range of natural phenomena. Gaining a deeper understanding of the SHE is crucial as it serves as a stepping stone to unlocking the mysteries of many more complex systems.

**DMS Graduate Student Seminar**

Nov 30, 2022 03:00 PM

108 ACLC

Speaker:

**Dr. Amy Huang**Title: An introduction to the uses of representation theory in algebraic geometry

Abstract: Algebraic geometry is a way of using the polynomial functions on an object to study its underlying geometry of it. When there is a group acting on the object of interest, it is often useful to use the representation theory of the group to simplify the study. In this talk, I will use the twisted cubic as an example. We will dig into the syzygy of its coordinate ring and how the representation theory helps us visualize it.

Last Updated: 09/11/2015