Author: Samuel Gutekunst

The Mathematics Department’s Distinguished Visiting Professor

Dan Timotin, Institute of Mathematics of the Romanian Academy

Tuesday, April 26th 4:00 P.M.
ROOM 372 in the Olin Science Building

Abstract: If A and B are self-adjoint matrices, what is the relation between the eigenvalues of A, those of B, and those of A+B? The talk will describe the unexpected ramifications in various areas of mathematics of this old problem. Some recent developments, mostly pertaining to operator theory, will also be presented.

HONORS THESIS DEFENSE

Contraction-based approach to tensor isomorphism

Presented by:

Anh Kieu ‘22

Thesis Advisor: Pete Brooksbank

2^nd Reader: Ben Vollmayr-Lee
Wednesday, April 20, at 4:00 PM
OLIN 372

Everyone is welcome to attend.

Abstract: Tensors are natural generalizations of linear transformations to arbitrary “frames” of vector spaces. Just as how a linear transformation can be represented by a matrix, choosing a reference frame allows a tensor to be represented by a multiway array. A fundamental question is to decide when two multiway arrays represent the same tensor relative to different reference frames. This question is commonly known as the tensor isomorphism problem. In this Honors Thesis, we developed a new approach to testing (non)-isomorphism of tensors that uses detailed local information to detect differences in global tensor structure. The method assumes isomorphism invariant “labels” for lower valence tensors can be computed, and then compares two given tensors by computing their so-called “contraction labels.” We implemented this method in a computer algebra system called Magma and applied it to 4-qubit states in QIT as a proof of concept.

Mathematics Department, Student Colloquium Series

MASKS REQUIRED

PIZZA SERVED from 11:30 -11:55 in front of Hislop Family Auditorium

TALK STARTS AT 12:00 PM

“Lies, Damn Lies, and…Olympic Judging Systems”

Presented by

John W. Emerson
Director of Graduate Studies
 Department of Statistics and Data Science – Yale University

Thursday, April 21, 2022

12:00 P.M.        HOLMES HALL – 116 Hislop Family Auditorium

Abstract: This talk considers aspects of Olympic judging systems in two different sports, diving and figure skating.  The former sport can boast of complete transparency, with the identities of the judges tied to scores available to the general public.  The latter sport, in contrast, has struggled to evolve since the judging scandal of the Salt Lake City Olympic Games.

BIO: John W. Emerson is the Director of Graduate Studies in the Department of Statistics and Data Science. His primary interests are in computational statistics and graphics, and his applied work ranges from topics in sports statistics to bioinformatics, environmental statistics, and Big Data challenges. He teaches a range of undergraduate and graduate courses from “Introductory Data Analysis” to “Statistical Case Studies.” He is the author of several R packages including bcp (for Bayesian change point analysis), bigmemory and sister packages (towards a scalable solution for statistical computing with massive data), and gpairs (for generalized pairs plots). He has served in various leadership roles in several sections of the American Statistical Association.  He misses international travel and loves to cook.

Mathematics Department Student Colloquium Series

PIZZA SERVED from 11:30 -11:55    in front of Hislop Family Auditorium

TALK STARTS AT 12:00 PM

“Do I have an artifact in my data? The challenges of acquiring high fidelity data at high rates of acquisition”

Presented by

Professor Wendelin Wright – Bucknell University
Heinemann Family Professor in Engineering, and Professor of Mechanical and Chemical Engineering

Thursday, March 24, 2022

12:00 P.M.        HOLMES HALL – 116 Hislop Family Auditorium

Abstract: I have spent much of my career measuring small, fast features in mechanical test data for a class of materials known as metallic glasses. These are non-crystalline metals that show unusually high strengths and hardnesses but limited ductilities due to the occurrence of a microstructural phenomenon known as shear banding. Since understanding and manipulating shear banding is key to utilizing these materials in applications, I seek to measure shear band propagation using a variety of test techniques at rates up to 100 kHz. In this talk, I will demonstrate some of the pitfalls that can result when acquiring data if the signals are not measured using the proper instrumentation or at sufficiently high rates. I will also discuss some of the strategies we have developed to determine whether the behavior we are capturing is real.

Mathematics Department Student Colloquium Series

PIZZA SERVED from 11:30 -11:55    in front of Hislop Family Auditorium

TALK STARTS AT 12:00 PM

“Number Talks, Math Tasks, and More: Teaching School Mathematics”

Presented by

COURTNEY RICE ‘08
 Department of Mathematics – Bucknell University

Thursday, March 3, 2022

12:00 P.M.        HOLMES HALL – 116 Hislop Family Auditorium

Abstract: In this session, we’ll dive into some of the nuances of teaching school mathematics. How do you develop number sense in students? What about students with different learning styles? How much thought do teachers actually give to the math tasks they use in class? Given by a mathematics and teacher educator, expect to participate in discussion! You’ll walk out of here with a deeper appreciation and understanding of what goes into the teaching of school mathematics. 

Mathematics Department

Student Colloquium Series

PIZZA SERVED from 11:30 -11:55 in front of Hislop Family Auditorium

TALK STARTS AT 12:00 PM

“1, 2, skip a few”

Presented by

BRETT COLLINS
 Department of Mathematics – Bucknell University

Thursday, February 17, 2022

12:00 P.M.        HOLMES HALL – 116 Hislop Family Auditorium

Abstract: One of the most basic problems in mathematics is simply counting how many there are of something, such as the number of Sudoku puzzles or the number of arrangements of a Rubik’s Cube, yet this is often notoriously difficult. In this talk, I’ll show through examples how symmetry can be used in many problems like this and how we can easily generalize these ideas to more difficult counting problems. One thing that you can certainly count on is having mathematical fun.  

PIZZA SERVED from 11:30 -11:55     in front of Hislop Family Auditorium

TALK STARTS AT 12:00 PM

“Dido’s Problem and the Isoperimetric Inequality”

Presented by

CHEE HAN TAN
 Department of Mathematics – Bucknell University

Thursday, February 3, 2022

12:00 P.M.        HOLMES HALL – 116 Hislop Family Auditorium

Abstract: What is the shape with a given perimeter that encloses the largest area? In this talk, we will learn about the history of this problem (dating back to 814 BC) and daring attempts by many great mathematicians whose incomplete solutions led to the development of diverse areas in modern mathematics. Finally, we will reveal the answer and discuss how to solve the problem.  

“When the Supreme Court declares your homework unconstitutional: Reflections on data science and society”

Presented by David Hunter,  Department of Statistics – Penn State University

Thursday, January 20, 2022

12:00 P.M.        HOLMES HALL – 116 Hislop Family Auditorium

Abstract: The 2003 U.S. Supreme Court case known as Gratz v. Bollinger addresses a formula for college admissions that was created by a statistics graduate student (the presenter) for a specific purpose.  The method used to create this formula is considered simplistic by modern machine learning standards; yet the debate that ensued, which could not have happened if a more modern approach had been used, illustrates that science and society do not always benefit from machine learning models that achieve the best possible predictive performance.  This talk discusses the history of the legal case, the admissions formula and how it was created, and the implications of the debate for how we build predictive models.

PIZZA Provided!

“What Did You Do Last Summer?”, Presented by Bucknell Students

NOVEMBER 4 (Thursday) 12:10 P.M. Gardner Lecture Hall – Dana 113

Moderator: Jack de la Parra

Panelists:

Anh Kieu (pronounced like Ahn), ‘22, Software Engineering Intern, Google DeepMind

Emily Desernia ‘22, JPMorgan Chase Bank

Julia Sanger ’22, Research Experience for Undergraduates (Applied Math), Georgia Institute of Technology.

Yang Hong ’23, Undergraduate Research, Bucknell University

Jamie Falla ‘22, Risk Finance, Lockton Companies

Abstract: There are many exciting summer opportunities for students in the mathematical sciences! These range from internships in financial companies to research experiences at other universities to leadership development programs. In this week’s colloquium, a panel of your peers will tell you their experiences. What did they enjoy about their experiences? When did they apply? There will also be ample time for questions and answers. These varied opportunities, as well as being terrific fun, are also immensely valuable as you begin to think about your careers after Bucknell.