**The following list of MAA MathFest 2020 Invited Address Speakers is updated as information becomes available. Please continue checking here in the weeks ahead for further information, details, and updates.**

**Note:** All presentations except Student Activity Speaker will be in Grand Ballroom Salon G & H of the Philadelphia Marriott Downtown

*Lecture 1: Thursday July 30, 11:00 a.m. - 11:50 a.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

Lecture 2: Friday, July 31, 10:20 a.m. - 11:10 a.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H

Lecture 3: Saturday, Aug 1, 10:00 a.m. - 10:50 a.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H

### Lecture Title and Abstract TBA

**Jordan Ellenberg**, *University of Wisconsin-Madison*

### Lecture Title and Abstract TBA

*Thursday, July 30, 9:00 a.m. - 9:50 a.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

**Sommer Gentry**, *US Naval Academy*

### Increasing the Rate of Change: The Impact of Broadening the Visibility of Mathematicians of Color

*Friday, July 31, 11:20 a.m. - 12:10 p.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

**Candice Price**, *University of San Diego*

##### Abstract

African Americans, American Indians/Alaska Natives, and Latinx-- who have historically comprised a minority of the U.S. population-- are growing in size and influence. Currently, while constituting 30 percent of the U.S. population, by 2050, these groups together will account for greater than 40 percent of the U.S. population. Yet, these groups are largely underrepresented in the STEM fields---especially mathematics. Lately, there has been a growing discussion around the issue of the lack of diversity in STEM and its effect on the growth and innovation needed in these disciplines to solve the most complex issues humanity faces. I believe one reason people of color are underrepresented in STEM is that students of color rarely see themselves reflected in the STEM community. My service mission is to support those underrepresented in STEM by creating and supporting programs that increase visibility and amplify the voices of women and people of color in STEM while creating networks and community in STEM to provide opportunities to share resources. In this talk, I will describe my path in mathematics through an exploration of my involvement in programs that are working towards broadening the visibility of mathematicians of color.

##### Biography

Candice Renee Price is an African-American mathematician and assistant professor at Smith College. Born and raised in California, Candice has a bachelor’s degree (2003) in Mathematics from California State University, Chico and a master's degree (2007) from San Francisco State University. She earned her doctoral degree (2012) in mathematics from the University of Iowa under the advisement of Isabel Darcy. Her main area of mathematical research is DNA topology, that is, knot theory applied to the structure of DNA but has interests in applications of mathematics to Biology and the Social Sciences. Candice is an advocate for greater representation of women and people of color in the STEM fields.

### Lecture Title and Abstract TBA

*Saturday, August 1, 11:00 a.m. - 11:50 a.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

**Po-Shen Loh**, *Carnegie Melon University*

### Eigenvalues and Graphs

*Thursday, July 29, 10:00 a.m. - 10:50 a.m.,Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

**Steven Butler**, *Iowa State University*

##### Abstract

One way to store information about a graph is by an array with entries indexed by pairs of vertices with each entry giving information about a relationship between the pair. The linear algebraist in us would say, ``let's change our names and instead of calling it an array, let us call it a matrix, which is an array with benefits''. Among these benefits are the eigenvalues and singular values of the matrix. The eigenvalues give information about the linear transformation to which the matrix corresponds, and this can capture some structural properties of the graph (often with just knowing a few of the extremal eigenvalues). This provides a way to obtain information about a graph with just a handful of parameters. We will explore several different possible matrices and look at some of the information that we can, and in some cases cannot, learn by studying the eigenvalues.

##### Biography

Steve Butler is the Barbara J Janson Professor of Mathematics at Iowa State University. He earned his PhD degree in 2011 from UC San Diego where he studied spectral graph theory under Fan Chung. He has worked extensively with Ron Graham, and is (currently) the last person to get an Erdos number of one. He has published over 70 papers in mathematics in topics ranging from circle packings and permutation enumeration to origami and card shuffling; has performed at the Iowa State Fair; and is co-author on the forthcoming book "Juggling Counts". More information about his research and teaching is at MathButler.org.

### Data Skills for the Mathematical Sciences

*Friday July 31, 1:30 p.m. - 2:20 p.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

**Chad Topaz**, *Williams College*

##### Abstract

Data acquisition, exploration, analysis, modeling, and visualization have become central to the mathematical sciences. The importance of data has been emphasized at the highest levels of our profession, including in reports from the National Academy of Sciences, the Mathematical Association of America, the Society for Industrial and Applied Mathematics, and the American Statistical Association. However, the fusion of data skills with core parts of the mathematical sciences curriculum has yet to be fully realized. This talk discusses the importance of data skills and presents pathways for incorporating them into undergraduate mathematical sciences education. One pathway is through the classroom. I will present selected examples from courses in linear algebra, differential equations, mathematical modeling, and even calculus, including signal processing, dynamical systems, abstract art, and an interactive activity on multivariable quadrature motivated by environmental science. A second pathway is through undergraduate research. I will showcase data-intensive student projects that apply mathematics to collective motion in biology and to social justice. Finally, I will mention resources for instructors who themselves want to grow their data skills.

### Stories About How I Got Where I Am Today

*Thursday, July 29, 1:30 p.m. - 2:20 p.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

**Erica Flapan**, *Pomona College*

##### Abstract

I will talk about my life, from elementary school to becoming the Editor in Chief of the Notices of the American Mathematical Society. While my history is quite different from that of most mathematicians, I hope that hearing stories about my trials and tribulations can inspire young mathematicians facing their own trials and tribulations to keep at it as I did and become mathematicians who can then tell their own stories to the next generation of young mathematicians. This talk will include a little bit of knot theory, a little bit of spatial graph theory, a little bit of chemistry, and a little bit of humor. But mostly, it will just be stories.

### Arithmetic and Digits

*Wednesday, July 29, 8:00 p.m. - 8:50 p.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

**Florian Luca**, *University of the Witwatersrand*

##### Abstract

In our recent paper in the Monthly (October, 2019) with Pante Stănică, we looked at perfect squares which arise when concatenating two consecutive positive integers like 183184 = 428^{2} with the smaller number to the left, or 98029801 = 9901^{2} with the larger number to the left. My talk will present variations on this topic with the aim of providing the audience with examples of numbers which are both arithmetically interesting (like perfect squares) while their digital representations obey some regular patterns. The examples will not be limited to perfect squares, but will also include other old friends like Fibonacci numbers and palindromes.

### Complex Functions, Mesh Generation, and Hidden Figures in the NIST Digital Library of Mathematical Functions

*Thursday, July 30, 2:30 p.m. - 3:20 p.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

**Bonita V. Saunders**, *National Institute of Standards and Technology*

##### Abstract

In 2010, the National Institute of Standards and Technology (NIST) launched the Digital Library of Mathematical Functions (DLMF), a free online compendium of definitions, recurrence relations, differential equations, and other crucial information about mathematical functions useful to researchers working in application areas in the mathematical and physical sciences. Although the DLMF replaces the widely cited National Bureau of Standards (NBS) Handbook of Mathematical Functions commonly known as Abramowitz and Stegun (A&S), it is far beyond a book on the web, incorporating web tools and technologies for accessing, rendering, and searching math and graphics content. I will discuss some interesting historical tidbits, but then focus on past and present technical research challenges being tackled to develop the DLMF’s graphics content. The DLMF currently contains more than 600 2D and 3D figures, and over 200 interactive 3D web visualizations of high level mathematical function surfaces that users can explore.

### 2020 Census, Lagrange's Identity, and Apportionment of the U.S. House of Representatives

*Friday, July 31, 4:00 p.m. - 4:50 p.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

**Tommy Wright**, *U.S. Bureau of the Census*

##### Abstract

Given the impracticality of a pure democracy, the U.S. Constitution (1787) calls for a representative form of democracy where the people elect persons to represent them for governing. Each state gets a number of representatives in the U.S. House of Representatives "...according to their respective numbers..." as recorded in a census of the nation to be conducted every ten years starting in 1790. We make use of an elementary result known as Lagrange's Identity to provide a bridge between an insightful motivation and an elementary derivation of the method of equal proportions. The method of equal proportions is the current method for apportioning the 435 seats in the U.S. House of Representatives among the 50 states, following each decennial census. We highlight why the numbers from the census matter and affect our condition and behavior. We also present some historical comments about the first two methods of apportionment, as well as the method that preceded equal proportions.

##### Biography

Since joining the U.S. Census Bureau in January 1996 as a research mathematical statistician, Tommy Wright has provided the overall technical leadership for the Center for Statistical Research & Methodology (CSRM) (formerly Statistical Research Division) which is the Census Bureau's statistical and methodological research and collaborative/consulting facility. CSRM researchers are engaged in collaborative work applying known statistical methods and in research for new and better statistical methods motivated by practical problems encountered in measuring and releasing data on the behavior and condition of the nation's people, places, and businesses.

Between 1979 and 1996, he was a research staff member of the Mathematical Sciences Section at Oak Ridge National Laboratory (ORNL) where his collaborative research focused on probability sampling and the design of sample surveys for large energy related national studies sponsored by many different government agencies.

Tommy has over 35 years of undergraduate/graduate teaching experience in statistics and mathematics at Knoxville College; University of Tennessee-Oak Ridge Graduate Program; University of Tennessee, Knoxville; and most recently Georgetown University as adjunct faculty since 2009. He was an ASA/NSF/Census Research Fellow (1993-1996) pursuing research into using probability sampling methods to improve the constitutionally required decennial census count.

At the Census Bureau, he is currently engaged in the consideration of several problems, including: expressing uncertainty in overall rankings based on sample surveys; assessing the variability in census counts treated by a disclosure avoidance algorithm; and thinking about a role for big data with official government statistics.

Some recent results bring together his interests in optimal sample allocation, apportionment of the U.S. House of Representatives, and Lagrange's Identity.

Tommy was born and grew up in Birmingham, Alabama. He received the M.S. and Ph.D. in statistics from The Ohio State University, the M.S. in mathematics from the University of Tennessee, and the B.S. in mathematics from Knoxville College. His contributions in collaborative research, teaching, and service have led to professional recognition: (1) Elected Member, International Statistical Institute (1989) and (2) Fellow, American Statistical Association (1995).

### The Road to 2002 Sonic Boom Demonstrator

*Saturday, August 1, 9:00 a.m. - 9:50 a.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

**Christine Darden**, *Retired from NASA Langley Research Center*

##### Abstract

I will open the lecture with some explanation of my childhood, my elementary school education in a segregated school that taught no higher mathematics classes than Algebra and Plane Geometry, and my experience in Plane Geometry during 11th grade at a boarding school that also taught no higher math class. During that 11th grade experience, I fell in love with the class and decided that I wanted to be a mathematician. After high school graduation, I enrolled in a college where all of the students who were planning to become mathematicians had taken Calculus and Trigonometry in high school. I will then share how 5 years after graduating with a B.S. Degree in Math and Physics Education and after having taught high school mathematics & physics for 2 years and having earned a master’s degree in Applied Mathematics, I was hired by NASA as a Data Analyst (Computer) where I worked for 5 years supporting Engineers in the Apollo Program.The year was now 1972 and the United States has just cancelled its Commercial Supersonic Transport Program because of the noise of the sonic boom. I was transferred to a section created to work on the softening of the sonic boom of a supersonic airplane. I will then explain the process of the sonic boom work that resulted in a demonstration of the softened sonic boom.

##### Biography

Christine Mann Darden is a native of Monroe, NC and a graduate of Allen High School in Asheville, NC. She has a BS Degree in Mathematics from Hampton Institute (now University) in Hampton, VA, the MS Degree in Applied Mathematics from Virginia State College (now University) in Petersburg, VA, and the D.Sc. Degree in Mechanical Engineering from George Washington University in Washington, DC. Darden also holds a Certificate of Advanced Study in Management from Simmons College Graduate School of Management in Boston, MA.

After nearly 40 years of service, Dr. Darden retired from NASA Langley Research Center in March 2007 as a member of Senior Executive Service. Her final assignment at Langley was as Director of the Office of Strategic Communications and Education (OSCE). In that position she was responsible for the Center’s external and internal communications, community outreach, governmental relations and educational outreach. Prior to the OSCE position, which Darden assumed in October 2004, Darden served as the Langley Assistant Director for Planning, responsible for the Langley strategic planning process, and oversight of the Center’s delivery on commitments. Darden also previously served as Director of the Aero Performing Center Program Management Office (APCPMO), as a Senior Program Manager in NASA's High Speed Research (HSR) Program Office, and for nearly 30 years as an internationally known researcher in high-speed aerodynamics and sonic boom research. Prior to her NASA career, Darden served as a Mathematics Instructor at Virginia State College and taught high school mathematics.

Darden is a current or former member of several professional or honorary societies, including: Past National Secretary of the National Technical Association, Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA), Past Secretary of the AIAA Technical Committee on Aero-Acoustics, Beta Kappa Chi National Scientific Honor Society, Kappa Mu Epsilon Honorary Mathematics Society, Alpha Kappa Mu Honor Society, Sigma Pi Sigma Physics Society, and Kappa Delta Pi Educational Honor Society.

During her NASA career, Darden authored over 57 technical papers and articles, primarily in the areas of sonic boom prediction, sonic boom minimization, and supersonic wing design. She is recognized as a international expert in these areas. Darden has been recognized with dozens of awards and honors—including two NASA Medals, the Black Engineer of the Year Outstanding Achievement in Government Award and the Women in Science & Engineering Lifetime Achievement Award. One of Darden’s NASA Medals was for her active involvement in working with and encouraging students to pursue careers in math and science. Darden is also the recipient of 4 Honorary Doctorate Degrees---- Old Dominion University (’12), Muskingum University (’18), N.C. State University (’18), and George Washington University (‘2019). She was inducted into the Engineering Hall of Fame at George Washington University in 2017.

In 2016, Darden was included in the NY Times Best Seller, “Hidden Figures,” by Margot Lee Shetterly. She, and Walter, her husband of 56 years, have 3 daughters, 5 grandchildren, and 3 great-grand children.

### Surprising Discoveries by Three Amateur Mathematicians

*Saturday, August 1, 2:00 p.m. - 2:50 p.m., Philadelphia Marriott Downtown, Grand Ballroom Salon G&H*

**Doris Schattschneider**, *Professor Emerita of Mathematics, Moravian College*

##### Abstract

It is amazing how intense curiosity and ingenuity can propel persons with little or no higher mathematical training to investigate mathematical problems and make surprising discoveries. Dutch graphic artist M.C. Escher (1898-1972), a failure at school mathematics, found answers to the question “Characterize shapes that will tile the plane in such a way that every tile is surrounded in the same manner.” American homemaker Marjorie Rice (1923-2017), not allowed any math beyond a high school general math course, found new answers to the question “Characterize convex pentagons that can tile the plane.” And Dutch sculptor Rinus Roelofs (b. 1954), with an undergraduate degree in applied mathematics and a degree from AKI School of Arts, discovered a new infinite family of uniform polyhedra through sculptural exploration. This lecture will give glimpses of how these three each asked and answered mathematical questions in their own unique way.

### We Begin with a Deck of Cards …

*Friday, July 31, 1:30 p.m. - 2:20 p.m., Philadelphia Marriott Downtown, Grand Ballroom A & B*

**Robert Vallin**, *Lamar University*

##### Abstract

We all know there are lots of fun games and activities that come from a standard deck of cards. As they say during 3 a.m. infomercials, “But wait, there’s more!!” A deck is also the gateway to a myriad of different ideas in mathematics. In this event we start with some of the more straightforward ideas like counting and then move on to some other fun things that we can play with. If you have a deck of cards, bring it along (there will be a limited supply available at the session).

##### Biography

Robert Vallin earned his PhD from North Carolina State University in 1991, studying classical real analysis. Since then he has gone on to publish in analysis, topology, number theory (accidentally), and several other topics. Several years ago he took a minicourse in mathematical card magic and became hooked on recreational mathematics. He is founder and chair of the SIGMAA on Recreational Mathematics and involved in both the Gathering for Gardner and the MOVES (Mathematics of Various Entertaining Subjects) conferences. He is currently a professor at Lamar University in Beaumont, TX, where he has learned to really dislike hurricanes.