# Robbie Angarone

Here I am talking about total positivity at UMN's Student Combinatorics and Algebra Seminar.

My name is Robert Angarone, but you can call me Robbie.

I'm a third-year PhD student in the school of mathematics at the University of Minnesota. My advisor is Pasha Pylyavskyy. My primary research interest is algebraic combinatorics. I especially enjoy representation theory, symmetric functions, total positivity, matroids, and unimodal/log-concave sequences.

Before coming to Minnesota, I majored in math and philosophy at Macalester College. While there, I wrote an honors thesis concerning some objects in bijection with totally symmetric self-complementary plane partitions. Andrew Beveridge was my advisor.

My email is angar017 (at) umn (dot) edu.

# Activities

In Winter 2023, I participated in the Workshop on Matroids and Tropical Combinatorics in London; I also gave a presentation there.

In Fall 2022, I passed my preliminary oral exam with a presentation titled "Weakly Interlacing Polynomials and Total Nonnegativity."

In Summer 2022, I participated in the Summer School in Algebraic Combinatorics in Kraków. I also helped to organize a combinatorics research workshop with fellow graduate students Sylvester Zhang and Trevor Karn.

Last school year (2021-2022), I helped to organize UMN's Student Combinatorics and Algebra Seminar. The current website is here.

# Teaching and Mentorship

This semester (Spring 2023), I am a TA for MATH 1051: Precalculus I and MATH 1031: College Algebra and Probability. If you are a student in one of these courses, please see our course Canvas page for more information.

In Fall 2022, I was the lead instructor for MATH 1051: Precalculus I. I wa salso a DRP mentor.

In Summer 2022, I was a TA for Minnesota's combinatorics REU.

In Spring 2022, I was a TA for MATH 3283W: Sequences, Series, and Foundations. I was also a DRP mentor for a project on surreal numbers in John Conway's On Numbers and Games.

In Fall 2021, I was a TA for MATH 3283W: Sequences, Series, and Foundations. I was also a DRP mentor for a project on partition theory and Rogers–Ramanujan identities.

In Spring 2021, I was a TA for MATH 1272: Calculus II.

In Fall 2020, I was a TA for MATH 1271: Calculus I.

# Talks

January, February 2023: Permutation actions on Chow rings of matroids, versions at both the UMN Combinatorics Seminar and MaTroCom. Abstract.

November 2022: Weakly Interlacing Polynomials and Total Nonnegativity, UMN preliminary oral exam presentation.

September 2022: Immanants imminent!, 5-minute expository "lightning talk" at the UMN Student Combinatorics and Algebra Seminar.

February 2022: Total positivity in three flavors, expository talk at the UMN Student Combinatorics and Algebra Seminar. Abstract.

July 2021: Characters of the infinite symmetric group and total positivity, expository talk at the UMN Student Summer Representation Theory Seminar. Abstract (scroll down to my name), notes.

April 2020: Stacking Blocks: Natural bijections via triangular families, Macalester College honors thesis defense. Slides (click 'present').

February 2020: Building Bridges: Finding natural plane partition bijections, Macalester College capstone project presentation. Slides (click 'present').

# Misc.

You might be looking for my father, Robert Angarone, or Robert Angarone (no relation), a recent college graduate from New Jersey.

I believe in (and I am doing my best to uphold) the axioms enumerated by Federico Ardila. I signed Math Boycotts Police.

I'm a music-lover, audiophile, and (formerly) a radio host. Some of my favorite artists are Charles Mingus, Kate Bush, and Sweet Trip.

I am in the process of collecting every album, EP, and single (in every format) released by harpist Joanna Newsom. If you own an original CD copy of 2002's Walnut Whales, I will buy it from you.*

*For a fair price.