Professor of Mathematics, University of Kansas

Director of Graduate Studies, Department of Mathematics

Section Chief Editor, **Frontiers for Young
Minds, Understanding Mathematics**

- Protect KU
- City of Lawrence
- Lawrence/Douglas County Public Health
- Kansas Department of Health and Environment
- KU also maintains an emergency aid network with many resources (medical, financial, counseling, etc.)

**Mailing address:**

Department of Mathematics

University of Kansas

405 Snow Hall

1460 Jayhawk Boulevard

Lawrence, KS 66045-7594

The best way to contact me: **send e-mail** to

**Office hours for Spring 2021:** TBA

**Office:** 618 Snow (I am rarely there)

**Phone:** (785) 864-7114 (email strongly preferred)

**Department fax:** (785) 864-5255

**Teaching** |
**Research** |
**Mathematics Links** |
**Fun Stuff**

I am the Section Editor of the **Understanding Mathematics**
section of **Frontiers for Young
Minds**, an open-access journal with articles written by scientists
and reviewed by kids. We are looking for help at all levels: editors,
authors, science mentors, and of course kids to review and read articles!

I am a co-organizer of the Jayhawk Math Teachers' Circle.
** UPDATE:** JMTC is on hold indefinitely due to the coronavirus outbreak.

- Spring 2021: Math 696 (Topics in Topology), MWF 2:00-2:50pm, online synchronous
- Fall 2021: Math 724 (Combinatorial Mathematics), MWF 2:00-2:30pm, Snow 301
- Spring 2022: Math 821 (Algebraic Topology), MWF 2:00-2:50pm, Snow 301

- If I have agreed to write a
**letter of recommendation**for you, please read this page. - Resources for job seekers: MathJobs (focused more on academia); MAA Career Resource Center (focused less on academia)
- Advice on writing personal statements for graduate school
- More advice on personal statements (Prof. David Glickenstein, U. of Arizona)
- Studying for the Math GRE Subject Test (Prof. Mo Omar, Harvey Mudd)
- Undergrad math majors looking for summer research: see MathPrograms, the AMS REU list, the NSF REU list, and Steve Butler's list of REUs.
- Grad school advice: The Grad Cafe, AMS E-Mentoring Blog

My main focus of research is algebraic combinatorics. I also am interested in areas of mathematics including algebraic geometry, discrete geometry, commutative algebra, and algebraic topology. I especially like topics in which these fields intersect: simplicial and cell complexes, configuration varieties, Coxeter groups, hyperplane arrangements, Stanley-Reisner theory, matroids, Gröbner bases, and combinatorial Hopf algebras and monoids. I am always happy when combinatorial techniques can be used to solve problems from other areas of pure or applied mathematics.

- Curriculum vitae (11/12/20)
- Publications (detailed list with abstracts, talk slides, etc.) (12/10/20)
- Publications (brief list)
- Look me up on MathSciNet, the arXiv, Google Scholar, or the Math Genealogy Project.
- Recent talk slides (3/3/20)
- Source code and data for some research projects and papers

- I have developed (and am perpetually revising) a set of lecture notes for my Algebraic Combinatorics course (Math 824) (last updated 9/25/20). They are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

- Kevin Marshall
- Mark Denker
- All my past and current students

- Numerical PDE/Geometry/Topology study seminar Fall 2014
- Informal notes on the chip-firing game
- Bruno Benedetti and Frank Lutz's Library of Triangulations
- Scribe notes from an informal seminar on Stanley-Reisner theory at the University of Minnesota, Fall 2002
- The Maple worksheet from my talk to the KU Math Club on March 7, 2007 (based on the article "Harmonic algebraic curves and noncrossing partitions"
- My Erdös number is 2, via John H. Conway and this paper.

(i.e., "if you are not a professional mathematician but would like to know what all this is about"

- Some of my research, explained in plain English (perennially under construction; last updated 9/14/16)
*Amazing Patterns in the Game of Nim*(talk for middle schoolers at Emporia State, 10/25/16)*Network Flow Models*(talk at Red Hot Research on 3/28/14)*Math, Fairness and Social Choice*(talk on Science on Tap at Free State Brewing Co. on 3/25/14, sponsored by KU Natural History Museum)*The Notorious Four-Color Problem*(short course at KU Mini College 2013)*Planes, Hyperplanes and Beyond: Understanding Higher-Dimensional Spaces*(short course at KU Mini College 2012)

- American Mathematical Society
- Mathematical Association of America and its Kansas Section
- Mathematical Sciences Research Institute
- American Institute of Mathematics
- Simons Foundation
- Canada/USA Mathcamp

- The On-Line Encyclopedia of Integer Sequences
- FindStat (combinatorial statistic finder)
- MacTutor History of Mathematics archive
- Archives of American Mathematics

- Sage/CoCalc (a free, open-source, general-purpose mathematics software system)
- Macaulay2 (computational commutative algebra and algebraic geometry)
- Polymake and LattE (convex polyhedra, lattice points, finite simplicial complexes)

- arXiv.org e-Print Archive
- Mathematics on The Simpsons
- AMS Blog: On Teaching and Learning Mathematics
- The "What is..." column in Notices of the AMS

- My bridge page
- Some additional mathematics publications
- Recipes
- XL, a piece of electronic music written by me and remixed by my brother
- How not to be a thesis advisor
- What it's really like to be a graduate student
- The presumably infamous L'Hopital's Rule warning label
- A photo of me acting like a mathematician

Last updated Sat 1/16/21