Brant Jones

Department of Mathematics and Statistics
James Madison University
60 Bluestone Drive, MSC 1911
Harrisonburg, VA 22807

email: jones3bc (a t) jmu (d o t) edu

office: 325 Roop Hall, 540 568.3802


I am a Professor at James Madison University. I earned my Ph.D. in mathematics in 2007 from the University of Washington in Seattle and was selected for a three year postdoctoral VIGRE Fellowship at the University of California, Davis before moving to Virginia.

I've mentored 28 students majoring in math and computer science through various undergraduate research projects. In 2013, I was a visiting researcher in the semester program on Combinatorial Representation Theory at the Institute for Computational and Experimental Research in Mathematics (ICERM). In 2016, I was awarded a sabbatical semester and participated in the workshop on Polyhedral Geometry and Partition Theory at the American Institute of Mathematics (AIM). In 2019, I led a Research Experiences for Undergraduate Faculty (REUF) workshop at ICERM. In 2021, a paper I co-authored with Laura Taalman and Anthony Tongen was cited by Don Knuth in The Art of Computer Programming (volume 4, pre-fascicle 14a on bipartite matching). I have previously served as PI/co-PI for NSF grants that funded our department's summer Research Experiences for Undergraduates (REU) site from 2017 through 2023, and this site presently continues under the leadership of Alex Capaldi and David Duncan. I currently coordinate our department's William Lowell Putnam Competition team.

My research interests include games, algorithms, algebraic structures, and enumerative combinatorics, particularly as related to the representation theory of reflection groups. I frequently write computer programs to assist my mathematial work and have had a successful career outside the university in software engineering/consulting.


Teaching

Some of my previous classes include:

Nature of Mathematics (Strategy and Games) Math 103
Calculus III (Multivariable) Math 237
Stochastic Processes Math 423
Introductory Calculus Math 205, 231
Discrete Mathematics Math 245
Abstract Algebra I, II Math 430-1
Elementary Statistics Math 220
Elementary Number Theory Math 310
Advanced Linear Algebra Math 434
Discrete Structures CS/Math 227
Graph Theory and Combinatorics Math 353
Topology Math 435
Calculus I, II Math 235-6
History of Mathematics Math 415
Putnam Problem Solving Seminar Math 485


Presentations

Variations on some sequential best choice models
Colloquium talk at the University of Maryland, Baltimore County   October 22, 2021    (pandemic-era video talk)

Seeing the (game) trees for the forest
Spring MAA MD-DC-VA section meeting    April 13, 2019    (transcript)


Research

My present work frequently involves undergraduates. If you are a student interested in algorithms/programming or mathematical research, send me an email!

The library of papers is below. Collaborators marked with * are undergraduate researchers.

Integer diagonal forms for subset intersection relations   (with Joshua E. Ducey, *Lauren Engelthaler, *Jacob Gathje, *Izzy Pfaff, and *Jenna Plute)
(to appear in Algebraic Combinatorics)    math.CO/2310.09227

Strategy-indifferent games of best choice   (with Katelynn D. Kochalski, Sarah Loeb and Julia C. Walk)
Discrete Mathematics 345 (1) (2022) 112666    math.CO/2107.04872

Weighted games of best choice  
SIAM Journal on Discrete Mathematics 34 (1) (2020) 399-414    math.CO/1902.10163

Opportunity costs in the game of best choice   (with *Madeline Crews, *Kaitlyn Myers, Laura Taalman, *Michael Urbanski, and *Breeann Wilson)
Electronic Journal of Combinatorics 26 (1) (2019) P1.45    math.CO/1903.01821

Avoiding patterns and making the best choice  
Discrete Mathematics 342 (6) (2019) 1529-1545   math.CO/1812.00963

Positional strategies in games of best choice   (with *Aaron Fowlkes)
Involve, a Journal of Mathematics 12-4 (2019) 647--658    math.CO/1810.09887

Rational generating series for affine permutation pattern avoidance
Journal of Combinatorics 7 (1) (2016) 51-73    math.CO/1501.03087

Results and conjectures on simultaneous core partitions   (with Drew Armstrong and Christopher R. H. Hanusa)
European Journal of Combinatorics 41 (2014) 205-220    math.CO/1308.0572

The refined lecture hall theorem via abacus diagrams   (with *Laura Bradford, *Meredith Harris, *Alex Komarinski, *Carly Matson, and Edwin O'Shea)
The Ramanujan Journal 34 (2) (2014) 163-176    math.CO/1211.3702

Solitaire Mancala Games and the Chinese Remainder Theorem   (with Laura Taalman and Anthony Tongen)
The American Mathematical Monthly 120 (8) (2013) 706-724    math.CO/1112.3593

Permutation pattern avoidance and the Catalan triangle   (with *Derek Desantis, Rebecca Field, *Wesley Hough, *Rebecca Meissen, and *Jacob Ziefle)
Missouri Journal of Mathematical Sciences 25 (1) (2013) 50-60    preprint version

Using carry-truncated addition to analyze add-rotate-xor hash algorithms   (with Rebecca Field)
Journal of Mathematical Cryptology 7 (2) (2013) 97-110    cs.DM/1303.4448

Mask formulas for cograssmannian Kazhdan--Lusztig polynomials   (with Alexander Woo)
Annals of Combinatorics 17 (1) (2013) 151-203    math.CO/1011.1110

Abacus models for parabolic quotients of affine Weyl groups   (with Christopher R. H. Hanusa)
Journal of Algebra 361 (2012), 134-162    math.CO/1105.5333

Affine structures and a tableau model for E6 crystals   (with Anne Schilling)
Journal of Algebra 324 (9) (2010) 2512-2542    math.CO/0909.2442

The enumeration of fully commutative affine permutations   (with Christopher R. H. Hanusa)
European Journal of Combinatorics 31 (5) (2010) 1342-1359    math.CO/0907.0709

The enumeration of maximally clustered permutations   (with Hugh Denoncourt)
Annals of Combinatorics 14 (1) (2010) 65-84    math.CO/0704.3469

An explicit derivation of the Möbius function for Bruhat order  
Order 26 (4) (2009) 319-330    math.CO/0904.4472

A bijection on core partitions and a parabolic quotient of the affine symmetric group   (with Chris Berg and Monica Vazirani)
Journal of Combinatorial Theory, Series A 116 (8) (2009) 1344-1360    math.CO/0804.1380

Leading coefficients of Kazhdan--Lusztig polynomials for Deodhar elements  
Journal of Algebraic Combinatorics 29 (2) (2009) 229-260    math.CO/0711.1391

Kazhdan--Lusztig polynomials for maximally-clustered hexagon-avoiding permutations  
Journal of Algebra 322 (10) (2009) 3459-3477    math.CO/0704.3067

Embedded factor patterns for Deodhar elements in Kazhdan-Lusztig theory   (with Sara C. Billey)
Annals of Combinatorics 11 (3/4) (2007) 285-333    math.CO/0612043


Mathematical Software

Sage: I have contributed some code to sage.combinat, particularly an initial implementation of the Lenart--Postnikov alcove path model for crystals.

liberiksson: A C++ library to perform fast computations on elements of Coxeter groups, used for some of my papers on Kazhdan--Lusztig polynomials. More specifically, the code classifies the Deodhar elements of finite Coxeter groups by embedded factor containment, and verifies that the mu coefficients for Kazhdan--Lusztig polynomials associated to these elements are always 0 or 1.