I have also worked on affine Schubert calculus and algebraic approaches using semigroup theory to Markov chains. Recently, with Brauner, Corteel and Daugherty, I have developed the new theory of crystal skeletons which provide a representation theoretic foundation for quasisymmetric functions.
I am especially fond of understanding relations between
different areas in mathematics and mathematical physics.
Often this helps to unravel hard problems in one area by
exploiting the techniques of another area. I have also contributed to
the open-source computer package Sage
through Sage-Combinat
by implementing crystal bases and Kirillov-Reshetikhin crystals
(I previously contributed to MuPAD-Combinat).
If you want to learn more on how to use crystals in Sage, there is a thematic tutorial on
Lie methods and related combinatorics
written in collaboration with Dan Bump from Stanford.
(Parabolic) quantum Bruhat graphs for A2 and A3 with J={1}
Hook-valued tableau uncrowding and tableau switching with Jihyeug Jang, Jang Soo Kim, Jianping Pan, Joseph Pappe
SIAM J. Discrete Mathematics40 (1) (2026) 32-51 ( arXiv:2410.18343 )
A hidden symmetry of refined canonical stable Grothendieck polynomials with Jihyeug Jang, Jang Soo Kim, Jianping Pan, Joseph Pappe
Seminaire Lotharingien de Combinatoire93B (2025) #18, 12pp
Decidability of Krohn-Rhodes complexity for all finite semigroups and automata with Stuart Margolis, John Rhodes
preprint arXiv:2406.18477
From quasi-symmetric to Schur expansions with applications to symmetric chain decompositions and plethysm with Rosa Orellana, Franco Saliola, Mike Zabrocki
Electronic J. Comb.31(4) (2024) #P4.23 ( arXiv:2404.04512 )
Dimension of splines on graphs in the case of degree two and smoothness one in two variables with Shaheen Nazir, Julianna Tymoczko
SIAM Journal on Applied Algebra and Geometry, to appear (arXiv:2309.11650)
Promotion for fans of Dyck paths with Joseph Pappe, Stephan Pfannerer, Mary Claire Simone
Seminaire Lotharingien de Combinatoire89B (2023) Article #20, 12 pp
Promotion and growth diagrams for fans of Dyck paths and vacillating tableaux with Joseph Pappe, Stephan Pfannerer, Mary Claire Simone
J. Algebra655 (2024) 1, 794-842 ( arXiv:2212.13588 )
Plethysm and the algebra of uniform block permutations with Rosa Orellana, Franco Saliola, Mike Zabrocki
Algebraic Combinatorics5 (2022) 5, 1165-1203 ( arXiv:2112:13909 )
Decidability of Krohn-Rhodes complexity c=1 of finite semigroups and automata with Stuart Margolis, John Rhodes
preprint arXiv:2110.10373
Generalized q,t-Catalan numbers with Eugene Gorsky, Graham Hawkes, Anne Schilling, Julianne Rainbolt
Algebraic Combinatorics3(4) (2020) 855-886 ( arXiv:1905.10973 )
An insertion algorithm on multiset partitions with applications to diagram algebras with Laura Colmenarejo, Rosa Orellana, Franco Saliola, Mike Zabrocki
J. Algebra557 no. 1, (2020), 97-128 ( arXiv:1905.02071 )
An insertion algorithm for diagram algebras Seminaire Lotharingien de Combinatoire84B (2020) Article #48, 12 pp
Combinatorial characterization of queer supercrystals (survey) with Maria Gillespie, Graham Hawkes, Wencin Poh
Bahar Acu et al. (eds.),
Advances in Mathematical Sciences,
Association for Women in Mathematics Series 21
Rigged configuration bijection and proof of the X=M conjecture for nonexceptional affine types with Masato Okado and Travis Scrimshaw
J. Algebra516 (2018) 1-37 ( arXiv:1707.04876 )
Crystal Bases: Representations and Combinatorics with Daniel Bump
World Scientific, 2017,
ISBN: 978-981-4733-43-4, 292pp
MAA review of the book!
Errata
A uniform model for Kirillov-Reshetikhin crystals III: Nonsymmetric Macdonald polynomials at t=0 and Demazure characters
with Cristian Lenart, Satoshi Naito, Daisuke Sagaki, Mark Shimozono
Transformation Groups22(4) (2017) 1041-1079 ( arXiv:1511.00465 [math.QA] )
Explicit description of the degree function in terms of quantum Lakshmibai-Seshadri paths
with Cristian Lenart, Satoshi Naito, Daisuke Sagaki, Mark Shimozono
Toyama Math. Journal37 (2015) 107-130
( arXiv:1504.04707 [math.QA] )
Affine charge and the k-bounded Pieri rule
with Jennifer Morse
DMCTS procFPSAC'15 (2015) 405-416
Flag Gromov-Witten invariants via crystals
with Jennifer Morse
DMTCS proc.AT (2014) 489-500
Quantum Lakshmibai-Seshadri paths and root operators
with Cristian Lenart, Satoshi Naito, Daisuke Sagaki, and Mark Shimozono
Advanced Studies in Pure Mathematics (Mathematical Society of Japan, Tokyo) 71 (2016), Schubert Calculus - Osaka 2012, pp. 267-294
( arXiv:1308.3529 [math.QA] )
A uniform model for Kirillov-Reshetikhin crystals. Extended abstract.
with Cristian Lenart, Satoshi Naito, Daisuke Sagaki, and Mark Shimozono
DMTCS procAS (2013) 25-36 ( arXiv.1211.6019 [math.QA] )
Combinatorial structure of Kirillov-Reshetikhin crystals of type D_n(1), B_n(1), A_{2n-1}(2)
J. Algebra 319 (2008) 2938-2962
( arXiv:0704.2046 [math.QA] )
Demazure structure inside Kirillov-Reshetikhin crystals
with Ghislain Fourier and Mark Shimozono
J. Algebra 309 (2007) 386-404
( math.QA/0605451 )
X=M Theorem: Fermionic formulas and rigged configurations under review
MSJ Memoirs 17 (2007) 75-104 (published by the Mathematical Society of Japan)
( math.QA/0512161 )
Virtual crystal structure on rigged configurations
Formal Power Series and Algebraic Combinatorics, San Diego, California 2006
( pdf file )
A simple introduction to crystals B^{2,s} for Kirillov-Reshetikhin modules of type D_n^{(1)}
with Philip Sternberg
in: A. Kuniba, M. Okado (Eds.), RIMS Kokyuroku 1429
"Combinatorial Aspect of Integrable Systems", to appear.
( postscript file )
Finite-dimensional crystals B^{2,s} for quantum affine algebras of type D_n^{(1)}
with Philip Sternberg
J. Alg. Combin.23 (2006) 317-354
( math.QA/0408113 )
Rigged configurations and the Bethe Ansatz
in: B. Lulek, T. Lulek and A. Wal (Eds), "Symmetry and Structural Properties
of Condensed Matter", Vol. 7, World Scientific, Singapore 2003; pp. 201-224
( math-ph/0210014 )
A crystal to rigged configuration bijection for nonexceptional affine
algebras
with Masato Okado and Mark Shimozono
"Algebraic Combinatorics and Quantum Groups", Edited by N. Jing, World Scientific (2003), 85-124
( math.QA/0203163 )
A tensor product theorem related to perfect crystals
with Masato Okado and Mark Shimozono
J. Algebra267 (2003) 212-245
( math.QA/0111288 )
q-Supernomial coefficients: From riggings to ribbons
in: MathPhys Odyssey 2001, M. Kashiwara and T. Miwa (eds.),
Birkhaeuser Boston, Cambridge, MA, 2002, pp. 437-454
( math.CO/0107214 )
Virtual crystals and fermionic formulas of type $D_{n+1}^{(2)}$,
$A_{2n}^{(2)}$, and $C_n^{(1)}$
with Masato Okado and Mark Shimozono
Representation Theory7 (2003) 101-163
( math.QA/0105017 )
Crystal bases and q-identities
with Masato Okado and Mark Shimozono
Contemp. Math. 291 (2001) 29-53
( math.QA/0104268 )
Branching formula for q-Littlewood--Richardson coefficients
with Mark Shimozono and Dennis E. White
Advances in Applied Mathematics 30 (2003) 258-272
( postscript file )
Fermionic formulas for level-restricted generalized Kostka polynomials
and coset branching functions
with Mark Shimozono
Commun. Math. Phys. 220 (2001) 105-164
( math.QA/0001114 )
New expressions for level-restricted Kostka polynomials
with Mark Shimozono
in: Formal Power Series and Algebraic Combinatorics,
D. Krob, A.A. Mikhalev, A.V. Mikhalev (eds.),
12th International conference, FPSAC'00, Moscow, Russia, June 2000,
Proceedings, Springer Verlag Berlin/Heidelberg 2000, pp. 367-378.
( postscript file )
A generalization of the $q$-Saalschütz sum and the Burge transform
with S. Ole Warnaar
in: Physical Combinatorics, M. Kashiwara and T. Miwa (eds.),
Birkhaeuser Boston, Cambridge, MA, 2000, pp. 163-183.
( math.QA/9909044 )
Conjugate Bailey pairs.
From configuration sums and fractional-level string functions to
Bailey's lemma
with S. Ole Warnaar
Contemp. Math. 297 (2002) 227-255
( math.QA/9906092 )
A bijection between Littlewood-Richardson tableaux and rigged configurations
with Anatol N. Kirillov and Mark Shimozono
Selecta Mathematica (N.S.)8 (2002) 67-135
( math.CO/9901037 )
Bosonic formula for level-restricted paths
with Mark Shimozono
Advanced Studies in Pure Mathematics 28,
Combinatorial Methods in Representation Theory (2000) 305-325
( math.QA/9812106 )
An A$_2$ Bailey lemma and Rogers-Ramanujan-type identities
with George E. Andrews and S. Ole Warnaar
J. Amer. Math. Soc.12 (1999) 677-702
( math.QA/9807125 )
Inhomogeneous lattice paths, generalized Kostka polynomials and
A$_{n-1}$ supernomials
with S. Ole Warnaar
Commun. Math. Phys.202 (1999) 359-401
( math.QA/9802111 )
Bailey flows and Bose-Fermi identities for the conformal coset
models $(A_1^{(1)})_N\times (A_1^{(1)})_{N'}/(A_1^{(1)})_{N+N'}$
with Alexander Berkovich, Barry M. McCoy, and S. Ole Warnaar
Nucl. Phys. B499 [PM] (1997) 621-649
( hep-th/9702026 )
Rogers-Schur-Ramanujan Type Identities for the $M(p,p')$
minimal models of Conformal Field Theory
with Alexander Berkovich and Barry M. McCoy
Commun. Math. Phys. 191 (1998) 325-395
( q-alg/9607020 )
A Higher-Level Bailey Lemma: Proof and Application
with S. Ole Warnaar
The Ramanujan Journal 2 (1998) 327-349
( q-alg/9607014 )
A Higher-level Bailey Lemma
with S. Ole Warnaar
Int. J. of Mod. Phys. B11 (1997) 189-195
( q-alg/9604015 )
$N=2$ Supersymmetry and Bailey Pairs
with Alexander Berkovich and Barry M. McCoy
Physica A 228 (1996) 33-62
( hep-th/9512182 )
Multinomials and Polynomial Bosonic Forms for the Branching Functions
of the $\widehat{su}(2)_M \times \widehat{su}(2)_N /
\widehat{su}(2)_{M+N}$ Conformal Coset Models
Nucl. Phys. B467 (1996) 247-271
( hep-th/9510168 )
Polynomial Fermionic Forms for the Branching Functions of the Rational
Coset Conformal Field Theories
$\widehat{su}(2)_M \times \widehat{su}(2)_N / \widehat{su}(2)_{M+N}$
Nucl. Phys. B459 (1996) 393-436
( hep-th/9508050 )
Multiplicative BRST renormalization of the $SU(2)$ Higgs model
with Peter van Nieuwenhuizen
Phys. Rev.D50 (1994) 967-970
( hep-th/9408125 )