I am a Reader in Pure Mathematics in
the School of
Mathematical Sciences at
University of London.
Office: 312, Maths Building, Mile End campus (number 4 on
Telephone: 020 7882 5520
he / him
Office hours: see
my entry on the School's pages. Or email for an appointment.
Here is my CV.
Teaching and tutoring
In Semester B I am teaching
MTH4104, Introduction to Algebra.
In previous years I have taught an advanced graduate module on
at the London Taught Course Centre.
I am the Director of Postgraduate Research for the School of Mathematical Sciences.
You can email me with questions about our PhD programme.
Administrative queries on admissions can also be sent to
our Postgraduate Research Programme Officer.
Diane Maclagan and Felipe Rincón and I had planned to run a workshop
titled Algebraic Geometry of Matroids
in the autumn of 2020, but
because of the coronavirus the workshop will not in fact run then.
We are working on plans to postpone the workshop to after ICMS reopens.
Some past activities organised:
I have two current PhD students:
My former students are
Zeinab Toghani was a recent postdoc of mine.
I share interests with the
Algebra and Number Theory,
Geometry and Analysis
research groups at Queen Mary. It is the Algebra and Number Theory group which I am formally affiliated with.
My research interests are principally in
algebraic combinatorics, especially where commutative algebra
or algebraic geometry apply, including
matroid theory and tropical geometry.
I have previously held EPSRC grant EP/M01245X/1
Algebra and geometry of matroids
and Horizon 2020 Marie Skłodowska-Curie grant No 792432
Tropical differential geometry.
Publications (and talk slides)
- Journal articles, conference papers, preprints
- Javier Elizondo, Alex Fink and Cristhian Garay López, Matroids and the space of torus-invariant subvarieties of the Grassmannian with given homology class,
- Laura Escobar, Alex Fink, Jenna Rajchgot and Alexander Woo, Gröbner bases, symmetric matrices, and type C Kazhdan–Lusztig varieties,
- Alex Fink and Zeinab Toghani, Initial forms and a notion of basis for tropical differential equations,
- Andrew Berget and Alex Fink, Equivariant K-theory classes of matrix orbit closures, to appear in International Mathematics Research Notices.
- Alex Fink, Karola Mészáros and Avery St. Dizier, Zero-one Schubert polynomials,
Mathematische Zeitschrift 297 no. 3 (2020), 1023–1042.
- Alex Fink and Jorge Alberto Olarte, Presentations of transversal valuated matroids, Journal of the London Mathematical Society 105 no. 1 (2022), 24–62,
- Amanda Cameron and Alex Fink, The Tutte polynomial via lattice point counting, to appear in Journal of Combinatorial Theory, Series A.
See also the FPSAC 2016 extended abstract.
- Clément Dupont, Alex Fink and Luca Moci,
Universal Tutte characters via combinatorial coalgebras,
Algebraic Combinatorics 1 no. 5 (2018), 603–651.
from his minicourse at Dobbiaco 2018.
- Alex Fink and Luca Moci,
Polytopes and parameter spaces for matroids over valuation rings,
Advances in Mathematics 343 (2019), 449–494.
- Alex Fink, Karola Mészáros and Avery St. Dizier,
Schubert polynomials as integer point transforms of generalized permutahedra,
Advances in Mathematics 332 (2018), 465–475.
- Alex Fink, David E Speyer and Alexander Woo,
A Gröbner basis for the graph of the reciprocal plane,
Journal of Commutative Algebra 12 no. 1 (2020), 77–86.
- Alex Fink, Jenna Rajchgot and Seth Sullivant,
Matrix Schubert varieties and Gaussian conditional independence models,
Journal of Algebraic Combinatorics 44 no. 4 (2016), 1009–1046.
- Andrew Berget and Alex Fink, Equivariant Chow classes
of matrix orbit closures,
Transformation Groups 22 no. 3 (2016),
- Andrew Berget and Alex Fink, Matrix orbit closures,
Beiträge zur Algebra und Geometrie 59 no. 3 (2018), 1–34,
- Alex Fink and Felipe Rincón, Stiefel tropical
linear spaces, Journal of Combinatorial Theory, Series A 135 (2015),
- Alex Fink and Luca Moci, Matroids over a ring,
Journal of the European Mathematical Society 18 issue 4 (2016), 681–731.
- Alex Fink,
expansions of matroid Stanley-Reisner rings,
- Alex Fink, Aviezri Fraenkel, Carlos Santos,
Lim is not slim,
International Journal of Game Theory 43 issue 2 (2014), 269–281.
Online at IJGT.
- Alex Fink, Lattice games without rational strategies,
Journal of Combinatorial Theory, Series A 119 (2012), 450–459.
- Alex Fink and David E Speyer, K-classes of matroids
and equivariant localization, Duke Math. J. 161 no. 14 (2012),
- Alex Fink, Tropical cycles and Chow polytopes,
Beiträge zur Algebra und Geometrie
54 no. 1 (2013), 13–40.
Online at Beiträge.
Video of the talk, MSRI, 16 October 2009.
- Harm Derksen and Alex Fink, Valuative invariants
for polymatroids, Advances in Mathematics
225 no. 4 (2010), 1840–1892.
- Alex Fink, The binomial ideal of the intersection axiom
for conditional probabilities,
J. of Algebraic Combinatorics 33 issue 3 (2011), 455–463.
- Alex Fink, Richard Nowakowski, Aaron Siegel, David Wolfe,
Toppling conjectures, Games of No Chance 4,
MSRI Publications volume 63, 65–76.
- Alex Fink and Benjamin Iriarte Giraldo,
Bijections between noncrossing and nonnesting partitions
for classical reflection groups, Portugaliae Mathematicae
67 fasc. 3 (2010), 369–401.
- Alex Fink and Richard K Guy,
The outercoarseness of the n-cube,
Contributions to Discrete Math. 12 no. 2 (2017), #582.
- Alex Fink, Richard Guy and Mark Krusemeyer,
Partitions with parts appearing at most thrice,
Contributions to Discrete Math. 3 (2008), #79.
- Federico Ardila, Alex Fink and Felipe Rincón,
Valuations for matroid polytope subdivisions,
Canadian Journal of Mathematics,
published electronically on July 29, 2010.
- Alex Fink, Jörg Denzinger, and John Aycock,
Extracting NPC behavior from Computer Games using Computer Vision
and Machine Learning Techniques, IEEE Symposium on
Computational Intelligence and Games, 2007, 24–31.
- Alex Fink and Richard Guy,
The number-pad game,
Coll. Math. J. 38 (2007), 260–264.
- Alex Fink,
A generalization of an IMO problem,
Integers, Electronic Journal of Combinatorial Number Theory
6 (2006), #A17.
- Alex Fink and Bill Sands,
Rationals whose sum equals the
reciprocal of their product, Crux Math. 30
- Doctoral thesis
- My thesis was titled
Matroid polytope subdivisions and valuations. Aside from an introduction all its content appears in the
- Expository writing, manuscripts
Matroid subdivisions, and
a computational appendix.
Written for Jack Edmonds' 2015 summer courses on
Polyhedral Combinatorics and Exponential Polytime,
of which I gave a segment.
- Alex Fink and Richard Guy,
Rick's Tricky Six Puzzle:
S5 sits specially in S6,
Math. Magazine 82 no. 2 (April, 2009). See also Doug Ensley's
interactive supplement with implementations of the puzzle.
- If two were three,
what would Hex be?, 2008,
for Gathering for Gardner 8.
See also my other page
on this game, with an implementation.
- Patulous pegboard polygons,
with Derek Kisman and Richard Guy, 2006, for Gathering for Gardner 7,
Mathematical wizardry for a Gardner, AK Peters, 2009.