David E Speyer

Contact Information:

E-mail: speyer@umich.edu

Office: 2844 East Hall

Phone (Cell): (734)-255-8610
Phone (Office): (734)-764-6897

Mail (Work):
David E Speyer
Department of Mathematics
2844 East Hall
530 Church Street
Ann Arbor, MI
48109-1043 USA
My Name:
My last name is pronounced "spire", like the top of a church. But I'll answer to "Sp-vowel-r!" or to "David!". For the curious, it is derived from the city of Speyer, Germany.

About Me:

I am an Associate Profesor in the department of mathematics at the Univeristy of Michigan. I am married, and have two kids.


I enjoy algebraic problems with a combinatorial flavor. If you started out with a well motivated algebraic question but wound up with lots of little complicated pictures, I probably want to hear about it. Some topics I can usually be relied upon to think about: tropical geometry, cluster algebras, flag manifolds and other geometry of Lie Groups, interesting degenerations of algebraic structures, exact results and asymptopics of perfect matchings (eg Arctic Circle phenomena). I also know a reasonable amount of Number Theory and enjoy talking about it, although as yet this is not a research interest.


I have recently taught calculus, linear algebra, calculus on manifolds (fall term) (winter term), algebraic geometry (fall term) (winter term), graduate algebra (mostly Galois theory), a class on the combinatorial representation theory of GLn, Hodge theory, combinatorics (mostly graph theory) and a course on perfect matchings. I am the course coordinator for Applied Linear Algebra (Math 214).

I taught a sequence of lectures on Tropical Geometry, focusing on connection to Cluster Algebras, at the Jussieu Summer School. You can read my lecture notes. Nick Proudfoot and I also organized a summer school on cluster algebras and canonical bases at U. Oregon, you can read the lecture notes and problem sets.

I am a member of the REBUILD committee, which is dedicated to improving the teaching of introductory science and mathematics courses at the University of Michigan.


My current students are Jake Levinson (higher dimensional analogues of the Mukhin-Tarasov-Varchenko theorem and K-theory of Grassmannians), Rohini Ramadas (Hurwitz spaces and connections to dynamics) and John Wiltshire-Gordon (representation stability, configuration spaces and representations of categories). My graduated students are Nic Ford (Knutson's shifting construction for positroids) and Giwan Kim (standard monomial theory and toric degenerations).

I have supervised undergraduate research projects by Jonathan Schneider, David Rush, Patrick Lenning, Andrew Getlin and Benjamin Branman.


Before coming to the University of Michigan as a professor, I was a Clay Research Fellow. In that capacity, I spent two years (2005-2007) at the University of Michigan and three (2007-2010) at MIT.

I have a Ph. D. in mathematics from UC Berkeley, where I was a student of Bernd Sturmfels. My thesis is on tropical geometry, an approach to turning algebraic geometry problems into polyhedral geometry. Before coming to Berkeley, I was an undergraduate at Harvard. While there, I worked for Jim Propp's research group REACH and wrote an undergraduate thesis on the Eichler-Shimura correspondence under William Stein. I spent the rest of my time doing theater tech, hanging out with science fiction fans and working on Les Phys — the physics musical!

I spent four years as a counselor at PROMYS, a number theory program for high school students, and highly endorse it either as a place to study or to work. I spent my own high school summers at MOP, which I found great but works better for some people than for others. I went to High School at Choate Rosemary Hall and to Middle School at Talcott Mountain Academy. If you are a young nerd in Connecticut, looking for a middle school or after school program, I highly recommend Talcott.

Recent Papers

  • The Growth Rate of Tri-Colored Sum-Free Sets with Robert Kleinberg and Will Sawin.
  • The Twist for Positroid Varieties with Greg Muller.
  • Cohomology of cluster varieties. I. Locally acyclic case with Thomas Lam.
  • Variations on a theme of Kasteleyn, with application to the totally nonnegative Grassmannian.
  • A Cambrian framework for the oriented cycle with Nathan Reading.
  • Computing Hermitian determinantal representations of hyperbolic curves with Daniel Plaumann, Rainer Sinn and Cynthia Vinzant.
  • Cambrian frameworks for cluster algebras of affine type with Nathan Reading.

    Click HERE for a complete bibliography