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

In Fall 2013, I will teach linear algebra and combinatorics. My office hours are Mondays 10 – 12 and Tuesdays 2 – 3 in my office (2844 East Hall). I am also glad to make appointments to meet with students at other times.


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 go learn or to go 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.


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.

Past Courses

I have recently taught Calculus, Linear Algebra, 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 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.

Recent Papers

  • Cluster algebras of Grassmannians are locally acyclic with Greg Muller.
  • Schubert problems with respect to osculating flags of stable rational curves Algebraic Geometry, to appear.
  • Dressians, Tropical Grassmannians and their rays with Sven Herrmann and Michael Joswig.
    Forum Mathematicum to appear.
  • Acyclic cluster algebras revisited with Hugh Thomas. Proceedings of the Abel symposium to appear.
  • Positroid Varieties: Geometry and Juggling with Allen Knutson and Thomas Lam. Compositio to appear.
  • Combinatorial frameworks for cluster algebras, with Nathan Reading.
  • Weak Separation and Plabic Graphs with Suho Oh and Alex Postnikov.

    Click HERE for a complete bibliography