Ann Trenk

Lewis Atterbury Stimson Professor in Mathematics

Research specialty in graph theory and partially ordered sets, teaches across the mathematics curriculum, outreach to K-12 teachers.

My areas of specialty are graph theory and partially ordered sets (posets). While my work is chiefly theoretical, I choose research problems that arise in modeling real world phenomena.

In graph theory I study structured families of graphs, including interval graphs, perfect graphs, and tolerance graphs. These families arise in applications and have the advantage that certain optimization problems have efficient solutions when restricted to these graphs. My work in this area culminated in the book, Tolerance Graphs, coauthored with Martin Golumbic and published by Cambridge University Press.

More recently I have worked on the distinguishing chromatic number of a graph. This subject is part of graph coloring and uses results from abstract algebra. I also study posets and, together with coauthors, initiated the study of weak and linear discrepancy. In this work we are motivated by wanting to assign integer ranks to elements of a partially ordered set so that certain fairness conditions are satisfied.

I enjoy teaching courses at all levels of the mathematics curriculum and guiding students as they progress through increasingly more sophisticated mathematics. The courses I teach most often are Calculus I and II, Linear Algebra, Number Theory, Combinatorics and Graph Theory, Abstract Algebra, Graph Theory, and a topics course in Advanced Combinatorics.

I have served on committees for several of the mathematics societies: The Association for Women in Mathematics (AWM), the Mathematical Association of America (MAA), the American Mathematical Society (AMS), and the Society for Industrial and Applied Mathematics (SIAM). I try to take turns so that I am not on too many committees at once. In recent years I have taught a two-day seminar on either graph theory or combinatorics for K-12 teachers through the Teachers as Scholars program.

I am addicted to my daily exercise and particularly enjoy running with my women science professors running group. I also love swimming and pilates and spending time with friends and family.

Link to Personal Page


  • A.B., Harvard University
  • M.S., Johns Hopkins University
  • Ph.D., Johns Hopkins University

Current and upcoming courses

  • Combinatorics is the art of counting possibilities: for instance, how many different ways are there to distribute 20 apples to 10 kids? Graph theory is the study of connected networks of objects. Both have important applications to many areas of mathematics and computer science. The course will be taught emphasizing creative problem-solving as well as methods of proof, such as proof by contradiction and induction. Topics include: selections and arrangements, generating functions, recurrence relations, graph coloring, Hamiltonian and Eulerian circuits, and trees.