Emily Peters

Assistant Professor

epeters3 (at) luc (dot) edu

My research interests are planar algebras, subfactors, fusion categories and knots. My advisor was Vaughan Jones, and my dissertation was on "A planar algebra construction of the Haagerup subfactor."

I am co-organizing the Chicago Operator algebra and Group Theory seminar

Papers and Preprints

Subfactors of index less than 5, part 2: Quadratic tangles and triple points: preprint. (Joint with Scott Morrison, David Penneys and Noah Snyder): to appear in International Journal of Mathematics

Knot polynomial identities and quantum group coincidences: preprint. (Joint with Scott Morrison and Noah Snyder): Quantum Topology, Vol.2, No.2 (2011) pp101--156.

Constructing the extended Haagerup planar algebra: preprint. (Joint with Stephen Bigelow, Scott Morrison and Noah Snyder): to appear in Acta Mathematica

A planar algebra construction of the Haagerup subfactor: International Journal of Mathematics, Vol. 21, No.8 (2010) pp987--1045.

Skein Theory for the D_{2n} planar algebra (Joint with Scott Morrison and Noah Snyder): Journal of Pure and Applied Algebra, Vol. 214, No.2 (2010) pp117--139.

I assembled some notes from "Operator Algebras and Conformal Field Theories," August 16-21 2010, University of Oregon. These notes are the result of lots of people giving great talks and other people's great liveTeXing of those talks.


My focus is on constructing planar algebras, and exotic subfactors. Planar algebras are a tool for doing certain computations by drawing pictures; more technically, a planar algebra is a structure in which certain diagrams in the plane are interpreted as morphisms. Subfactors of von Neumann algebras give an example of a planar algebra.

The simplest example of a planar algebra is the Temperley-Lieb algebra, which first arose in statistical mechanics. The planar algebra perspective on Temperley-Lieb helps explain why this algebra has close ties to both subfactors and knot theory (specifically, the Jones polynomial).

I'm particularly interested in using planar algebras to construct exotic subfactors. Exotic subfactors are those which don't come from previously studied algebraic objects, like groups, quantum groups, or rational conformal field theories. In my dissertation, I used planar algebras to construct the Haagerup subfactor, and also to find a non-standard embedding (I use this term loosely) of the Haagerup planar algebra in a graph planar algebra.

My current interests are in developing the Atlas of Subfactors, and classifying principal graphs up to small index limits (Joint with Vaughan Jones, Scott Morrison, Dave Penneys, Noah Snyder, and others), and also learning more about tensor categories. If you'd like more details, check out my NSF project proposal , read some blog posts about planar algebras, or email me!

Handouts and Slides

Planar algebras and evaluation algorithms. Slides from my talk at UW Madison, April 1, 2013.

Classifying Subfactors: beyond index 5. Slides from my talk at NCGOA 2012, Vanderbilt University, May 9, 2012.

Non-commutative galois theory and the classification of small indes subfactors. Slides from my colloquium at UMass Boston, November 30 2011.

The classification of subfactors up to index 5. Slides from my talk at the IHP conferences "II1 factors: rigidity, symmetries and classification", May 27, 2011.

Knots, the Four-color Theorem, and von Neumann Algebras. Slides from my talk in the D.W. Weeks seminar at MIT, April 20, 2011.

Classification of Subfactors: Slides from ECOAS 2010 at Dartmouth College.

Constructing the extended Haagerup subfactor: Slides from WCOAS 2009 in Reno, NV.

Planar Algebras and Knots: A poster from the AWM poster session at the 2009 Joint Math Meetings in DC.

Generators and Relations for the Haagerup planar algebra: Handout from my talk at the University of Toronto, December 12, 2008.

Planar algebras and the Haagerup subfactor, at the University of Tokyo operator algebras seminar, October 23, 2008. Beamer slides

Exceptional Tensor Categories in Subfactor Theory, at the MFO (Mathematisches Forschungsinstitut Oberwolfach) Arbeitsgemeinschaft on Algebraic structures in conformal field theories, April 4, 2007. Extended Abstract.


Fun! Watch a video of me talking about the platonic solids. This was produced by Girls' Angle, a math club for middle school girls, as part of their Women In Math video series.

Last year and the year before, I taught the high school students' section of the Boston Math Circle. We had classes on knot theory, math and politics, auction theory, coding theory, and polytopes.

At the University of New Hampshire, I taught calculus 1 and multivariable calculus, and organized a graduate seminar on knot theory.

What am I like as a teacher? Here's a full transcript (with illustrations!) of a talk on platonic solids which I gave at the Davis Math Circle in March 2007.

Here are my job application materials from AY 2011-12: Research Statement, CV, Teaching Statement.
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