I am an Associate Professor at the Mathematical Institute at the University of Oxford. My research is in algebraic and geometric topology, often in the borderlands with mathematical physics and quantum computer science. Lately I have been thinking about the structure of three- and four-dimensional topological field theories, about algebraic properties of fusion categories, about singularities of equidimensional maps of four-manifolds, and about quantum teleportation algorithms for anyons.

When I am not mathing, you might find me …
… skiing, usually at Squaw,
… doing yoga, often at Yoga Tree or with Sam or Kenny,
… climbing, at Brooks or Mission Cliffs or occasionally Castle Rock,
… running, most recently in the SF half marathon,
… and taking pictures, including at Mike and Tim’s wedding and Teena and Matt’s wedding.

In an earlier incarnation, I …
… studied ordinary language philosophy, mostly with Stanley Cavell,
… was a devotee of the American built environment, guided by John Stilgoe,
… and was a contributing editor and cofounder of a quarterly magazine, Topic.

I also keep tabs on what my friends and associates are up to …
… defining the relationship economy (REXpedition),
… creating alternative currencies (Bernal Bucks) and currency platforms (MetaCurrency),
… building educational games (Motion Math),
… researching locational privacy,
quantifying themselves,
… reshaping science journalism (Gonzo Labs),
… asking why (wdydwyd),
… and studying the science of mindfulness.