David N. Yetter

Learn More
Using the theory of measurable categories developped in [Yet03], we provide a notion of representations of 2-groups more well-suited to physically and geometrically interesting examples than that using 2-VECT (cf. [KV94]). Using this theory we sketch a 2-categorical approach to the state-sum model for Lorentzian quantum gravity proposed in [CY03], and(More)
The 2-category of all small categories equivalent to a (finite) cartesian product of the category of finite dimensional vector spaces over a fixed field, left-exact functors, and natural transformations has structures closely mimicking those found in ordinary linear algebra. We examine these structures, the relation of this category to the 2-categories and(More)