The purpose of this note is to announce a new isotopy invariant of oriented links of tamely embedded circles in 3-space. We represent links by plane projections, using the customary conventions thatâ€¦ (More)

In recent years, it has been discovered that invariants of three dimensional topological objects, such as links and three dimensional manifolds, can be constructed from various tools of mathematicalâ€¦ (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 thatâ€¦ (More)

We develop the theory of categories of measurable fields of Hilbert spaces and bounded fields of operators. We examine classes of functors and natural transformations with good measure theoreticâ€¦ (More)

Abstract: We provide, with proofs, a complete description of the authorsâ€™ construction of state-sum invariants announced in [CY], and its generalization to an arbitrary (artinian) semisimple tortileâ€¦ (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 naturalâ€¦ (More)