Yi-Zhi Huang (Rutgers):
Twisted intertwining operators and nonabelian
orbifold theories
The study of two-dimensional conformal field
theories can in fact be reduced to the study of intertwining
operators. In particular, the study of orbifold conformal field
theories corresponds to the study of twisted intertwining
operators (intertwining operators among twisted modules).
However, for more than twenty years, there was even no
mathematical definition of twisted intertwining operators
when the twisted modules involved are associated to
non-commuting automorphisms of the vertex operator algebra.
In this talk, I will discuss a recently introduced notion of twisted
intertwining operator and the basic properties of such operators.
I will also present the main conjecture on nonabelian orbifold
theories in terms of these operators and discuss the applications.