257 research outputs found
Classification of Pointed Fusion Categories of dimension 8 up to weak Morita Equivalence
In this paper we give a complete classification of pointed fusion categories
over of global dimension 8. We first classify the equivalence
classes of pointed fusion categories of dimension 8, and then we proceed to
determine which of these equivalence classes have equivalent categories of
modules. This classificaction permits to classify the equivalence classes of
braded tensor equivalences of twisted Drinfeld doubles of finite groups of
order 8.Comment: 16 page
Deligne Cohomology for Orbifolds, discrete torsion and B-fields
In this paper we introduce the concept of Deligne cohomology of an orbifold.
We prove that the third Deligne cohomology group of a smooth \'{e}tale groupoid
classify gerbes with connection over the groupoid. We argue that the -field
and the discrete torsion in type II superstring theories are special kinds of
gerbes with connection, and finally, for each one of them, using Deligne
cohomology we construct a flat line bundle over the inertia groupoid, namely a
Ruan inner local in the case of an orbifold.Comment: To be published in the Proceedings of the Summer School "Geometric
and Topological methods for Quantum Field Theory", Villa de Leyva, Colombia
(2001
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