Orbifolds as Stacks?
نویسنده
چکیده
The goal of this survey paper is to argue that if orbifolds are groupoids, then the collection of orbifolds and their maps need to be thought of as a 2-category. This 2-category may be either taken to be the weak 2-category of groupoids, bibundles and equivariant maps between bibundles or the strict 2category of geometric stacks represented by proper etale Lie groupoids. While nothing in this paper is strictly speaking new, it is hoped that differential geometers unfamiliar with groupoids, bibundles and stacks would find it a useful introduction to the subject.
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