2006/05/27 by Kai Behrend, Ping Xu, Behrend, Kai +1 · 8 citations
Mathematics · Medicine · #Advanced Operator Algebra Research #Differential Geometry (math.DG) #FOS: Mathematics #FOS: Physical sciences #Homotopy and Cohomology in Algebraic Topology #Mathematical Physics (math-ph) #Ophthalmology and Eye Disorders
paper · pdf · doi:10.48550/arxiv.math/0605694
openalex publication_date 2006/05/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We introduce differentiable stacks and explain the relationship with Lie groupoids. Then we study S1-bundles and S1-gerbes over differentiable stacks. In particular, we establish the relationship between S1-gerbes and groupoid S1-central extensions. We define connections and curvings for groupoid S1-central extensions extending the corresponding notions of Brylinski, Hitchin and Murray for S1-gerbes over manifolds. We develop a Chern-Weil theory of characteristic classes in this general setting by presenting a construction of Chern classes and Dixmier-Douady classes in terms of analogues of connections and curvatures. We also describe a prequantization result for both S1-bundles and S1-gerbes extending the well-known result of Weil and Kostant. In particular, we give an explicit construction of S1-central extensions with prescribed curvature-like data.