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arXiv · 2112.10837

Constructing the Virasoro groups using differential cohomology

Arun Debray·Yu Leon Liu·Christoph Weis
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Abstract

The Virasoro groups are a family of central extensions of $\mathrm{Diff}^+(S^1)$, the group of orientation-preserving diffeomorphisms of $S^1$, by the circle group $\mathbb T$. We give a novel, geometric construction of these central extensions using "off-diagonal" differential lifts of the first Pontryagin class, thus affirmatively answering a question of Freed-Hopkins.

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BibTeXRIS

Arun Debray, Yu Leon Liu, Christoph Weis. 2021-12-20. Constructing the Virasoro groups using differential cohomology. https://doi.org/10.1093/imrn%2Frnad035

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