# Transgressive loop group extensions

@article{Waldorf2015TransgressiveLG,
title={Transgressive loop group extensions},
journal={Mathematische Zeitschrift},
year={2015},
volume={286},
pages={325-360}
}
• K. Waldorf
• Published 2015
• Mathematics, Physics
• Mathematische Zeitschrift
A central extension of the loop group of a Lie group is called transgressive, if it corresponds under transgression to a degree four class in the cohomology of the classifying space of the Lie group. Transgressive loop group extensions are those that can be explored by finite-dimensional, higher-categorical geometry over the Lie group. We show how transgressive central extensions can be characterized in a loop-group theoretical way, in terms of loop fusion and thin homotopy equivariance.

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