English

Transgressive loop group extensions

Differential Geometry 2017-02-01 v3 Mathematical Physics math.MP

Abstract

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.

Keywords

Cite

@article{arxiv.1502.05089,
  title  = {Transgressive loop group extensions},
  author = {Konrad Waldorf},
  journal= {arXiv preprint arXiv:1502.05089},
  year   = {2017}
}

Comments

37 pages, 3 figures. In v2 the former Section 3.3 about Lie algebra splittings was withdrawn because of a gap in the proof of former Theorem 3.3.3. Best possible statement about Lie algebra splittings is now Proposition 4.9. In v3 typos and a mistake in Example 2.6 have been corrected; v3 is the published version

R2 v1 2026-06-22T08:31:56.626Z