English

Braid groups and symplectic Steinberg groups

Group Theory 2023-12-06 v5 Geometric Topology

Abstract

We construct a homomorphism ff from the braid group B2n+2B_{2n+2} on 2n+22n+2 strands to the Steinberg group associated with the Lie type CnC_n and with integer coefficients. This homomorphism lifts the well-known symplectic representation of the braid groups. We also describe the image and the kernel of ff.

Keywords

Cite

@article{arxiv.2201.07153,
  title  = {Braid groups and symplectic Steinberg groups},
  author = {François Digne and Christian Kassel},
  journal= {arXiv preprint arXiv:2201.07153},
  year   = {2023}
}

Comments

21 pages. The statement and proof of Theorem 5.7 have been corrected in Version 2. Sections 5.4 and 6 were added in Version 3. Remark 5.9 added in Version 4. In Version 5: slight changes in introduction, Section 4 and acknowledgement; two references added

R2 v1 2026-06-24T08:54:10.294Z