English

Irreducible representations of welded braid group

Group Theory 2024-12-31 v1

Abstract

In this paper we study irreducible matrix representations of the welded braid group WBnWB_n, also known as the group of conjugating automorphisms of a free group Fn.F_n. We prove that WBnWB_n has no irreducible representations of dimension r,r, where 2rn22\leqslant r\leqslant n-2 for n5.n\geqslant 5. We give complete classification of all extensions of irreducible representations of the braid group BnB_n to the welded braid group WBnWB_n of dimensions n1n-1 (for n7n\geqslant 7) and nn (for n7,n\geqslant 7, n8n\neq 8). Classification of all extensions of the irreducible n1n-1- dimensional reduced Burau representation is given for n5,n\geqslant 5, n6.n\neq 6. A new one-parameter family of n1n-1- dimensional irreducible representations of WBnWB_n is discovered. Classification of all extensions of the irreducible nn-dimensional standard representation (also known as Tong-Yang-Ma representation) is given for all n3.n\geqslant 3. New families of the 3-dimensional irreducible representations of WB3WB_3 are discovered.

Keywords

Cite

@article{arxiv.2412.21133,
  title  = {Irreducible representations of welded braid group},
  author = {Inna Sysoeva},
  journal= {arXiv preprint arXiv:2412.21133},
  year   = {2024}
}

Comments

49 pages

R2 v1 2026-06-28T20:52:30.461Z