English

Generalisations of Hecke algebras from Loop Braid Groups

Geometric Topology 2023-05-31 v2 Quantum Algebra Representation Theory

Abstract

We introduce a generalisation LHnLH_n of the ordinary Hecke algebras informed by the loop braid group LBnLB_n and the extension of the Burau representation thereto. The ordinary Hecke algebra has many remarkable arithmetic and representation theoretic properties, and many applications. We show that LHnLH_n has analogues of several of these properties. In particular we %introduce consider a class of local (tensor space/functor) representations of the braid group derived from a meld of the (non-functor) Burau representation and the (functor) Deguchi {\em et al}-Kauffman--Saleur-Rittenberg representations here called Burau-Rittenberg representations. In its most supersymmetric case somewhat mystical cancellations of anomalies occur so that the Burau-Rittenberg representation extends to a loop Burau-Rittenberg representation. And this factors through LHnLH_n. Let SPnSP_n denote the corresponding quotient algebra, kk the ground ring, and tkt \in k the loop-Hecke parameter. We prove the following: 1) LHnLH_n is finite dimensional over a field. 2) The natural inclusion LBnLBn+1LB_n \rightarrow LB_{n+1} passes to an inclusion SPnSPn+1SP_n \rightarrow SP_{n+1}. 3) Over k=Ck=\mathbb{C}, SPn/radSP_n / rad is generically the sum of simple matrix algebras of dimension (and Bratteli diagram) given by Pascal's triangle. 4) We determine the other fundamental invariants of SPnSP_n representation theory: the Cartan decomposition matrix; and the quiver, which is of type-A. 5) The structure of SPnSP_n is independent of the parameter tt, except for t=1t= 1. \item For t21t^2 \neq 1 then LHnSPnLH_n \cong SP_n at least up to rankn=7n=7 (for t=1t=-1 they are not isomorphic for n>2n>2; for t=1t=1 they are not isomorphic for n>1n>1). Finally we discuss a number of other intriguing points arising from this construction in topology, representation theory and combinatorics.

Keywords

Cite

@article{arxiv.2008.04840,
  title  = {Generalisations of Hecke algebras from Loop Braid Groups},
  author = {Celeste Damiani and Paul Martin and Eric C. Rowell},
  journal= {arXiv preprint arXiv:2008.04840},
  year   = {2023}
}

Comments

v2, added references

R2 v1 2026-06-23T17:47:03.637Z