English

The Andersen-Masbaum-Ueno conjecture for the derived subgroup of the Johnson kernel

Geometric Topology 2026-04-01 v1 Representation Theory

Abstract

A conjecture of Andersen, Masbaum and Ueno states that for any compact oriented surface Σg,n\Sigma_{g,n} and any pseudo-Anosov fMod(Σg,n),f\in \mathrm{Mod}(\Sigma_{g,n}), the matrix ρr(f)\rho_r(f) has infinite order for any large r,r, where ρr\rho_r is the SO(3)\mathrm{SO}(3)-WRT quantum representation of the mapping class group Mod(Σg,n)\mathrm{Mod}(\Sigma_{g,n}) at a primitive rr-th root of unity. We prove this conjecture for prime rr and any f[J2(Σg,n),J2(Σg,n)],f\in [J_2(\Sigma_{g,n}),J_2(\Sigma_{g,n})], where J2(Σg,n)J_2(\Sigma_{g,n}) is the Johnson kernel.

Keywords

Cite

@article{arxiv.2603.29397,
  title  = {The Andersen-Masbaum-Ueno conjecture for the derived subgroup of the Johnson kernel},
  author = {Renaud Detcherry},
  journal= {arXiv preprint arXiv:2603.29397},
  year   = {2026}
}