English

Surface configuration kernels

Geometric Topology 2025-10-22 v1

Abstract

Let Σg,\Sigma_{g,*} be a once-punctured oriented surface of genus gg. We study the action of the mapping class group Γg,\Gamma_{g,*} on the nthn^{th} rational cohomology of the configuration space Confn(Σg,)\text{Conf}_n(\Sigma_{g,*}) of injections {1,,n}Σg,\{1,\ldots, n\}\hookrightarrow \Sigma_{g,*}, and compare the kernel Jg,cfg(n)J_{g,*}^{cfg}(n) of this action with the nthn^{th} Johnson subgroup Jg,(n)J_{g,*}(n). We find high-rank abelian subgroups in the quotient Jg,cfg(n)/Jg,(n)J_{g,*}^{cfg}(n)/J_{g,*}(n) arising from the higher Johnson images and from symplectic representation theory. In particular we refute a conjecture due to Bianchi--Miller--Wilson.

Keywords

Cite

@article{arxiv.2510.18261,
  title  = {Surface configuration kernels},
  author = {Andreas Stavrou},
  journal= {arXiv preprint arXiv:2510.18261},
  year   = {2025}
}

Comments

37 pages, 12 figures, 1 table