Categorifying induction formulae via divergent series
arXiv:1803.02899 · doi:10.1016/j.jalgebra.2019.02.031
Abstract
We show how to get explicit induction formulae for finite group representations, and more generally for rational Green functors, by summing a divergent series over Dwyer's subgroup and centralizer decomposition spaces. This results in formulae with rational coefficients. The former space yields a well-known induction formula, the latter yields a new one. As essentially immediate corollaries of the existing literature, we get similar formulae in group cohomology and stable splittings of classifying spaces.
30 pages, to appear in Journal of Algebra