English

Bi-incomplete Tambara functors

Algebraic Topology 2021-04-22 v1

Abstract

For an equivariant commutative ring spectrum RR, π0R\pi_0 R has algebraic structure reflecting the presence of both additive transfers and multiplicative norms. The additive structure gives rise to a Mackey functor and the multiplicative structure yields the additional structure of a Tambara functor. If RR is an NN_\infty ring spectrum in the category of genuine GG-spectra, then all possible additive transfers are present and π0R\pi_0 R has the structure of an incomplete Tambara functor. However, if RR is an NN_\infty ring spectrum in a category of incomplete GG-spectra, the situation is more subtle. In this paper, we study the algebraic theory of Tambara structures on incomplete Mackey functors, which we call bi-incomplete Tambara functors. Just as incomplete Tambara functors have compatibility conditions that control which systems of norms are possible, bi-incomplete Tambara functors have algebraic constraints arising from the possible interactions of transfers and norms. We give a complete description of the possible interactions between the additive and multiplicative structures.

Keywords

Cite

@article{arxiv.2104.10521,
  title  = {Bi-incomplete Tambara functors},
  author = {Andrew J. Blumberg and Michael A. Hill},
  journal= {arXiv preprint arXiv:2104.10521},
  year   = {2021}
}
R2 v1 2026-06-24T01:23:58.342Z