Free incomplete Tambara functors are almost never flat

Autor: Hill, Michael A., Mehrle, David, Quigley, J. D.
Rok vydání: 2021
Předmět:
Druh dokumentu: Working Paper
Popis: Free algebras are always free as modules over the base ring in classical algebra. In equivariant algebra, free incomplete Tambara functors play the role of free algebras and Mackey functors play the role of modules. Surprisingly, free incomplete Tambara functors often fail to be free as Mackey functors. In this paper, we determine for all finite groups conditions under which a free incomplete Tambara functor is free as a Mackey functor. For solvable groups, we show that a free incomplete Tambara functor is flat as a Mackey functor precisely when these conditions hold. Our results imply that free incomplete Tambara functors are almost never flat as Mackey functors. However, we show that after suitable localizations, free incomplete Tambara functors are always free as Mackey functors.
Comment: V2: added section 6.1 on the restriction functor V3: Updated according to referee report. Accepted version, to appear in IMRN
Databáze: arXiv