TY - JOUR

T1 - Decompositions of the stable module infinity ∞-category

AU - Hunt, Joshua

PY - 2022

Y1 - 2022

N2 - We show that the stable module -category of a finite group decomposes in three different ways as a limit of the stable module -categories of certain subgroups of . Analogously to Dwyer's terminology for homology decompositions, we call these the centraliser, normaliser, and subgroup decompositions. We construct centraliser and normaliser decompositions and extend the subgroup decomposition (constructed by Mathew) to more collections of subgroups. The key step in the proof is extending the stable module -category to be defined for any -space, then showing that this extension only depends on the -equivariant homotopy type of a -space. The methods used are not specific to the stable module -category, so may also be applicable in other settings where an -category depends functorially on .

AB - We show that the stable module -category of a finite group decomposes in three different ways as a limit of the stable module -categories of certain subgroups of . Analogously to Dwyer's terminology for homology decompositions, we call these the centraliser, normaliser, and subgroup decompositions. We construct centraliser and normaliser decompositions and extend the subgroup decomposition (constructed by Mathew) to more collections of subgroups. The key step in the proof is extending the stable module -category to be defined for any -space, then showing that this extension only depends on the -equivariant homotopy type of a -space. The methods used are not specific to the stable module -category, so may also be applicable in other settings where an -category depends functorially on .

U2 - 10.1112/topo.12269

DO - 10.1112/topo.12269

M3 - Journal article

VL - 15

SP - 2298

EP - 2316

JO - Journal of Topology

JF - Journal of Topology

SN - 1753-8416

IS - 4

ER -