Mod-two cohomology rings of alternating groups

Autor: Dev Sinha, Chad Giusti
Rok vydání: 2020
Předmět:
Zdroj: Journal für die reine und angewandte Mathematik (Crelles Journal). 2021:1-51
ISSN: 1435-5345
0075-4102
DOI: 10.1515/crelle-2020-0016
Popis: We calculate the mod-two cohomology of all alternating groups together, with both cup and transfer product structures, which in particular determines the additive structure and ring structure of the cohomology of individual groups. We show that there are no nilpotent elements in the cohomology rings of individual alternating groups. We calculate the action of the Steenrod algebra and discuss individual component rings. A range of techniques is needed: an almost Hopf ring structure associated to the embeddings of products of alternating groups, the Gysin sequence relating the cohomology of alternating groups to that of symmetric groups, Fox-Neuwirth resolutions, and restriction to elementary abelian subgroups.
Comment: 41 pages, 4 figures; v2: minor additions and updates; v3: new figures, substantial revisions to exposition
Databáze: OpenAIRE