Essential cohomology for elementary abelian p-groups
arXiv:0809.4425 · doi:10.1016/j.jpaa.2009.04.016
Abstract
For an odd prime p the cohomology ring of an elementary abelian p-group is polynomial tensor exterior. We show that the ideal of essential classes is the Steenrod closure of the class generating the top exterior power. As a module over the polynomial algebra, the essential ideal is free on the set of Mui invariants.
10 pages