Formulae for the action of the Steenrod algebra on the mod 2 cohomology of a finite [italic]H-space are calculated. These formulae imply that the first nonvanishing homotopy group for a finite [italic]H-space occurs in degrees 1, 3, 7, or 15. The Steenrod algebra structure also restricts the coalgebra structure of the cohomology and Hurewicz map.
Formulae for the action of the Steenrod algebra on the mod 2 cohomology of a finite [italic]H-space are calculated. These formulae imply that the first nonvanishing homotopy group for a finite [italic]H-space occurs in degrees 1, 3, 7, or 15. The Steenrod algebra structure also restricts the coal...