Odd generators of the mod 3 cohomology of finite $H$-spaces

Abstract

In this paper we derive a formula about the action of $\mathscr{P}^{1}$ on the odd generators of the mod 3 cohomology of a finite simply connected mod 3 $H$-space with associative mod 3 homology. This formula will be used in a subsequent paper to classify all possible cohomology rings that can occur as the mod 3 cohomology of such $H$-spaces.