Finitistic Spaces with Orbit Space a Product of Projective Spaces

Abstract

Let G = Z2 act freely on a nitistic space X. If the mod 2 cohomology of X is isomorphic to the real projective space RP^{2n+1} (resp. complex projective space CP^{2n+1}) then the mod 2 cohomology of orbit spaces of these free actions are RP1 x CPn (resp. RP2 x HPn) [7]. In this paper, we have discussed converse of these results. We have showed that if the mod 2 cohomology of the orbit space X/G is RP1 x CPn (resp. RP2 x HPn) then the mod 2 cohomology of X is RP^{2n+1} or S1 x CPn (resp. CP^{2n+1} or S2 x HPn). A partial converse of free involutions on the product of projective spaces RPn x RP2m+1 (resp. CPn x CP2m+1) are also discussed.