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On Co-H-maps to the Suspension of the Projective Plane

J. Wu
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Abstract

We study co-H-maps from a suspension to the suspension of the projective plane and provide examples of non-suspension 3-cell co-H-spaces. These (infinitely many) examples are related to the homotopy groups of the 3-sphere. For each element of order 2 in $π_n(S^3)$, there is a corresponding non-suspension co-H-space of cells in dimensions 2, 3 and n+2. Our ideas are to study Hopf invariants in combinatorial way by using the Cohen groups.

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J. Wu. 2001-12-20. On Co-H-maps to the Suspension of the Projective Plane. https://arxiv.org/abs/math/0112220

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