Title of Paper:

On co-H maps to the suspension of the projective plane

Author(s):

Jie Wu

AMS Classification numbers:

55

Addresses of Authors:

Department of Mathematics
National University of Singapore
Singapore 117543
Republic of Singapore


Email address of Authors 

matwuj@nus.edu.sg

Included EPS or PS files:

coHspacewu.dvi

Text of Abstract (try for 20 lines or less): 


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 $\pi_n(S^3)$, 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.