Title of Paper :Having the H-space structure is not a generic property

Author(s) : Jianzhong Pan

AMS Classification numbers :55P60,55P45

Addresses of Authors:



Institute of Math.,Academia Sinica ,Beijing 100080 ,China
email:pjz@math03.math.ac.cn






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

 In this note, we answer in negative  a question posed
 by McGibbon about the generic property of H-space structure.
 In fact we verify  the conjecture of
 Roitberg. Incidentally, the same example also answers
 in negative the  open problem 10 in McGibbon.