I may email you... Prof Dan Margalit send me that paper once. I don't have my laptop with me now. But if you believe that result, is my proof make sense to you now?
@subhankar I'm sorry..I don't know any link. But I've read that paper sometimes back. And as I said the paper used more technical terms like Johnson homomorphism and all.
Torelli group generated by bounding pair of maps, but what Morita proved that, for constructing homology sphere all you need is torelli element genberated by sperating curves.
That is, given somne homology sphere there exists some heegard g- splitting of S^3 and some torelli elemet from that g-genus surface such that , regluing that will give you the resultant manifold.
@SubhankarD. Here I am not restricting genus... genus one case is the trivial... the theorem says that you can constructed homology sphere from torelli element when you allowed to vary your genus.
@SubhankarD. In that paper he mainly proved the statement which I mentioned in the 2 nd paragraph. I think the actual statement is a bit more complicated in terms of Johnson's homomorphism. If you want I can send you the paper. Are you convinced with the proof?
@BalarkaSen I forgot to tell you, but I got a nice answer of a question you asked (one year back) , ie. two vector bundle homeomorphic implies vector bundle isomorphic or not.
btw it's still a open question, what are the homotopy group of $S^2$. As of my knowledge, a recent paper proved that there are infinitely many non-zero homotopy group of $S^2$. That might help for $S^2\vee S^2$.