In rational homotopy theory there are two concepts,formal and coformal spaces.I want to know example of a space which is 1)not formal and coformal, 2)rationally hyperbolic and not coformal.
1 Answer
In this paper you will find examples that fits with your first question: http://www.sciencedirect.com/science/article/pii/S0040938303000053 "Elliptic rational spaces whose cohomologies and homotopies are isomorphic" Tetsu Nishimotoa, Hiroo Shiga, Toshihiro Yamaguchi.
The authors consider a family of elliptic spaces that are not formal nor coformal. These examples are very interesting, they build two simply-connected closed smooth manifolds $M_1$, $M_2$ such that
they have isomorphic rational cohomology algebra,
they have isomorphic rational homotopy Lie algebras $\pi_*(\Omega M_i)\otimes \mathbb{Q}$,
they are not rationally homotopy equivalent.
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$\begingroup$ @Davic C,Thank you sir.The link you gave is not opening.Can you send me the email address of anyone of the authors?I tried to find by googling,but failed. $\endgroup$– PrateepCommented Nov 20, 2013 at 11:01