# Contents

## Idea

Poincaré‘s homology sphere is a closed 3-manifold with the same homology as the 3-sphere but with a fundamental group which is non-trivial.

## Realizations

…the coset space $SU(2)/2I$ of the special unitary group in dimension 2 by the binary icosahedral group.

## References

Created on January 11, 2016 at 17:57:48. See the history of this page for a list of all contributions to it.