Skip to main content
edited tags
Link
Francesco Polizzi
  • 66.3k
  • 5
  • 180
  • 283
Source Link
Dario
  • 683
  • 1
  • 7
  • 20

Example of a triangulable topological manifold which does not admit a PL structure

I know there are some examples of manifolds which don't admit a PL structure (combinatorial triangulation), and that it has been recently proven that in dimension $n\geq5$ there are manifold which are not triangulable (i.e. which are not homeomorphic to a simplicial complex).

As far as I understand, in dimension $4$ the two concept (triangulable and PL) should coincide, while in dimension $n\geq 5$ they are different.

The only examples of non-combinatorial triangulations I have encountered are double suspensions of homology spheres (which are homeomorphic to spheres): so in that case there is a topological manifold which admit also non-combinatorial triangulations.

I was wondering if there are examples of topological manifolds which admit triangulations, but none of them is combinatorial.